Metal depositing system and method for additive metal casting

Abstract

A metal deposition system (100) for molten-metal additive casting on one or more build tables (102, 104) is described. The system includes (a) one or more stationary input metal reservoirs (106) configured to contain metal and allocate movable-doses of metal; (b) one or more movable metal-dose reservoirs (108, 110) configured to convey a movable-dose of metal allocated from the stationary reservoir; (c) one or more deposition modules (112, 114) configured to receive a deposition-session dose of metal transferred from the movable metal- dose reservoir and to deposit molten metal in selected locations in the one or more build tables; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more movable metal-dose reservoirs; and wherein at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, comprises a melting module configured for melting the metal.

Description

[0001] METAL DEPOSITING SYSTEM AND METHOD FOR ADDITIVE METAL CASTING

[0002] FIELD OF THE DISCLOSED TECHNIQUE

[0003] The present invention relates to metal devices, systems, and methods for the additive casting of metals. More particularly, the present invention relates to a metal device, system, and method for controllable deposition of molten metal for additive metal casting.

[0004] SUMMARY OF THE DISCLOSED TECHNIQUE

[0005] According to one aspect of the invention, a metal deposition system for molten-metal additive casting on one or more build tables, comprises (a) one or more stationary input metal reservoirs configured to contain metal and allocate movabledoses of metal; (b) one or more movable metal-dose reservoirs configured to convey a movable-dose of metal allocated from the stationary reservoir; (c) one or more deposition modules configured to receive a deposition-session dose of metal transferred from the movable metal-dose reservoir and to deposit molten metal in selected locations in the one or more build tables; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more movable metal-dose reservoirs; and wherein at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, comprises a melting module configured for melting the metal.

[0006] The metal deposition system of the above aspect may further comprise a controllerfor controlling at least the one or more movable metal-dose reservoirs and the one or more deposition modules for depositing the molten metal at a casting-ready temperature. In the metal deposition system of the previous aspects at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoir, and the one or more deposition module which comprises the melting module, further comprises a solid metal feeder configured to feed solid metal to the melting module.

[0007] The metal deposition system may further comprise a first build table, a second build table and a single stationary input metal reservoir, wherein the first build table is associated with a first one or more movable metal-dose reservoirs and a first one or more deposition modules, the second build table is associated with a second one or more movable metal-dose reservoirs and a second one or more deposition modules, and wherein the first one or more movable metal-dose reservoirs and the second one or more movable metal-dose reservoirs are configured to receive a respective movabledose of metal allocated from the single stationary reservoir.

[0008] The metal deposition system of the previous aspect may comprise a first build table, a second build table and a single stationary input metal reservoir, wherein each of the one or more movable metal-dose reservoirs and the one or more deposition modules is interchangeably operable over the first build table and the second build table.

[0009] In the metal deposition system of the previous aspects, the controller may control one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movabledose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines over the build plane.

[0010] The metal deposition system of the previous aspect may further comprise sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0011] Another aspect of the invention is a metal deposition method for additive casting, comprising the operations of: (a) allocating movable-doses of metal contained in a stationary input metal reservoir to a movable metal-dose reservoir and receiving a movable-dose in the movable metal-dose reservoir; (b) conveying, by the movable metal-dose reservoir, the movable-dose over one or more build tables; (c) transferring a deposition-session dose of metal from the movable metal-dose reservoir to a deposition module and receiving the deposition-session dose in the deposition module; (d) melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module; (e) depositing, by the deposition module, the metal in a form of molten metal at casting-ready temperature in selected locations in the one or more build tables; and (f) controlling, by a controller, at least the movable metal-dose reservoir and the deposition module for depositing the molten metal at a casting-ready temperature.

[0012] The metal deposition method may further comprise the operation of: (g) containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of: (i) the stationary input metal reservoir; (ii) the movable metal-dose reservoir; and (iii) the deposition module.

[0013] Another aspect of the invention is a casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; and a controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system comprises (a) one or more stationary input metal reservoir configured to contain metal and allocate movable-doses of metal; (b) one or more movable metal-dose reservoir configured to convey the movable-dose over a build plane, and to transfer deposition-session doses of metal from the movable-dose; (c) one or more deposition module configured to receive a deposition-session dose of metal transferred from the movable metal-dose reservoir and to deposit metal in a form of molten metal in selected locations in the build plane; and (d) one or more travel modules for traveling over the build plane at least one of: (1) the one or more deposition module; and (2) the one or more movable metal-dose reservoir; and the controller is further to control at least the movable metal-dose reservoir and the deposition module for depositing the molten metal at a casting-ready temperature, wherein at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module, comprises a melting module configured for melting the metal.

[0014] In the casting system of the previous aspect, the respective at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoir, and the one or more deposition module which comprises the melting module, may further comprises a solid metal feeder configured to feed solid metal to the melting module.

[0015] In the casting system of the previous aspects, the controller may control one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movable-dose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines over the build plane. The casting system of the previous aspect may further comprise sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0016] In the metal deposition system according to the previous aspects, the one or more stationary input metal reservoirs may be configured to receive metal in the range of 200Kg. to 2000Kg; and / or the one or more movable metal-dose reservoirs may be configured to receive metal in the range of 5Kg. to 40Kg.; and / or the one or more deposition modules may be configured to receive metal in the range of 0.05Kg. to lOKg; and / or the one or more deposition modules may be configured to deposit metal in a deposition rate in the range of O.lcc / sec. to lOcc / sec.

[0017] In the metal deposition system according to the previous aspects, one or more of the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, may comprise an inoculation mechanism configured to add inoculants to the molten metal for adjusting metal properties.

[0018] In the metal deposition system according to the previous aspects, the controller may control one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movable-dose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines over the build plane. The metal deposition system according to the previous aspect may further comprise sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0019] According to some embodiments, which can be combined with other embodiments described herein, the movable metal-dose reservoir can be an intermediate stage configured to carry the movable metal dose, and having an actuator to move the metal-dose.

[0020] Another aspect of the invention is a casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; and a controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system is the metal deposition system according to the previous aspects.

[0021] Another aspect of the invention is metal deposition method for additive casting, comprising the operations of: (a) allocating movable-doses of metal contained in a stationary input metal reservoir to a movable metal-dose reservoir and receiving a movable-dose in the movable metal-dose reservoir; (b) conveying, by the movable metal-dose reservoir, the movable-dose over one or more build tables; (c) transferring a deposition-session dose of metal from the movable metal-dose reservoir to a deposition module and receiving the deposition-session dose in the deposition module; (d) melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module; (e) depositing, by the deposition module, the metal in a form of molten metal at casting-ready temperature in selected locations in the one or more build tables; and (f) controlling, by a controller, at least the movable metal-dose reservoir and the deposition module for depositing the molten metal at a casting-ready temperature.

[0022] The metal deposition may further include the operation of: (g) containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of: (i) the stationary input metal reservoir; (ii) the movable metaldose reservoir; and (iii) the deposition module.

[0023] In the metal deposition method according to the previous aspect, the input metal is may be solid state and wherein preparing the metal for deposition further comprises melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module.

[0024] In the metal deposition method according to the previous aspect, preparing the input metal for deposition may further comprise adjusting material properties by an inoculation mechanism in at least one of the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, and configured to add inoculants to the molten metal.

[0025] The metal deposition method according to the previous aspect may further comprise controlling, by the controller, one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movable-dose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines overthe build plane. The metal deposition method according to the previous aspect may further comprise controlling one or more of the parameters, by a controller responsive to readings of sensors indicative of at least one parameter selected from the one or more of the parameters consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume orflow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool.

[0026] In the metal deposition system according to the above aspects, the movable metal-dose reservoir may be an intermediate stage configured to carry the movable metal dose and having an actuator to move the metal-dose.

[0027] According to an aspect of the invention, a metal deposition system for molten-metal additive casting on one or more build tables, comprises (a) one or more stationary input metal reservoirs configured to contain metal and allocate movabledoses of metal; (b) one or more intermediate stages having at least an actuator configured to convey a movable dose of the solid input metal allocated from the stationary reservoir; (c) one or more deposition modules configured to receive a deposition-session dose of metal transferred from the movable metal-dose reservoir and to deposit molten metal in selected locations in the one or more build tables; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more movable metal-dose reservoirs; and wherein at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, comprises a melting module configured for melting the metal.

[0028] According to an aspect of the invention, there is provided a metal deposition system for molten-metal additive casting on one or more build tables, comprising (a) one or more stationary input metal reservoirs configured to contain metal and allocate movable-doses of metal; (b) one or more movable metal-dose reservoirs configured to convey a movable-dose of metal allocated from the stationary reservoir; (c) one or more deposition modules configured to receive a deposition-session dose of metal transferred from the movable metal-dose reservoir and to deposit molten metal in selected locations in the one or more build tables; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more movable metal-dose reservoirs; and (d) a controller for controlling at least the one or more movable metal-dose reservoirs and the one or more deposition modules for depositing the molten metal at a casting-ready temperature, wherein at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, comprises a melting module configured for melting the metal.

[0029] In the above-described metal deposition systems, the controller may control one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movable-dose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h)temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines over the build plane.

[0030] Each of the described metal deposition systems may further comprise sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0031] According to another aspect of the invention, there is provided a metal deposition system for molten-metal additive casting on one or more build tables, comprising (a) one or more stationary input metal reservoirs configured to contain input metal and allocate movable-doses of metal; (b) one or more movable metal-dose reservoirs configured to convey a movable-dose of metal allocated from the stationary reservoir; (c) one or more deposition modules configured to receive metal from the movable metal-dose reservoir and to deposit molten metal; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more movable metal-dose reservoirs; and (e) a controller for controlling the one or more stationary input metal reservoirs, the one or more movable metal-dose reservoirs, the one or more deposition modules and the one or more travel modules for preparing the input metal for deposition, wherein preparing the input metal for deposition comprises at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform at least one of the positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate.

[0032] According to yet another aspect of the invention, there is provided a metal deposition system for molten-metal additive casting on one or more build tables, comprising (a) one or more stationary input metal reservoirs configured to contain metal stock of metal pieces having predetermined shape, size, and weight and allocate a predetermined number metal pieces; (b) one or more movable metal-piece reservoirs configured to receive and convey a predetermined number metal pieces allocated from the stationary reservoir; (c) one or more deposition module configured to receive at least one metal piece from the movable metal-piece reservoir and to deposit molten metal in selected deposition locations in the one or more build tables; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition module; and (2) the one or more movable metal-piece reservoir; and (e) a controller for controlling at least the one or more stationary input metal reservoirs, the one or more movable metal-piece reservoirs and the one or more deposition modules for depositing the molten metal, wherein the one or more deposition modules comprises a melting module for melting a portion of the metal piece. In some embodiments, the deposition module is physically coupled to the movable metal-dose reservoir, and movable therewith. At least one of the deposition module and the movable metal-piece reservoir comprise a metal piece magazine configured to contain the predetermined number of metal pieces. At least one of the deposition module and movable metal-piece reservoir comprise a metal piece applicator configured to replace a partially-melted metal piece with a new metal piece. At least one of the deposition module and the movable metal-piece reservoir comprise a movable metal piece holder for holding the metal piece and the controller is further configured to control the movable metal piece holder to maintain a predetermined height between the portion of the metal piece and the melting module.

[0033] In some embodiments, the deposition module further comprises one or more shaft heaters configured to heat the molten metal after melting and before arrival to the selected deposition locations. In some embodiments, the deposition module further comprises one or more area heaters configured to heat a working area in the selected deposition locations. The controller is further configured to control the area heaters heat the working area at least one of: before metal deposition, during metal deposition and after metal deposition.

[0034] In some embodiments of the metal deposition systems, the controller controls one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movabledose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines over the build plane.

[0035] In some embodiments, the metal deposition systems further comprise sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0036] According to an aspect of the invention, a metal deposition method for additive casting, may comprise the operations of: (a) allocating movable-doses of metal contained in a stationary input metal reservoir to a movable metal-dose reservoir and receiving a movable-dose in the movable metal-dose reservoir; (b) conveying, by the movable metal-dose reservoir, the movable-dose over one or more build tables; (c) transferring a deposition-session dose of metal from the movable metal-dose reservoir to a deposition module and receiving the deposition-session dose in the deposition module; (d) melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module; (e) depositing, by the deposition module, the metal in a form of molten metal at castingready temperature in selected locations in the one or more build tables; and (f) controlling, by a controller, at least the movable metal-dose reservoir and the deposition module for depositing the molten metal at a casting-ready temperature. In some embodiments, the metal deposition method may further comprise the operation of (g) containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of: (i) the stationary input metal reservoir; (ii) the movable metal-dose reservoir; and (iii) the deposition module.

[0037] According to another aspect of the invention, a metal deposition method for additive casting may comprise the operations of: (a) allocating movable-doses of metal contained in a stationary input metal reservoir to a movable metal-dose reservoir and receiving a movable-dose in the movable metal-dose reservoir; (b) conveying, by the movable metal-dose reservoir, the movable-dose over one or more build tables; (c) receiving metal from the movable metal-dose reservoir and depositing molten metal; (d) depositing, by the deposition module, the metal in a form of molten metal at a deposition temperature in selected deposition locations in the one or more build tables; and (f) controlling, by a controller, at least the one or more stationary input metal reservoirs, the movable metal-dose reservoir, and the one or more travel modules for preparing the input metal for deposition, wherein preparing the input metal for deposition comprises at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform at least one of the positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate. If the input metal is in solid state, then preparing the metal for deposition further comprises melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module. In some embodiments, preparing the input metal for deposition further comprises adjusting material properties by an inoculation mechanism in at least one of the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, and configured to add inoculants to the molten metal.

[0038] According to yet another aspect of the invention, a metal deposition method for additive casting may comprise the operations he operations of: (a) allocating a predetermined number of metal pieces having predetermined shape, size, and weight contained in a stationary input metal reservoir to a movable metal-piece reservoir; (b) conveying, by the movable metal-piece reservoir, the a predetermined number of metal pieces over one or more build tables; (c) receiving at least one metal piece from the movable metal-piece reservoir; (d) by a melting module accommodated in deposition module, melting a portion of the metal piece; and (f) controlling, by a controller, at least the one or more stationary input metal reservoirs, the movable metal-piece reservoir and the deposition module for depositing molten metal in selected deposition locations in the one or more build tables.

[0039] The metal deposition method may further comprise controlling a metal piece holder accommodated in one of the movable metal-piece reservoir and the deposition module to maintain a predetermined height between the portion of the metal piece and the melting module. The metal deposition methods according to embodiments of the invention may further comprise controlling, by the controller, one or more parameters selected from the list including: (a) transport speed of the movable metal-dose reservoir; (b) travel speed of deposition module; (c) movable-dose transferring rate to the movable metal-dose reservoir; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the movable metal-dose reservoir; (i) deposition progress along a deposition path over the build plane; and (j) distance between adjacent deposition path lines over the build plane.

[0040] The metal deposition methods according to embodiments of the invention may further comprise controlling one or more of the parameters, by a controller responsive to readings of sensors indicative of at least one parameter selected from the one or more of the parameters group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool.

[0041] According to aspects of the invention, there are provided various casting systems for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the systems comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; and a controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system is construed according to the embodiments described herein.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The disclosed technique will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

[0044] Figure 1 is a schematic illustration depicting an embodiment constructed and operative in accordance with the invention featuring principal components;

[0045] Figure 2 depicts a system arrangement that exemplifies several options for implementing embodiments constructed and operative in accordance with the invention;

[0046] Figure 3 is a schematic illustration depicting an embodiment of a system constructed and operative in accordance with the invention featuring a cascade of crucibles;

[0047] Figures 4 and 5 are schematic cross-sectional illustrations of a plunger crucible and a crucible cascade constructed and operative in accordance with embodiments of the invention, featuring start / stop and flow control;

[0048] Figures 6A-6B are detailed views of a rod load manipulator operational for advancing a horizontally disposed metal rod in accordance with embodiments of the invention;

[0049] Figures 7A-7C are schematic cross-sectional illustrations of a metal deposition system in accordance with embodiments of the invention;

[0050] Figures 8A-8B are schematic illustrations of metal deposition systems according to other embodiments of the invention; Figures 9A-9B are flow charts of methods for additive metal casting operative in accordance with embodiments of the invention; and

[0051] Figure 10 is a schematic block diagram of a casting system employing the metal deposition system according to embodiments of the invention.

[0052] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] In traditional casting, molten metal deposition involves a single-shot discharge of molten metal into a fully-fabricated mold, preferably as fast as possible. Molten metal flow is often designed to overcome flow obstacles associated with holes, windows, and additional metal cast features. However, for additive casting according to embodiments of the invention, the discharge of molten metal in a controlled manner is required. The metal (or metallic) object is fabricated in a series of production layer fabrication operations carried out on a build table. In each production layer, a mold region (e.g. a mold layer) is first fabricated. Upon completion of the mold region (e.g. the mold layer) of the current production layer-the object region is fabricated by depositing molten metal into the mold region. Thus, molten metal is deposited in a cyclic manner. A certain amount of time - the time needed for mold region construction - lapses between one molten metal deposition in one production layer and the successive molten metal deposition in the subsequent production layer. The production environment - the build table and the previously produced production layers, experience a cyclic thermal regime: the production temperature of the mold regions may differ from the production temperature of the object regions.

[0054] It is an object of embodiments of the present invention to provide metal devices, systems, and methods for effectively manufacturing metal objects by additive casting with molten metal using solid metal or molten metal as metal input. Metal rods and billets with pre-determined weight, shape, and metal properties, as well as scrap, may be used. The invention is not limited by the type of solid metal input. Any metallic material that can be melted or otherwise liquefied may be used with the required modifications.

[0055] Examples of metallic materials that may be used are metals and alloys, for example grey iron, ductile iron, steel, Inconel, titanium alloys, cast iron alloys and the like.

[0056] It is another object of the present invention to facilitate a fast and robust additive casting process by molten metal deposition, and in particular, to provide an agile, maneuverable deposition module, applicator, or depositor while maintaining its adequate feed by molten metal and to facilitate control of at least deposition position, pace or rate and temperature, and metal properties.

[0057] Embodiments of the invention allow controlling the position, deposition rate, and temperature of molten metal, as well as the mechanical and / or chemical and / or metallurgical properties of the molten metal independently from other parameters, as needed to ensure an improved or optimal process both in terms of quality (metallurgywise and geometrically) and in deposition throughput.

[0058] According to embodiments of the invention, the metal deposition system comprises multi-tier metal modules ending with a deposition module. The deposition module is advanced over a build plane (for example, one or more build tables), delivering molten metal of a desired specification (mechanical and / or chemical and / or metallurgical properties) to desired locations at a desired temperature and discharge rate. Various preparation operations of the molten metal for deposition may be distributed among the first, second, and third tiers.

[0059] According to another aspect of the invention, there is provided a metal casting system for additive casting that incorporates a multi-tier metal deposition system. According to yet another aspect of the invention, there is provided a metal casting method for additive casting that incorporates operating a multi-tier metal deposition system. Examples of systems and methods for additive casting with molten metal are illustrated in PCT patent applications publication numbers WO2019053712A1, W02023002468 and WO2022243921A1 assigned to the assignee of the present application, which are incorporated herein by reference.

[0060] A three-tier architecture: according to an aspect of the invention, there is provided a metal system constructed in a three-tier configuration - hierarchical tiers of metal retaining and allocating components: a first, stationary tier, a second, metalcarrying movable tier, and a third, deposition tier. The first tier features a stationary reservoir, the second tier features an intermediate stage having at least an actuator, and the third tier features a deposition module.

[0061] The intermediate stage having at least an actuator or movable reservoir of the second tier may, for example, be an arm, or other means which is intermediate stage configured to convey a piece of solid carry the movable metal, for example a rod, from the first tier to dose, and having an actuator to move the third tier. Alternatively, the intermediate stage having at least an actuator may, for example, be or comprise a movable metal-dose reservoir, metal-dose.

[0062] The intermediate stage may be configured to convey, for example pieces of solid metal, or molten metal, from the first tier to the third tier.

[0063] The three tiers may differ therebetween in several aspects: according to some embodiments, each tier is aimed at handling a different amount of metal. For example, the first tier handles the largest amount of metal (e.g. a first amount of metal); the second tier - the metal-carrying intermediate stage having at least an actuator, carries a smaller amount of metal (e.g. a second amount of metal) between the first tier and the deposition module; and the third tier - the deposition module - may handle the smallest amount of metal (e.g. a third amount of metal), for example in a volume facilitating controllable heating and deposition and accurate positioning. For example, the additive metal depositing system may be configured with the stationary input metal reservoir containing metal in the range of 250-1000Kg, the intermediate stage accumulating metal in the range of 2.5-50Kg, while the deposition module configured to receive up to 1.5Kg of metal and to deposit metal at the pace or rate of up to lOcc / sec (or slower). According to some embodiments, which can be combined with other embodiments described herein, the first amount of metal is larger than the second amount of metal and the third amount of metal, particularly by at least a factor of 10. Optionally, in addition, the second amount of metal may be larger than the third amount of metal.

[0064] Accordingly, the stationary input metal reservoir (tier 1) is configured to contain, dispense, and allocate metal. The intermediate stage having at least an actuator (tier 2) is configured to obtain solid or molten metal allocated from the stationary reservoir for accumulating a dose of the metal, optionally melting the metal, may be configured for transporting the dose over a build plane, and transferring the dose of the molten metal. The deposition module is operational for receiving molten metal from the intermediate stage and for depositing the molten metal in selected locations in the build plane according to a building plan. The controller is operational for controlling at least the intermediate stage and the deposition module for depositing the molten metal at a casting-ready temperature and at the desired rate.

[0065] The movable metal-dose reservoir (tier 2) may be an intermediate stage configured to carry the movable metal dose, and having an actuator to move the metaldose. If the input metal is in the form of rods, tier 2 may include an arm, or a rod holder. The arm, or the rod holder, may obtain a rod from the stationary input metal reservoir (tier 1), and transport the rod to tier 3. As another example, if the melting is carried out in tier 2, the intermediate stage may comprise a crucible comprising a melting module, and the actuator may be a travel module to travel the intermediate stage, or to travel the crucible.

[0066] The three-tiers metal deposition system may be accommodated by an additive casting system and be operable therewith. Among other elements, the casting system comprises a building table defining a building plane over which the intermediate stage and the movable deposition module travel. In some embodiments, the building table is assigned with one or more stationary reservoirs, one or more intermediate stages and one or more deposition modules.

[0067] The three-tier architecture facilitates controllability, repeatability and high throughput, at industrial scaling, of the casting process, particularly for vehicle components, truck components, train components, engine components, axles components, gear components, robotic components, heavy duty components and tooling components. The components can have a weight of 10 kg or above, such as 100 kg or above or even 1000 kg or above.

[0068] Also, in some embodiments, it is possible to combine or integrate tiers. In some embodiments, tiers 1 and 2 may be integrated. For example, the movable metaldose reservoir or intermediate stage may be coupled to, or mounted onto, the stationary input metal reservoir, any may include an arm which transfers doses of metal from the stationary input metal reservoir to the deposition module.

[0069] Alternatively, in some embodiments, tiers 2 and 3 may be integrated. For example, the deposition module may be coupled to, or mounted onto, the movable metal-dose reservoir or intermediate stage.

[0070] To increase casting throughput, improve footprint and cost-of-ownership, the additive casting system may include two or more building tables. In some embodiments, a single stationary input metal reservoir (tier 1) may serve the two or more building tables. In some embodiments, two or more movable metal-dose reservoirs are provided and serve the two or more building tables interchangeably. Additionally or alternatively, two or more deposition modules are provided and serve the two or more building tables, wherein a single stationary input metal reservoir and a single intermediate stage is provided.

[0071] The first tier is termed herein 'the stationary input metal reservoir'. The term 'stationary' indicates that while the second tier and third tier can move during the iterative deposition of metal into the object region of the multiple production layers - the first tier can essentially remain stationary during the deposition process. It should be understood that the input metal replenishment in the stationary input metal reservoir may or may not involve moving the stationary input metal reservoir. For example, the input metal may be fed into the stationary input metal reservoir by a crane (or any other load / unload system) lifting e.g., a pile of metal billets or rods, with or without moving the stationary input metal reservoir toward the crane. In another example, the load / unload system may replace the stationary input metal reservoir as a whole.

[0072] Several alternatives are provided for the three-tier configuration depending upon the type of input material - solid input metal or molten metal.

[0073] In large metal foundries, the melting of input solid metal often takes place in very large melting stations that can handle, for example, 50-60 tons of metal. In such cases, the three-tier architecture may receive the input metal in molten state.

[0074] Various solid input metal types may be used, such as rods, billets, pebbles, ingots, ore, pig iron casting system and scrap. According to solid metal input aspects of the invention, metal preparation and specifically, metal melting may take place in the stationary reservoir, or in the movable reservoir.

[0075] Allocation of operations among the three tiers: According to some embodiments, different preparation operations are distributed among the tiers. The preparation operations can be classified into four main preparation operations: (1) positioning; (2) temperature; (3) deposition flow rate; and (4) metal properties - mechanical, chemical and metallurgical properties. The preparation operations may comprise, for example, volume and / or weight measurements and adjustments; chemical composition measurements and adjustments; mechanical properties measurements and adjustments; metallurgical properties measurements and adjustment; positioning; heating / cooling to a casting-ready temperature; deposition flow rate.

[0076] The preparation operations may be implemented using, inter-alia, travel modules (e.g., robots), heating units (e.g., using induction heating), crucibles, and inoculants and additives. The three tiers may differ therebetween in the assignment and distribution of the preparation operations and consequently, in their hardware configuration.

[0077] For example, if solid metal is used as input, the melting and correspondingly, the use of inoculants and additives, may be assigned to tier 1 or 2. The invention is not limited by the type of inoculation mechanism that is used. For example, if one or more crucibles are used, inoculant wire, inoculant block, inoculant dispensing means and additional mechanisms may be used.

[0078] In some embodiments, different heating regimes are implemented in the various tiers. Factors such as precise control of the melting, or the melt aging (i.e., evaporation of additives and trace elements as well as oxidation of the melt over time) can be controlled for process optimization and cast quality. In some embodiments, melting and heating of metal to casting-ready temperature is performed at the first and / or second tier, and flow-rate of molten metal is controlled at the third tier. In some embodiments, melting is performed at the first and / or second tier, and heating to casting-ready temperature is performed at the third tier.

[0079] In yet another example, different measurements and assessments are performed in the various tiers, and corrective operations are implemented in response to the measurements and assessments. The corrective operations may be implemented in the same tier or in a downstream tier.

[0080] For example, the mechanical, chemical and / or metallurgical properties of the input metal may be measured in the first tier, and in response, inoculants may be added in the first, second and / or the third tier.

[0081] In the case that additives or inoculants are applied to the metal, the mechanisms for applying the additives or inoculants may be provided either at tier 1 (e.g., in the molten metal input embodiments), tier 2, and / or tier 3. In some embodiments, different additives or inoculants are applied to the metal at more than a single tier. The invention is not limited by the manner of additive or inoculant application.

[0082] In the case of air delivery, the additive or inoculant may be added in the form of gas-assisted powder distribution and the powder feeding mechanism may comprise a powder dosing system and powder nozzle / s for shooting powder doses of additive or inoculant into the molten metal. In other embodiments, the additive or inoculant may be inoculant wire, inoculant block, inoculant dispensing means. For example, the mechanism for applying the additive or inoculant in the form of a wire may comprise a wire feeder / injector, and dispersion and mixing means for dispersing and mixing the additive or inoculant e.g., in a crucible containing the molten metal before it is deposited.

[0083] The invention is not limited by the type of additives and inoculants that are used. For example, in the case of iron casting, alloys of silicon, manganese, copper, aluminum, strontium and more can be used.

[0084] Crucibles, crucible swap, crucible cascade: In some embodiments, one or more crucible and crucible units may be used. Crucibles in various types and sizes may be used. The crucible units may comprise a crucible swap station for providing the movable reservoir and / or deposition module with a filled crucible and receiving an empty crucible for a refill.

[0085] The crucible swap may occur at any tier which comprises crucibles. For example, the crucible swap may occur at any one or more of tier 1, tier 2, or tier 3. Optionally, one or more crucible swap stations can be provided at any one or more of tier 1, tier 2, or tier 3. For example a crucible swap may occur for crucibles of the one or more stationary input metal reservoirs, and / or for crucibles of the one or more movable metal-dose reservoirs or intermediate stages having an actuator, and / or for crucibles of the one or more deposition modules. According to some embodiments, which can be combined with other embodiments described herein, the crucible swap may beneficially be implemented at tier 3, i.e. the deposition module. For example, variations in material composition can be implemented for a crucible swap at tier 3, A crucible replenish station may also be provide at any one or more of tier 1, tier 2, or tier 3.

[0086] In some embodiments, the crucible units may comprise a crucible cascade for facilitating heating, flow rate control and / or metal properties measurements and adjustments. In some embodiments, flow-rate control is performed at the third tier. In other embodiments, flow-rate control is implemented - fully or partially - at the second tier.

[0087] Embodiments of the disclosed invention harness different techniques for allowing a controlled, fast and accurate deposition of molten metal for additive metal casting.

[0088] Melting at tier 1: In accordance with some aspects of the invention, the stationary input metal reservoir includes a solid input-metal feeder, the melting module, and a stationary molten metal crucible. The intermediate stage includes a movable crucible for receiving the movable-doses as molten metal from the stationary input metal reservoir. The solid input-metal feeder feeds solid input-metal (e.g., rods, billets, ingots, pebbles, scrap, etc.) to the melting module, the melting module melts the fed solid input metal into the stationary molten metal crucible, and the stationary molten metal crucible is configured to allocate the movable-doses of metal as molten metal to the movable crucible.

[0089] The movable metal-dose reservoir may be an intermediate stage configured to carry the movable metal dose, and having an actuator to move the metal-dose. When melting at tier 1, the actuator may move the crucible to receive the molten metal from the stationary input metal reservoir, and to transfer a dose of molten metal to the deposition module.

[0090] In some embodiments, the melting may occur before tier 1. For example, in some embodiments, tier 1 may receive molten metal from a metal foundry furnace or the like. Melting at tier 2: In accordance with some aspects of the invention, the stationary input metal reservoir includes solid input-metal feeder, and an input metal dosage allocator for allocating the movable-dose in the form of a solid-dosage portion of input metal to the intermediate stage. The intermediate stage (tier 2) may include the melting module. For example, the intermediate stage that includes a melting module may be realized as a crucible integrated with a heating unit for melting the allocated metal (e.g., scrap, pebbles, ingots) and discharge molten metal.

[0091] In some embodiments, the intermediate stage (tier 2) and the deposition module (tier 3) are movable together. For example, the deposition module may be coupled to the intermediate stage. In another example, the movement of the deposition module may be synchronized with the movement of the intermediate stage.

[0092] The movable metal-dose reservoir may be an intermediate stage configured to carry the movable metal dose, and having an actuator to move the metal-dose. When melting at tier 2, intermediate stage may include the melting module. For example, the movable metal-dose reservoir that includes a melting module may be realized as a crucible integrated with a heating unit for melting the allocated metal (e.g., scrap, pebbles, ingots), wherein the crucible is also configured to discharge molten metal.

[0093] In some embodiments, intermediate stage (tier 2) and the deposition module (tier 3) are movable together. For example, the deposition module may be integrated with the intermediate stage. In another example, the movement of the deposition module may be synchronized with the movement of the intermediate stage.

[0094] Melting at tier 3: in accordance with some aspects of the invention, the stationary input metal reservoir includes a solid input-metal feeder and an input metal dosage allocator for allocating the movable-dose in the form of a solid-dosage portion of input metal to the movable metal-dose reservoir. The movable metal-dose reservoir includes a deposition-session solid-dosage allocator for allocating a deposition-session solid-dosage portion in solid from the movable-dose to the deposition module. The deposition module includes the melting module for melting the solid deposition-session solid-dosage portion for discharging as molten metal. The deposition module can further include a deposition molten metal buffer crucible, wherein the melting module melts the solid deposition-session solid-dosage portion for discharging as molten metal into the deposition molten metal buffer crucible.

[0095] In tier 3, one option for controlling the deposition rate of the molten metal is to use a plunger or to use a cascade of two or more crucibles, which will be described later.

[0096] Furthermore, the use of a cascade of two or more crucibles is not limited to the case of melting at tier 3, and can be applied to any of the tiers. Also, a cascade of crucibles can also include crucibles in other tiers, for example a cascade of one crucible in tier 1, and another crucible in tier 2, or a cascade of one crucible in tier 2, and another crucible in tier 3.

[0097] The movable metal-dose reservoir may be an intermediate stage configured to carry the movable metal dose, and having an actuator to move the metal-dose. When melting at tier 3, the intermediate stage includes a deposition-session solid-dosage allocator for allocating a deposition-session solid-dosage portion in solid from the movable-dose to the deposition module.

[0098] Input metal rods: metal rods, bars and billets - and other metal pieces that come in determined weights, shapes and material properties, may hierarchically constitutes the second tier of intermediate stage. By fetching a rod, a bar or a billet contained in the stationary metal input reservoir - a known amount of metal with known material properties (microstructure and other metallurgical properties, mechanical properties, chemical properties) is easily allocated by a robot, a magazine or any other unit designed to fit the predetermined shape and weight of the input metal piece.

[0099] For example, in one configuration of the metal rod input embodiments the melting takes place at the third tier. The stationary reservoir comprises a rod station for providing the movable reservoir with one or more rods. The deposition module may comprise a rod holder for holding the input rod. In some embodiments, an additional element - a rod magazine unit for holding more than a single rod is incorporated, to thereby reduce the number and frequency of rod replenishment travels.

[0100] When melting at tier 1, 2 or 3, the input metal may be one or more rods, bars, wires, ores, scrap, pig iron, or the like. Rods or bars can be advantageous in having fixed specifications, such as composition, cleanliness, etc. Rods and bars can also be advantageous in having a fixed weight and / or shape, and they can be easy to move and manipulate, for example, compared to pebbles, grains, scrap metal, etc. Ores or ingots can, in some cases, also be have a well-determined specification, and can be deposited as-is.

[0101] Melting at tier 2 or tier 3 can be advantageous in terms of the balance between metal fabrication and mold construction. This is because, between metal deposition of consecutive layers, in some embodiments, the metal head may wait for the completion of the respective mold region. Melting at tier 2 or tier 3 can provide 'on demand' melting, whereby it is not required to maintain a large stock of molten metal.

[0102] When using metal pieces such as rods, bars and billets as input, tier 2 may be integrated with the third tier.

[0103] Tier 3 - the deposition module: in accordance with some aspects of the invention, the deposition module receives molten metal as input. In some embodiments, the melt temperature upon melting - especially as melting takes place before the third tier, is not adequate for casting. Accordingly, the deposition module includes a castingready heater operational for heating molten metal into an additive-casting-temperature adequate for additive casting at the casting locations. In some embodiments, the molten metal enters the deposition module at a melting temperature and exits the deposition module at a casting-ready temperature which is higher than the melting temperature (over heating), for depositing in selected locations in the build plane at the casting-ready temperature. In some embodiments of the invention, the molten metal enters the deposition module at an over-melting temperature and exits the deposition module at a casting-ready temperature which is equal to the melting temperature or above, and lower than the over-melting temperature. The various deposition heating regimes may be aligned, monitored and controlled together with pre-deposition, during deposition and post deposition area heating.

[0104] Travel and travel control, other control aspects, sensors: In accordance with some aspects of the invention, the metal deposition system further includes a travel module for traveling over the build plane at least one of: the deposition module, and the intermediate stage. The deposition module and the intermediate stage may travel independently from each other, or share a common travel unit.

[0105] In accordance with some aspects of the invention, the controller controls one or more parameters selected from the list including: transport speed of the intermediate stage, travel speed of the deposition module, movable-dose transferring rate to the intermediate stage, inoculants and additive regime, deposition-session dose transferring rate to the deposition module, melting rate of the melting module, melt heating regime, deposition rate of the deposition module, amount of material in the movable reservoir, amount of material in the deposition module, temperature of the metal in the deposition module, temperature of the metal in the intermediate stage, deposition progress along a deposition path over the build plane, and distance between adjacent deposition path lines over the build plane.

[0106] For example, the deposition rate may be controlled by the velocity of tier 3, i.e., the deposition module, or by a crucible with a plunger, or by a cascade of crucibles.

[0107] In accordance with some aspects of the invention, the controller is configured to control the depositing of the molten metal at a controlled rate, by controlling one or more of: transporting speed of the intermediate stage, dose transferring rate of the molten metal to the intermediate stage, travel speed and direction of the deposition module, and deposition rate of the deposition module.

[0108] In accordance with some aspects of the invention, the controller is configured to control a start and a stop of deposition during additive metal casting by controlling one or more of: molten metal dose transferring by the intermediate stage, and molten metal deposition by the deposition module. In accordance with some aspects of the invention, the metal deposition system further includes sensors, indicative of at least one parameter selected from the group of: temperature of molten metal incoming to the deposition module, temperature of molten metal outgoing from the deposition module right before depositing in the build plane, volume or flow rate of molten metal incoming to the deposition module (for example, sensing and determining the drip count and / or width of stream), volume or flow rate of molten metal outgoing from the deposition module (for example, sensing and determining the drip count and / or width of stream), and liquid height of molten metal in a crucible or pool in any of the tiers, temperature of metal in the working areas (deposition locations) before additive casting, temperature of metal in the working areas (deposition locations) after additive casting, parameter of an additive, inoculant, or oxidation-shielding in deposition location before additive casting, and parameter of an additive, inoculant, or oxidation-shielding in deposition location after additive casting, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters. The sensors may reside in a single tier (first, second, third) or distributed among the first, second, third as needed.

[0109] Working area heating: In accordance with further aspects of the invention, the deposition module may be positioned in proximity to the working areas - the areas on which the molten metal is to be deposited. In some embodiments, additional heaters - working area heaters (also referred to as surface heaters) such as pre-deposition heater / s, area deposition heater / s and / or post-deposition heater / s - may be placed in proximity to the working areas, for providing pre-deposition heating, during-deposition heating, and / or post-deposition heating of the working areas (the surface of the object region currently produced) to thereby improve bonding and impact the metal cooling profile. In some embodiments, the working area heater / s may be physically and / or operably coupled to the deposition module as a separate melting-depositing-surface heating module. For example, the area heater / s may be carried by the travel unit that moves the deposition module over the build plane. In another example, the controller that controls the deposition temperature further controls the operation of the working area heater / s such that the control of the molten metal upon deposition will take into account the effect of all the heat sources operating in proximity to the working areas and the molten metal drops (or stream) upon deposition.

[0110] In accordance with some aspects of the invention, the working area heater / s includes at least one heating element encircling the deposition module over the build plane. In accordance with some aspects of the invention, the heating elements can be rotated about the deposition module.

[0111] Protective environment: In some embodiments, various parts of the metal deposition system further include a protective environment. For example, the deposition module may be provided with a tubular protective sleeve disposed between the deposition module and the working areas for shielding at least the molten metal to be deposited, wherein the sleeve includes e.g., a single or double walled funnel in which oxygen retarding gas (such as nitrogen or argon) is streamed for local purging. Embodiments of the present disclosure including a 3 tier concept, particularly with melting at tier 3, allows to reduce or limit the space in which protective environment is provide for the casting system.

[0112] Reference will now be made to the Figures, wherein like numbers denote like parts for clarity.

[0113] A three-tier molten metal deposition system for additive casting

[0114] Reference is now made to Figure 1, which is a partial, schematic illustration depicting an embodiment, denoted as metal deposition system 100, constructed and operative in accordance with embodiments of the invention featuring principal components. Metal deposition system 100 is operational for additive-casting with molten metal over two build tables represented by perforated rectangles 102 and 104. Build tables 102 and 104 are used for additive casting, one production layer after another. Each production layer includes mold regions (not shown) defining object regions (not shown) into which molten metal is to be deposited. The first production layer may comprise only a mold region. After completing the production of the mold regions and object regions of a production layer -the production of the next layer starts. Each of build tables 102 and 104 defining a build plane per production layer. In each production layer, the mold region may be constructed by a mold constructing system (not shown). For example, the mold structure may be deposited, in-situ, by a mold deposition system (not shown). For another example, a plurality of layered mold structures is fabricated at a remote location (not shown), transferred to the build table and constructed (not shown).

[0115] The additive casting system that incorporates the metal deposition system 100 may further comprise additional systems, elements and components such as mold surface treatment elements, metal surface treatment elements, heaters, robots or other motion arrangements, inert gas elements, and additional elements (not shown).

[0116] The metal deposition system 100 is movable over the build plane (X-Y direction). The mold construction system and other systems and elements of the additive casting system are movable (not shown). The build table / s may be movable over the build plane (X-Y directions). The build table / s may be relatively movable in the Z direction with respect to the metal deposition system, the mold construction system and other systems and elements of the additive casting system. A metal object and its respective mold structure (or more than a single cast) are than manufactured layer by layer on the build table / s.

[0117] In the example of Fig. 1, metal deposition system 100 includes a single stationary input metal reservoir 106, two intermediate stages 108 and 110, or movable metal-dose reservoirs, two deposition modules 112 and 114, and controller 116.

[0118] Stationary input metal reservoir 106 contains a large amount of metal and serves as a dispensing station serving to allocate metal doses to intermediate stages 108 and 110. Such doses are sometime referenced herein as a "movable dose" or "movable metal dose" and can be solid or molted. Intermediate stages 108 and 110, respectively receive, accumulate the obtained doses, transport them over the build table 102, or 104, and respectively allocate, and transfer, deliver or feed deposition-session doses (which may be smaller than the movable doses) to deposition modules 112 and 114, at desired paces or rates. Deposition modules 112 and 114 which receive deposition session doses of molten or solid metal, deposit the metal in the form of molten metal in selected locations in respective build plane of build tables 102 or 104.

[0119] Controller 116 controls at least intermediate stage 108 / 110 and deposition module 112 / 114 for depositing the molten metal at a casting-ready temperature. At least one of: stationary input metal reservoir 106, or intermediate stage 108 / 110, comprises a melting module which is configured for melting solid metal into molten metal.

[0120] Metal deposition system 100 includes maneuvering means 118, 120 and 122. Intermediate stage 108 is movable by maneuvering means 118, deposition module 112 is movable by maneuvering means 118.

[0121] According to embodiments of the invention, illustrated in build table 102, intermediate stage 108 and deposition module 112 are capable of moving independently of each other.

[0122] According to embodiments of the invention, illustrated in build table 104, the deposition module 114 is physically coupled to intermediate stage 110 and movable therewith. In Figure 1, intermediate stage 110 and deposition module 114 are coupled together in a single encasement 124 and therefore are movable by a single maneuvering means 122.

[0123] Controller 116 is connected to and operational for controlling the operation of stationary input metal reservoir 106, and the operation and movement of intermediate stages and their respective maneuvering means 118 and 122, deposition module and its maneuvering means 120, and deposition module 114 (which is maneuvered together with intermediate stage 110 by maneuvering means 122).

[0124] The terms 'stationary' and 'movable' as used herein with respect to the stationary input metal reservoir 106, intermediate stages 108 and 110, and two deposition modules 112 and 114, are construed to describe the manner of operation of these elements for metal deposition during additive casting. For example, the stationary input metal reservoir 106 may be movable for input metal replenish. For example, the stationary input metal reservoir 106 may independently maneuver, or be rolled or lifted out of its place by another unit (not shown), refilled with input metal and returned to its place. The term "movable" as used herein denotes that the intermediate stages 108 and 110 travel to and from the stationary input metal reservoir 106 for metal replenish.

[0125] The three tiers differ from each other in their metal input replenishment regime. To illustrate, using a simplified, non-limiting example, for the production of 500Kg. of gray iron per day using lOKg. rods as input metal, the stationary input metal reservoir may be construed to store several tens to hundreds metal rods and be replenished once a day, or once in a few days. During casting, the intermediate stage may carry a single rod, two, four, or six rods (carry 10-60 Kg.) and may travel from a deposition location to the stationary input metal reservoir every 0.5-3 hours, while the metal input to the deposition module may be provided every 0.25 to 1.5 hours, depending on the specific system configuration. The deposition module travels over the build plane in a deposition path predefined by a building plan. The deposition module may travel over the build table for metal refill, or stay on the deposition path and be served by the intermediate stage. Both the intermediate stage and the deposition module travel away from the build table after completing the fabrication of the object region in a production layer, for example, during mold region construction of the next production layer. Accordingly, metal conveyance considerations, for example, weight, accuracy, repeatability, efficiency, safety, timing, and production throughput are relevant for designing the metal deposition system configuration and its operation.

[0126] Each tier may include a single tier-component or a multiplicity of tiercomponents. For example, the first tier (tier 1) may include one or more stationary input metal reservoirs - a single tier component is shown in Fig. 1, serving both build tables. The transferring tier (tier 2) may include one or more intermediate stages (a single tier 2 component per build table is shown in Fig. 1, but this is not necessarily so), and the deposition tier (tier 3) may include one or more deposition modules (a single tier 3 component per build table is shown in Fig. 1, but this is not necessarily so).

[0127] Accordingly, each single tier component can serve or be served by more than one component of another tier. For example, a stationary input metal reservoir can serve several intermediate stages, a intermediate stage can receive movable metal doses from several stationary input metal reservoirs and can serve to deliver deposition-session doses to several deposition modules, and a deposition module can by served by receiving deposition-session doses from several intermediate stages. An exemplary system may feature a single stationary input metal reservoir, which can serve two intermediate stages (allocating and delivering a metal dose to one intermediate stage at the time, or to both at once), which serve the same deposition module (e.g., by alternately swapping places to shuttle metal thereto) or which serve two distinct deposition modules (e.g., each intermediate stage serves a single deposition module).

[0128] In one embodiment, two intermediate stages / intermediate stages which serve the same deposition module may contain different metals. Alternatively, in one embodiment, a single intermediate stage / intermediate stage can be configured to contain more than one metal, where the metals are different.

[0129] For example, the metals may differ in their type, chemical composition, metallurgical properties, mechanical properties, or other properties. The building plan may specify the locations at which specific metals with desired properties may be deposited. Thus, embodiments of the disclosure enable the manufacturing of cast with locally-controlled metal properties.

[0130] With reference to Figure 2, there is shown a metal system arrangement 200 which exemplify several options for implementing embodiments constructed and operative in accordance with the invention. The metal system arrangement 200 includes stationary input metal-dose reservoirs 202a and 202b in Tier 1, intermediate stages 204a - 204h in Tier 2, and deposition modules 206a - 206j (Tiers 2 and 3 are each represented by two respective rectangles only for the sake of convenience of demonstration). Some intermediate stages are served (or fed) by a single stationary input metal reservoir and some by two stationary input metal reservoirs. Some intermediate stages serve (or feed) a single deposition module and some serve more than one deposition module. Some deposition modules are served by a single intermediate stage and some are served by more than one intermediate stage. As exemplified, deposition module 206a is served by intermediate stage 204a which also serves deposition module 206b, which is also served by intermediate stage 204b, which also serves deposition module 206c, while both intermediate stages are fed from stationary metal-dose reservoir 202a. Intermediate stage 204c is served by stationary input metal-dose reservoirs 202a and 202b, and serves deposition modules 206d and 206e. Accordingly, intermediate stages 204a, 204b and 204c can be swapped in turns to receive service from stationary metal-dose reservoir 202a, and intermediate stages 204a and 204b can be swapped in turns to serve deposition module 206b. Intermediate stage 204d is fed by stationary metal-dose reservoir 202b and feeds deposition modules 206f and 206g. Intermediate stages 204e and 204f are fed by stationary metal-dose reservoir 202a and feed a single deposition module 206h, such as by cyclic swap of places for shuttling metal doses in turns between stationary metal-dose reservoir 202a and deposition module 206h. Intermediate stages 204g is fed by stationary metal-dose reservoirs 202a and 202b and feed a single deposition module 206i. Intermediate stage 204h is fed by stationary metal-dose reservoir 202b and feed a single deposition module 206j which is encased together with intermediate stage 204h in a single encasing 208.

[0131] The stationary input metal reservoir can contain large amounts of metal - at the order of tens and hundreds of kilograms, up to 1, 2 tons and more. Moving thereof is required for metal replenish - no moving thereof is required during production. In some cases, no heating of the entire metal is required. The intermediate stage is lightweight in comparison to the stationary input metal reservoir, by containing a smaller amount of metal dose, thereby saving heating energy resources required for retaining the metal in a molten state (e.g., 1150 degrees centigrade for Iron), as well as allowing fast and accurate maneuvering of a smaller dose, if required. The deposition module contains the smallest amount (a deposition-session dose) primarily for allowing fast and accurate maneuvering of the deposition means, and thereby also save heating energy resources required for bringing the molten metal into a casting-ready temperature (e.g., 1150- 1450-C for Iron, often 13005C).

[0132] For example, input metal in the amount of 200kg., 500Kg., 1 ton, 2 tons of metal may be handled by the first tier; the second tier - the metal-carrying movable tier, carry a smaller amount of metal between the first tier and the deposition module. For example, 5kg, 7Kg., 10Kg., 20Kg.2, 30Kg., 40Kg. of metal may be handled by the third tier; and the third tier - the deposition module - handles the smallest amount of metal, for example in a volume facilitating controllable heating and deposition and accurate positioning. For example, very small amounts of 5Ogr., lOOgr., 200 gr., 500 gr., and up to lkg., 2Kg., 5kg, 7Kg., lOKg. of metal may be handled by the third tier. The third tier may deposit metal at the pace or rate of up to lOcc / sec (or slower).

[0133] In some instances, wherein the intermediate stage is sufficiently small for fast maneuvering as required for deposition, the deposition module and the intermediate stage are physically coupled and movable together - thereby coupling tier 2 and tier 3 in a single movable unit. In other words, tiers 2 and 3 may be integrated.

[0134] In some embodiments, the deposition module may travel to the intermediate stage to receive molten metal from the intermediate stage.

[0135] The melting module, crucible, crucible cascade

[0136] In some embodiments, the stationary input metal reservoir is configured to receive solid input metal, e.g., in the form of rods, billets, pebbles, bars, ingots, scrap and the like.

[0137] The solid metal may be rationed and melted by a melting means (melting module) which is disposed in the stationary input metal reservoir, in the intermediate stage, or in the deposition module. The molten metal is retained in a crucible which is configured to contain and heat metal lingering therein in a molten state. This crucible can be respectively disposed downstream of the metal dripping from the melting means in the stationary input metal reservoir or in the intermediate stage.

[0138] For example, in accordance with some aspects of the invention utilizing metal rods as metal input, at least one of: the stationary input metal reservoir or the intermediate stage includes a melting module comprising a crucible configured to contain and heat metal lingering therein in a molten state, and a rod holder, a heater for heating e.g., a tip of the rod to drip molten metal into the crucible, and a rod feeder configured to feed solid metal to the melting module. The rod feeder may be configured to contain several rods (e.g., 1, 2, 3, 4 or more) and comprises a rod applicator configured to continuously feed the metal rods to the melting module for refilling.

[0139] A cascade of crucibles can be disposed in any of the tiers, i.e., a cascade of at least two crucibles in at least two corresponding tiers and / or a cascade of at least two crucibles in a single tier. Accordingly, if the solid metal is melted at the stationary input metal reservoir, the molten metal is dosed (as a 'movable dose'), allocated and delivered in a liquid state to the intermediate stage, from which a smaller portion ('depositionsession dose') of molten metal is dispensed to the deposition module. If the solid metal is melted at the intermediate stage, the solid input metal in the stationary input metal reservoir is dosed, allocated and delivered in a solid form movable dose to the intermediate stage, wherein the metal is eventually melted and from which a smaller portion of molten metal deposition-session dose is dispensed to the deposition module. In some embodiments, solid metal can be melted in the stationary input metal reservoir (stationary reservoirs 106, 202a-202b of Figures 1 and 2), or the intermediate stage (reservoirs 108, 110, 204a-204h of Figures 1 and 2). Accordingly, if melting is performed in the stationary input metal reservoir, molten metal doses are allocated to the intermediate stage (and molten metal is transferred to the deposition module). If melting takes place in the intermediate stage, solid metal is allocated from the stationary reservoir to the movable reservoir and the melting is performed before, during, or after metal doses are transported, before transferring molten metal to the deposition module. Reference is now made to Figure 3, which is a schematic illustration depicting an embodiment of a metal deposition system denoted 300, constructed and operative in accordance with the embodiment of the invention featuring a cascade of crucibles. System 300 features melting metal in tier 1 - the stationary input metal reservoir, thereby featuring a cascade of crucibles in all the tiers. However, optional melting in other tiers will also be described in conjunction with system 300.

[0140] System 300 includes stationary input metal reservoir 302, intermediate stage 304, and deposition module 306. Deposition module 306 may be coupled to and movable with intermediate stage 304 for example by sharing encasing 308. System 300 further includes controller 310, intermediate stage maneuvering means 312, deposition module maneuvering means 314 (which can be spared if deposition module 306 and intermediate stage 304 are coupled and movable together in encasing 308). System 300 may further include a working area heating unit 316 which is configured to heat previously-deposited metal 318 at a selected location, for example up to melting, thereby constituting a melt pool 320 ready to receive the deposited molten metal 356.

[0141] Stationary input metal reservoir 302 includes solid metal input 322 represented by a metal rod, and molten metal retainer 324. Stationary input metal reservoir 302 further includes melting means 326 (which can include resistive or inductive heating bodies) operational for melting the solid metal input 322, to drip to molten metal retainer 324, as denoted by drops 328, or to drip directly to intermediate stage 304, as denoted by drops 330, if stationary input metal reservoir 302 is devoid of molten metal retainer 324 (which is optional when no metal is retained in a molten state in stationary input metal reservoir 302).

[0142] It is noted that throughout the entire description herein, terms such as 'deposit', 'depositing', 'drip', 'dripping', 'drop' and the like, include any drizzle, trickle, flow, stream, release down, and the like, whether continuous or discrete, of molten metal which is deposited, released down or dropped to a lower location, whether a lower vessel or a lower casting location, are interchangeably used herein, irrespective of the discrete or continuous characteristic nature of the flow. In this context, the terms 'pace', 'rate' of such flow are similarly interchangeable and are applicable to evaluating the flux measure of any flow, drip, and the like, discrete or continuous.

[0143] Molten metal retainer 324 includes crucible 332, outlet 336 (which can be a release spout), and melt retaining heating means 338 (which can include resistive or inductive heating bodies) operational for keeping metal 334 in crucible 332 in a molten state, allowing metal 334 to drip through outlet 336, as denoted by drops 330, to intermediate stage 304. Dosage means such as a controllable plunger or selective solidifying-melting means (e.g., melting heaters for allowing flow, and solidifying coolers or additives for blocking passage, at outlet - not shown), can ration the dosage to be provided to intermediate stage 304. Alternatively, stationary input metal reservoir 302 merely includes solid metal input 322, without melting means 324, and a solid dosage allocator rations a solid metal dose which is cut away from solid metal input 322, and handed over to intermediate stage 304 (this alternative will be detailed further below).

[0144] Intermediate stage 304 is presented as a molten metal retainer featuring crucible 340, outlet 342 (which can be a release spout), and melt retaining heating means 344 (which can include resistive or inductive heating bodies) operational for keeping metal 346 in crucible 340 in a molten state, allowing metal 346 to drip through outlet 342, as denoted by drops 348, to deposition module 306. Intermediate stage 304 can also include optional solid metal dose-input (not shown), if metal is allocated in a solid form from stationary input metal reservoir 302. If intermediate stage 304 includes solidmetal dose-input, further optional melting means (not shown), operational for melting the solid metal dose-input, to drip to crucible 340, or to drip directly to deposition module 306, if intermediate stage 304 is devoid of crucible 340, as denoted by drops 348. Alternatively, intermediate stage 304 merely includes solid metal dose, without melting means, and a solid deposition-dosage allocator for rationing a solid metal depositiondose which is cut away from the solid metal dose, and handed over to deposition module 306 (this alternative will be detailed further below).

[0145] Intermediate stage maneuvering means 312 is operational for maneuvering intermediate stage 304 between stationary input metal reservoir 302 and deposition module 306. In case intermediate stage 304 and deposition module 306 are coupled in encasing 308, intermediate stage maneuvering means 312 is operational for maneuvering encasing 308 between stationary input metal reservoir 302 to selected locations of depositing (such as melt pool 320 in previously-deposited metal 318), wherein deposition module 306 deposits metal, and deposition module maneuvering means 314 is redundant and can be spared.

[0146] Deposition module 306 includes application depositor 350, and crucible 352.

[0147] In some embodiments, deposition module 306 can include merely one of these components: either application depositor 350, or crucible 352. Application depositor 350 receives molten metal either from crucible 352, as denoted by drops 354, or in the absence of crucible 352, molten metal as denoted by drops 348 directly from intermediate stage 304. Application depositor 350 is operational for heating molten metal into an additive-casting-temperature adequate for additive casting, and drip molten metal, as denoted by drops 356, to a selected location of depositing (working area), such as melt pool 320 in previously-deposited metal 318. Application depositor 350 may feature a transition section, implemented as a free passageway or with a flow restrictor operational for temporizing the drip of molten metal to linger for effective heating into an additive-casting-temperature adequate for additive casting. Accordingly, application depositor includes casting-ready heater 360 (which can be resistive or inductive), for heating the molten metal into an additive-casting-temperature adequate for additive casting. In the example of Figure 3, the Application depositor 350 is illustrated as a small-size crucible, however this is not necessarily so.

[0148] The application depositor 350 may be a crucible which is comprised in a crucible cascade. According to some embodiments, an application depositor 350 may be combined with a deposition module, in which solid material is melted, e.g. in which rods are melted for depositing the material.

[0149] The application depositor may be used for flow control, for example using a plunger, adjustment of composition, and / or adjustment of temperature, by an additional heating means. In an embodiment of the present invention, tier 3 may include a melting module which melts solid metal, a crucible which receives the melted metal, and an application depositor which receives melted metal from the crucible.

[0150] Crucible 352 includes outlet 362 (which can be a release spout), and melt retaining heating means 364 (which can include resistive or inductive heating bodies) operational for keeping metal 366 in crucible 352 in a molten state, allowing metal 366 to drip through outlet 362, as denoted by drops 354, to application depositor 350 or directly to a selected location of depositing, such as melt pool 320 in previously- deposited metal 318, as denoted by drops 356. Deposition module 306 can also include optional solid metal deposition-dose-input (not shown), if metal is allocated in a solid form from intermediate stage 304. If deposition module 306 includes solid-metal deposition-dose-input, further optional melting means (not shown), operational for melting the solid metal deposition-dose-input, to drip either to crucible 352, or to drip directly to application depositor 350, if deposition module 306 is devoid of crucible 352.

[0151] If deposition module 306 is devoid of application depositor 350, melt retaining heating means 364 are also operational for bringing metal 366 in crucible 352 into a casting-ready temperature, and outlet 362 is a release spout which can be controlled to selectively release metal 366 to trickle or drip through outlet 362 directly to melt pool 320, as denoted by drops 356.

[0152] Deposition module maneuvering means 314 (which can be spared if deposition module 306 and intermediate stage 304 are coupled and movable together in encasing 308 as described above), is operational for maneuvering deposition module 306 between stationary input metal reservoir 302 to selected locations of depositing (such as melt pool 320 in previously-deposited metal 318), wherein deposition module 306 deposits metal.

[0153] Controller 310 is connected at least to 302 intermediate stage 304 and deposition module 306 for controlling at least intermediate stage 304 and deposition module 306 for depositing the molten metal at a casting-ready temperature. Controller 310 can be connected to stationary input metal reservoir 302, as well as to further components such as intermediate stage maneuvering means 312, deposition module maneuvering means 314, working area heating unit 316, and any other components or sub-components of system 300 and its components. Accordingly, controller 310 can optionally control transporting speed of intermediate stage 304 by controlling deposition module maneuvering means 314, dose transferring pace / rate of molten metal to intermediate stage 304, deposition pace / rate of the deposition module 306, temperature of deposition module 306, and / or temperature of intermediate stage 304. Controller 310 can also be configured to control depositing of molten metal at a controlled pace / rate by controlling transporting speed of intermediate stage 304 and its metal dose application, dose transferring pace / rate of molten metal to intermediate stage 314, and / or deposition pace / rate of deposition module 306. Controller 310 can also be configured to control a start and a stop of deposition during additive metal casting by controlling molten metal dose transferring of intermediate stage 304, and / or molten metal deposition of deposition module 306.

[0154] It is noted that system 300 can include three crucibles, two crucible, or one crucible, as is demonstrated in the following options by tracking the storage locations and transfer of solid metal and molten metal in and between the three tiers:

[0155] (i) a 3-tier cascade of a serially reducing (size-wise) crucibles 332, 340, 352 wherein solid metal 322 is melted by melting means 326 at stationary input metal reservoir 302, and molten metal is stored in all three tiers and is initially transferred from stationary input metal reservoir 302 to intermediate stage 304, and then from intermediate stage 304 to deposition module 306;

[0156] (ii) a cascade of two consecutive crucibles 332 and 340 wherein solid metal is melted by melting means 326 at stationary input metal reservoir 302, molten metal is stored in the first two tiers and initially transferred from stationary input metal reservoir 302 to intermediate stage 304, and then transferred from intermediate stage 304 directly to application depositor 350 of deposition module 306;

[0157] (iii) a cascade of two consecutive crucibles 340 and 352, wherein solid metal is dispensed to and melted at intermediate stage 304, and molten metal is stored in the latter two tiers, initially stored in and transferred from intermediate stage 304, to deposition module 306;

[0158] (iv)a) a single crucible 340 wherein solid metal is dispensed to and melted at intermediate stage 304 where it is stored then transferred from intermediate stage 304 directly to application depositor 350 of deposition module 306; or, alternatively (iv)b) a single crucible 352 wherein solid metal is dispensed to movable metal-dose reservoir 304, and then is further dispensed in a solid form to deposition module 306, wherein the metal is melted and stored as molten state. It is noted that the structure of (iv) and (v) may be identical.

[0159] The inventors have realized that the cascade of two or more crucibles may be used for controlling the flow rate of the molten metal. If used in the second and / or third tier (deposition module), the cascade of two or more crucibles may be used for controlling the deposition rate or pace. This approach will be discussed with reference to Figures 4 and 5.

[0160] Figure 4 is a schematic cross-sectional illustration of a crucible 400 constructed and operative in accordance with the invention, featuring a plunger. Crucible 400 exemplify and can serve as any of crucibles 332 (including retainer 324), crucible 340 (including the housing of intermediate stage 304), or crucible 352, of the embodiment of Figure 3.

[0161] Crucible 400 includes ladle or crucible vessel 402, housing 404, drainage outlet orifice 406, and plunger 408. Molten metal 410 is contained in vessel 402. Bottom 414 of vessel 402 is slanting or tapering to allow effective drainage of molten metal 410 through outlet orifice 406, as a flow, trickle, or drip 415 of molten metal 410. Plunger 408 features a plunger rod 412 and bulbous head 417, and is configured to selectively block and unblock outlet orifice 406 when plunger 408 is lowered or elevated, respectively, and thereby function as a 'start-stop' valve, wherein a controller controls the elevation or lowering of plunger 408 by adequate lifting means (e.g., a motorized wheel to the circumference of which the upper end of plunger rod 412 is hinged and thereby lifted or lowered by a slight roll of the wheel about its axis). The gap between housing 404 and vessel 402 leaves space 416 in which heating elements 418 can be disposed for rendering and maintaining molten metal 410 in a molten state. Heating element 418 is presented as rounded cross-sections of a resistive or inductive electric wire wound around or about vessel 402, which is allow subtle control of accurate temperatures by a controller. However, use of indirect induction heating may also be achieved by embedding a conductive layer in the crucible wall.

[0162] Housing 404 provides isolation covering which retains the heat about the vessel 402, and provides a support for mounting heating elements 418. Heating elements 418 can be deployed about vessel 402 without housing 404, but would be requiring other supporting means for coupling to vessel 402. In the case of resistive heating, heat would dissipate without the isolating covering of housing 404, more energy would be required to be spent to reach and maintain the required temperature within vessel 402.

[0163] Accordingly, crucible 400 can be implemented as any crucible of the invention by virtue of controlling its movement, its dynamic heating (by heating element 418) and its start-stop mechanism (by lifting and lowering plunger 408).

[0164] The flow rate of a melt through the orifice is a function of the height of the melt reservoir in the crucible. By maintaining the height of the melt in the crucible, for example by monitoring the melt level and adjusting it by supplying melt from a higher tier unit or a buffer crucible, the flow rate may be controlled, and more specifically kept constant. Accordingly, a crucible cascade may be used for controlling the flow rate of the third tier crucible by controlling the height of molten metal in an upstream crucible. For example, if a small crucible containing, e.g., 50gr., lOOgr., 250 gr. of molten metal is used as the end crucible, height measurements in such a small crucible placed so closed to the deposition locations and, e.g., in eth presence of area heaters, may pose challenges. The inventors have realized that the flow rate of molten metal out of the end crucible may be controlled by controlling the molten metal height in an upstream crucible.

[0165] Reference is now made to Figure 5 which demonstrates a crucible cascade 500 that can be used for deposition flow rate control. Element 500A represents a source of molten metal - e.g., another crucible or metal rod, dripping molten metal into crucible 500B. Crucible 500B may be similar to crucible 400 shown in Figure 4, with controllable melt level and melt temperature, and optionally with controllable plunger rod for start / stop control. Crucible 500C receives molten metal from crucible 500B and release it on deposition location DL. The deposition flow rate Q of crucible 500C is equal to the flow rate of the melt from crucible 500B to crucible 500C. The flow rate of the melt from crucible 500B to crucible 500C is controlled by monitoring the melt level height h in crucible 500B and maintaining constant melt level height h by controlling the dripping of molten metal from source 500A to crucible 500B.

[0166] In the embodiment shown in Fig. 5, crucible 500B is a bottom pouring crucible with a plunger. The plunger may be controlled for deposition start and stop. Note that the start / stop mechanism illustrated in Fig. 5 may facilitate the control of deposition start / stop at the third tier as well as at a higher tier. The invention is not limited by the deposition start and stop mechanism that is used.

[0167] Metal rods as input

[0168] For ease of explanation, the principles of the invention will now be detailed with respect to Figures 6A-6B, 7A-7D, 8A-8B showing specific but non-limiting embodiments of metal deposition systems employing metal rods as input. Bars, Billets, wires, and any other metal piece with predetermined weight, size, shape and metal properties (microstructure and other metallurgical properties, mechanical properties, chemical properties) are equally suitable.

[0169] Metal deposition system 700A employs melting at tier 1 (Fig. 7A); metal deposition system 700C employs melting at tier 2 (Fig. 7C); metal deposition system 700D illustrates the use of a buffer crucible and a crucible cascade. Figures 6A-6B illustrate a rod manipulator that can be used with the systems illustrated in Figures 7A-7D.

[0170] Rod load manipulator: Reference is now made to Figures 6A-6B showing an exemplary rod manipulator that can be used with any of tier 1, 2 and 3. For example, rod load manipulator 724 may be used in system 700A (shown in Fig.7A) , operational for advancing (to the right) a horizontally disposed metal rod 723 which is uploaded as a single portion or is continuously fed by carriage 725 which supports rod 723 together with stationary rod supports 728. Load manipulator 724 comprises vertical metal drip chute 727 and rod melting coil 726.1, which is juxtaposed with supports 728 for melting metal at tip 732 of metal rod 723, whose molten drops drip through chute 727 to a crucible (not shown in Fig. 6A), when placed under crucible engagement plate 733 to receive the dripping metal. Additional heating e.g., by coil 726.2 may be provided.

[0171] As tip 732 of metal rod 723 gradually shortens by virtue of its melting, carriage 725, which is supported by and movable along guiding rail 730, advances, by an advancing and retracting mechanism along guiding rail 730 to keep tip 732 of the gradually shortening rod 723 due to melting of its tip 732, proximate to coil 726. When rod 723 is consumed, carriage 723 retracts to receive a fresh a refill of a new rod 723. If rod 723 leaves any remains (e.g., a rod portion below a predetermined length, the rod remains are retracted by carriage 723 and removed.

[0172] Melting at tier 1, crucible swap: In Figure 7A, there is shown metal deposition system 700A comprising a stationary input metal reservoir 701A and a single intermediate stage 702A (crucible 702A) in proximity to stationary input metal reservoir 701 for molten metal replenishment. Stationary input metal reservoir 701A includes metal rod reservoir 722. The cross section of four rods is illustrated for simplicity. Tens and hundreds of metal rods may be accommodated by stationary input metal reservoir 701A. Further illustrated are rod load manipulator 724, and melting module 704A showing rod 723 in a melting position, to be melted by rod melting coil 726. In operation, a single metal rod 723 is placed by rod load manipulator 724 near rod melting coil 726. Upon activation of the rod melting coil 726, the tip of rod 723 is heated and molten metal drips into crucible 702A. The displacement of rod 723 relative to crucible 702A may be adjusted along the melting of rod 723 by height adjusting means (not shown) configured for lowering rod 723 toward crucible 702A, lifting crucible 702A toward rod 723 or both.

[0173] Intermediate stage 702A may be a plunger-based intermediate stage as illustrated in Figure 4, but this is not necessarily so. Intermediate stage 702A may include crucible 704 which contains molten metal 710, outlet 706, plunger 708, melting heating element 718, valve heating element 719, and pressure adjusting means. A controller of system 700 (not shown) controls the lifting of plunger 708 to block and unblock outlet 706 as an on-off valve, melting heating element 718 for retaining metal 710 in a molten state, valve heating element 719 for further heating of metal 710 either for facilitating drip through outlet 706 or for a casting ready temperature for additive casting (directly on the casting location or through a further deposition module). The controller of system

[0174] 700 (not shown) may further control rod load manipulator 724 to control rod feed, and rod melting coil 726 to control melting rod power.

[0175] In another example (not shown), intermediate stages 702A.1, 702A.2 are designed as part of a series of disposable similar intermediate stages 702A (not shown), wherein each is employed once as a one-time expandable implement (or which is reusable in a later process after a recycling treatment).

[0176] Accordingly, system 700A, allows controllable deposition by a currently deployed (first) intermediate stage 702A.1 which engages stationary input metal reservoir 701 for receiving a dose of molten metal dripping from metal rod 722, and then move to a casting location for depositing metal (not shown) while another (second) intermediate stage 702A.2 is returning to engage with stationary input metal reservoir

[0177] 701 for receiving a dose of molten metal. The currently deployed intermediate stage 702A.1 swaps places with the returning intermediate stage 702A.2 for metal refill.

[0178] Melting at tier 2, crucible swap: figure 7C shows a metal deposition system 700C comprising a stationary input metal reservoir 701C, a single intermediate stage 702C (rod fetcher and melter) in proximity to stationary input metal reservoir 701C for rod replenishment. System 700C may comprise components similar to those of systems 700A, 700B and which similarly operates - although assigned to different tiers - thus are presented with similar numbering, stationary input metal reservoir 701C may be similar to stationary input metal reservoir 701B shown in Figure 7B. Rod load manipulator 724 is installed in intermediate stage 702C. Melting module 704B is installed in intermediate stage 702C. Metal deposition system 700C further comprises a deposition module 703C configured for receiving molten metal from intermediate stage 702C: molten metal is lingering into a crucible 720, to be deposited in the deposition locations (not shown).

[0179] In some embodiments, two or more deposition module 703C are employed (not shown in Figure 7C). While a first deposition module 703C is discharging molten metal in designated deposition locations, the intermediate stage 702C engages with a second deposition module 703C and fill it with molten metal to thereby prepare the molten metal for deposition in deposition locations designated to the second deposition module 703C.

[0180] Upon allocating all of the 4 metal rods 722, the intermediate stage 702B may return to stationary input metal reservoir 701B for rod magazine refill.

[0181] Figure 7D shows a metal deposition system 750 which may be similar to either of systems 700A-700C shown in Figures 7A-7C, to which an additional "buffer" crucible 752 is implemented downstream of melting module. The additional buffer crucible may be implemented as part of tier 1, tier 2 and tier, depending on the tier accommodating the melting module. The assignment of the various components to the architectural tiers is not shown in Figure 7D.

[0182] In addition, system 750 shows two crucibles that are installed in the deposition module: deposition crucible 754 in fluid connection with a small deposition crucible 756 , to thereby feature a three-crucible cascade (of crucibles 752, 704 and 756).

[0183] The buffer crucible 752 or the crucible cascade configuration may be used for several functions, including, but not limited to metallurgical processing of the molten metal, such as ensuring the same melting time and same heating profile for all of the input rods; proper addition of additives and inoculants (addition of additives and inoculants may be implemented in any of the other crucibles); dynamically enlarge or reduce the volume of molten metal ready for deposition, for example, as explained with reference to Fig. 5; and the like.

[0184] A series of crucibles 753 may be used (crucible swap) to thereby increase the overall deposition throughput, parallel deposition may also be facilitated, contributing to increased deposition throughput.

[0185] In the specific examples illustrated in Figures 7A-7D and in other implementations of the principles of the present disclosure, controllable deposition of molten metal for additive metal casting: in each of the architectural tiers, the volume allocated, the melting process, target temperatures can be controlled, to thereby ensure repeatability and successful industrial scaling.

[0186] The embodiments disclosed with reference to Figures 7A-7D exemplifies the use of metal rods as the solid metal input. The present disclosure is not limited by the type of metal used. Further, the solid input metal in stationary input metal reservoir can be allocated in any suitable form which meets the processing and melting capabilities and requirements of the intermediate stage. For example, rod portion(s), metal bars or metal gravel for other solid metal melting means.

[0187] Working area heating

[0188] The deposition module (element 703 shown in Figures 7A-7D, integrated system 800-I - with or without a buffer crucible as discussed with reference to Figure 8), is positioned in proximity to working areas - the areas on which the molten metal is to be deposited (areas 850 shown in Figure 8A). In some embodiments, additional heaters - working area heaters 860 shown in Figure 8B may be provided. Working area heaters 860 may provide heating to the deposition locations (working areas 850) - for example, pre-deposition heater / s, area deposition heater / s and / or post-deposition heater / s may be placed in proximity to the working areas 850, for providing pre-deposition heating, during-deposition heating and / or post-deposition heating of the working areas. In some embodiments, the working area heater / s may be physically and / or operably coupled to the deposition module. For example, with reference to Figures 7A-7D, the area heart / s may be carried by the travel unit that moves the deposition module over the build plane. With reference to Figure 8A, area heaters 860 may be carried by frame and shared travel module 824. In another example, the controllerthat controls the deposition temperature may further controls the operation of the working area heater / s such that the control of the molten metal upon deposition will reflect all the heat sources residing in proximity to the working areas and the molten metal drops (or stream) upon deposition.

[0189] In accordance with some aspects of the invention, the working area heater / s includes at least one heating element encircling the deposition module over the build plane (this is shown in Figure 8B). In accordance with some aspects of the invention, the heating elements can be rotated about the deposition module.

[0190] Controller and Sensors

[0191] In accordance with some aspects of the invention, the controller, such as controller 116 (shown in Fig. 1) or 310 (shown in Fig. 3) or the system controllers discussed with reference to Figs. 7A-7D, controls one or more parameters selected from the list including: transport speed of the intermediate stage, travel speed of deposition module, movable-dose transferring rate to the intermediate stage, deposition-session dose transferring rate to the deposition module, melting rate of the melting module deposition rate of the deposition module, temperature of the metal in the deposition module, temperature of the metal in the intermediate stage, deposition progress along a deposition path over the build plane, and distance between adjacent deposition path lines over the build plane.

[0192] In accordance with some aspects of the invention, the controller is configured to control depositing of the molten metal at a controlled rate, by controlling one or more of: transporting speed of the intermediate stage, dose transferring rate of the molten metal to the intermediate stage, and deposition rate of the deposition module.

[0193] In accordance with some aspects of the invention, the controller is configured to control a start and a stop of deposition during additive metal casting by controlling one or more of: molten metal dose transferring by the intermediate stage, and molten metal deposition by the deposition module.

[0194] In accordance with some aspects of the invention, the molten-metal deposition system further includes sensors, indicative of at least one parameter selected from the group of: temperature of molten metal incoming to a descent path in the deposition module, temperature of molten metal outgoing from the descent path right before depositing in the build plane, volume or flow rate of molten metal incoming to the descent path (e.g., a drip counter, width of stream detector), volume or flow rate of molten metal outgoing from the descent path (e.g., a drip counter, width of stream detector), and liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0195] Metal deposition methods

[0196] In accordance with the invention there are provided metal deposition methods that are implemented by a three-tier metal deposition system as described with reference to Figs. 1 to 8.

[0197] In some embodiments, illustrated in Fig. 9A, the metal deposition method 900A for additive casting, comprises the operations of:

[0198] In operation 902A: allocating movable-doses of metal contained in a stationary input metal reservoir to a intermediate stage and receiving a movable-dose in the intermediate stage. In operation 904A: conveying, by the intermediate stage, the movable-dose over one or more build tables. In operation 906A: transferring a deposition-session dose of metal from the intermediate stage to a deposition module and receiving the deposition-session dose in the deposition module. In operation 908A: melting, by a melting module, the metal in at least one of: the stationary input metal reservoir or the intermediate stage. In operation 910A: depositing, by the deposition module, the metal in a form of molten metal at casting-ready temperature in selected locations in the one or more build tables; and in operation 912A: controlling, by a controller, at least the intermediate stage and the deposition module for depositing the molten metal at a casting-ready temperature. Method 900A may further comprise operation 914A of containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of the stationary input metal reservoir, the intermediate stage; and the deposition module.

[0199] In some embodiments, illustrated in Fig. 9B, the metal deposition method 900B for additive casting, comprises the operations of:

[0200] A metal deposition method for additive casting, comprising the operations of: In operation 902B: allocating movable-doses of metal contained in a stationary input metal reservoir to a intermediate stage and receiving a movable-dose in the intermediate stage. In operation 904B: conveying, by the intermediate stage, the movable-dose over one or more build tables. In operation 906B: receiving metal from the intermediate stage and depositing molten metal. In operation 908B: depositing, by the deposition module, the metal in a form of molten metal at s deposition temperature in selected deposition locations in the one or more build tables. In operation 910B: controlling, by a controller, at least the one or more stationary input metal reservoirs, the intermediate stage, the deposition module and the one or more travel modules for preparing the input metal for deposition, wherein preparing the input metal for deposition comprises at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform at least one of the positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate.

[0201] In some embodiments, if the input metal is in solid state, method 900B further comprise operation 912B of melting, by a melting module, the metal in at least one of: the stationary input metal reservoir or the intermediate stage.

[0202] In some embodiments, preparing the input metal for deposition further comprises operation 914B of adjusting material properties by an inoculation mechanism in at least one of the one or more stationary input metal reservoir, the one or more intermediate stages, and the one or more deposition modules, and configured to add inoculants to the molten metal.

[0203] In each of metal deposition methods 900A and 900B, the operation of controlling may comprise controlling one or more parameters from the list of:

[0204] (a) transport speed of the intermediate stage;

[0205] (b) travel speed of deposition module;

[0206] (c) movable-dose transferring rate to the intermediate stage; (d) deposition-session dose transferring rate to the deposition module;

[0207] (e) melting rate of the melting module;

[0208] (f) deposition rate of the deposition module;

[0209] (g) temperature of the metal in the deposition module;

[0210] (h) temperature of the metal in the intermediate stage;

[0211] (i) deposition progress along a deposition path over the build plane; and

[0212] (j) distance between adjacent deposition path lines over the build plane.

[0213] In some embodiments the operation of controlling may comprise controlling the rate of depositing molten metal by controlling one or more of:

[0214] (i) transporting speed of the intermediate stage;

[0215] (ii) dose transferring rate of the molten metal to the intermediate stage; and

[0216] (iii) deposition rate of the deposition module.

[0217] In some embodiments the operation of controlling includes controlling a start and a stop of deposition during additive metal casting by controlling one or more of:

[0218] (i) molten metal dose transferring by the intermediate stage; and

[0219] (ii) molten metal deposition by the deposition module.

[0220] In some embodiments the operation of controlling includes controlling one or more of the parameters from the group of:

[0221] (i) temperature of molten metal incoming to a vertical shaft in the deposition module; (ii) temperature of molten metal outgoing from the vertical shaft in the deposition module right before depositing in the build plane;

[0222] (iii) volume orflow rate of molten metal outgoing from the melting module [drip counter, width of stream]; and

[0223] (iv) liquid height of molten metal in a crucible or pool, in response to readings of at least one of the parameters by a sensor which is indicative of the respective parameter.

[0224] Fig. 10 is a block diagram of a casting system 1000 that incorporates a metal deposition system 1002 according to embodiments of the invention, for example, as shown and discussed with reference to Figs. 1-8. Metal deposition system controller 1004 is incorporated with, hosted by or in data communication with casting system controller 1006.

[0225] Casting system 1000 further comprise mold construction system 1008. The operation of the mold construction system 1008 to layer-by-layer form the mold is properly synchronized with operational cycles of the metal deposition system 1002 (via communication of mold construction system controller 1010 with the metal deposition system controller 1004) to additively create production layers PL, each including metal in an object region 1016 surrounded by a mold region 1014. It should be understood that the object design defines the number of object regions surrounded by the respective mold regions, the number of production layers PL and additional parameters.

[0226] Mold construction of the mold regions 1014 in each production layer PL (and thus the entire mold structure build on the build table 1012 successively with the object structure) can be performed using in-situ and ex-situ construction process. In some embodiments of the in-situ process, the mold region(s) of each production layer is / are constructed within the common production environment (e.g., a production chamber encompassing build table 1012 or parts thereof) with the object region(s) of the same production layer, and the mold material being deposited is in a green-body state. For example, the in-situ process may utilize deposition of ceramic-based green-state paste. In another example, the in-situ process may utilize a binder jetting operation, i.e., using a mold powder provision device, a mold binder dispensing device and a mold powder removal device. In the ex-situ process, the mold construction unit forming the mold region is constructed in a separate production environment and is brought to the build table 1012 adjacent to that of the object region by a separate holding / translating unit (e.g., robot). For example, the ex-situ process may utilize a binder jetting operation, i.e., using a mold powder provision device, a mold binder dispensing device and a mold powder removal device. In another example, the ex-situ process may utilize a stack of frames, each containing a sand-based mold region with or without a replaceable pattern.

[0227] During operation, in a current production layer PL, metal deposition starts after mold construction systeml008 completes the construction of mold region 1014 of the current production layer PL. Metal system 1002 deposits molten metal on the object region defined by mold region 1014 and the previous production layer. Metal system 1002 deposits molten metal on selected deposition locations DL while traveling over build table 1012 along a deposition path DP. Before metal deposition, during metal deposition and / or after metal deposition, metal deposition system 1002 may further heats a working area WA near or around the- deposition location DL. Casting system 1000 is configured to carry out metal deposition methods implementing the three-tier architecture and metal deposition systems, for example, as discussed with reference to Figs. 9A-9C.

[0228] It will be appreciated by persons skilled in the art that the technique is not limited to what has been particularly shown and described hereinabove.

[0229] Several examples and embodiments of the present disclosure were disclosed herein and illustrated schematically. Components such as power supply, protective environment and shielding, motion elements, sensors, control lines and additional components are not shown for simplicity of explanation.

[0230] In the description and claims of the present application, each of the verbs, comprise," "include" and "have," and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of components, elements or parts of the subject or subjects of the verb.

[0231] As used throughout the specification, the terms "metal" or "metallic" refers to any metals and / or mellitic alloys which are suitable for melting and casting, for example, ferrous alloys, aluminum alloys, copper alloys, nickel alloys, magnesium alloys, and the like.

[0232] Any reference in the specification to a method should be applied mutatis mutandis to a system capable of executing the method and should be applied mutatis mutandis to a non-transitory computer-readable medium that stores instructions that, once executed by a computer, result in the execution of the method. Any reference in the specification to a system should be applied mutatis mutandis to a method that may be executed by the system and should be applied mutatis mutandis to a non-transitory computer-readable medium that stores instructions that may be executed by the system.

[0233] The terms "front," "back," "top," "bottom," "over," "under", and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the present disclosure described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0234] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of other elements or operations and stages than those listed in a claim. Furthermore, the terms "a" or "an," as used herein, are defined as one or more than one. Also, the use of introductory phrases such as "at least one" and "one or more" in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an." The same holds true for the use of definite articles. Unless stated otherwise, terms such as "first" and "second" are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

[0235] Description of embodiments of the invention in the present application are provided by way of example and are not intended to limit the scope of the invention. The described embodiments include different features, not all of which are required in all embodiments of the invention. Some embodiments utilize only some of the features or possible combinations of the features. Variations of embodiments of the invention that are described, and embodiments of the invention including different combinations of features noted in the described embodiments, will occur to persons of the art. The scope of the invention is limited only by the claims.

[0236] According to an aspect of the invention, there is provided a metal deposition system for molten-metal additive casting on one or more build tables, comprising

[0237] (a) one or more stationary input metal reservoirs configured to contain metal and allocate movable-doses of metal;

[0238] (b) one or more intermediate stages having at least an actuator configured to convey a movable-dose of metal allocated from the stationary reservoir;

[0239] (c) one or more deposition modules configured to receive a depositionsession dose of metal transferred from the intermediate stage and to deposit molten metal in selected locations in the one or more build tables;

[0240] (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more intermediate stages; and wherein at least one of: the one or more stationary input metal reservoir and the one or more intermediate stages comprises a melting module configured for melting the metal, and wherein the one or more deposition modules each comprises a crucible unit configured to contain and heat metal lingering therein in a molten state.

[0241] The metal deposition system according to the above aspect may further comprise a controller for controlling at least the one or more intermediate stages and the one or more deposition modules for depositing the molten metal at a casting-ready temperature.

[0242] In the metal deposition system according to the above aspects, the at least one of: the one or more stationary input metal reservoir and the one or more intermediate stages which comprises the melting module, may further comprise a solid metal feeder configured to feed solid metal to the melting module.

[0243] In the metal deposition system according to the above aspects, the crucible unit may comprise a crucible and a crucible heater for maintaining molten metal contained in the crucible at a desired temperature.

[0244] In the metal deposition system according to the above aspects, the crucible unit may be associated with a temperature sensor and the controller is responsive to readings of the temperature sensor for controlling the crucible heater.

[0245] In the metal deposition system according to the above aspects, the one or more stationary input metal reservoirs may comprise a solid input-metal feeder, the melting module, and a stationary molten metal crucible unit, wherein the one or more intermediate stages comprise a movable crucible unit for receiving the movable-doses as molten metal from the stationary input metal reservoir, and wherein the solid inputmetal feeder feeds solid input-metal to the melting module, the melting module melts the fed solid input metal into the stationary molten metal crucible unit, and the stationary molten metal crucible unit is configured to allocate the movable-doses of metal as molten metal to the movable crucible unit. In the metal deposition system according to the above aspects, the one or more stationary input metal reservoirs may comprise a solid input-metal feeder, and an input metal dosage allocator for allocating the movable-dose in the form of a soliddosage portion of input metal to the intermediate stage, and wherein the intermediate stage comprises a movable crucible unit and the melting module for melting and discharging molten metal from the solid dosage portion for discharging to the movable crucible unit.

[0246] The metal deposition system according to the above aspects may comprise a first build table, a second build table and a single stationary input metal reservoir, wherein the first build table is associated with a first one or more intermediate stages and a first one or more deposition modules, the second build table is associated with a second one or more intermediate stages and a second one or more deposition modules, and wherein the first one or more intermediate stages and the second one or more intermediate stages are configured to receive a respective movable-dose of metal allocated from the single stationary reservoir.

[0247] The metal deposition system according to the previous aspect may comprise a first build table, a second build table and a single stationary input metal reservoir, wherein each of the one or more intermediate stages and the one or more deposition modules is interchangeably operable over the first build table and the second build table.

[0248] In the metal deposition system according to the above aspects, the controller may controls one or more parameters selected from the list including:

[0249] (a) transport speed of the intermediate stage;

[0250] (b) travel speed of deposition module;

[0251] (c) movable-dose transferring rate to the intermediate stage;

[0252] (d) deposition-session dose transferring rate to the deposition module;

[0253] (e) melting rate of the melting module; (f) deposition rate of the deposition module;

[0254] (g) temperature of the metal in the deposition module;

[0255] (h) temperature of the metal in the intermediate stage;

[0256] (i) deposition progress along a deposition path over a build plane; and

[0257] (j) distance between adjacent deposition path lines over the build plane.

[0258] The metal deposition system according to the previous aspect may further comprise sensors, indicative of at least one parameter selected from the group consisting of:

[0259] (a) temperature of molten metal incoming to the deposition module;

[0260] (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane;

[0261] (c) volume or flow rate of molten metal incoming to the descent path;

[0262] (d) volume or flow rate of molten metal outgoing from the descent path; and

[0263] (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0264] In the metal deposition system according to the above aspects, preparing the input metal for deposition may comprise at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform the positioning, heating to a deposition temperature, and is optionally further configured to perform at least one of adjusting material properties, and setting a deposition rate, and wherein the input metal is in molten state and wherein the one or more stationary input metal reservoirs comprises heaters for retaining the input metal in molten state. According to an aspect of the invention, there is provided a casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; and the metal deposition system according to any one of claims 1 to 11, wherein the metal deposition system is operative to construct an object region of the current production layer; and wherein the one or more build tables are configured to support the vertical stack of production layers; and the controller is configured to control at least the mold construction system and the metal deposition system, and wherein the one or more intermediate stage is further configured to convey the movable-dose over a build plane, and to transfer deposition-session doses of metal from the movable-dose; the one or more deposition module is further configured to deposit metal in a form of molten metal in selected locations in the build plane; and the one or more travel modules are further configured to travel over the build plane at least one of: (1) the one or more deposition module; and (2) the one or more intermediate stage.

[0265] In the metal deposition system according to the previous aspect, at least one of the one or more stationary input metal reservoir, or the one or more intermediate stage, may further comprise a solid metal feeder configured to feed solid metal to the melting module.

[0266] According to an aspect of the invention, there is provided a metal deposition system for molten-metal additive casting on one or more build tables, comprising

[0267] (a) one or more stationary input metal reservoirs configured to contain input metal and allocate movable-doses of metal;

[0268] (b) one or more intermediate stages having at least an actuator configured to convey a movable-dose of metal allocated from the stationary reservoir;

[0269] (c) one or more deposition modules configured to receive metal from the intermediate stage and to deposit molten metal;

[0270] (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more intermediate stage; and

[0271] (e) a controller for controlling the one or more stationary input metal reservoirs, the one or more intermediate stages, the one or more deposition modules and the one or more travel modules for preparing the input metal for deposition, wherein preparing the input metal for deposition comprises at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform at least one of the positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate, and wherein the input metal is in molten state and wherein the one or more stationary input metal reservoirs comprises heaters for retaining the input metal in molten state.

[0272] In the metal deposition system according to the previous aspect, the one or more stationary input metal reservoirs may be configured to receive metal in the range of 200Kg. to 2000Kg, and / or the one or more intermediate stages may be configured to receive metal in the range of 5Kg. to 40Kg, and / or the one or more deposition modules may be configured to receive metal in the range of 0.05Kg. to lOKg, and / or one or more deposition modules may be configured to deposit metal in a deposition rate in the range of O.lcc / sec. to lOcc / sec.

[0273] In the metal deposition system according to the above aspects, one or more of the one or more stationary input metal reservoir, the one or more intermediate stages, and the one or more deposition modules, may comprise a material addition mechanism configured to add additives and inoculants to the molten metal for adjusting metal properties, wherein the material addition mechanism is incorporated in a buffer crucible.

[0274] In the metal deposition system according to the above aspects, the one or more deposition modules, may comprise a deposition crucible configured to deposit molten metal at a constant flow rate, wherein the deposition crucible receives metal from an upstream crucible associated with at least one of: the one or more stationary input metal reservoirs; the one or more intermediate stages; and the one or more deposition modules, and the controller is further configured to control the deposition flow rate by maintaining a fixed height of molten metal in the upstream crucible.

[0275] The metal deposition system of Claim 21 wherein the intermediate stage is configured for swapping with another intermediate stage.

[0276] In the metal deposition system according to the previous aspect, wherein at least the stationary input metal reservoirs and the one or more intermediate stages comprises a crucible swap station for swapping a crucible full of molten metal with a crucible depleted from molten metal, for refill.

[0277] In the metal deposition system according to the above aspects, a plurality of intermediate stages may be swapped in turns to receive a movable dose from the stationary metal-dose reservoir, and the intermediate stages can be swapped in turns to provide molten metal to the one or more deposition module. In the metal deposition system according to the above aspects, the controller may control one or more parameters selected from the list including:

[0278] (a) transport speed of the intermediate stage;

[0279] (b) travel speed of deposition module;

[0280] (c) movable-dose transferring rate to the intermediate stage;

[0281] (d) deposition-session dose transferring rate to the deposition module;

[0282] (e) melting rate of the melting module;

[0283] (f) deposition rate of the deposition module;

[0284] (g) temperature of the metal in the deposition module;

[0285] (h) temperature of the metal in the intermediate stage;

[0286] (i) deposition progress along a deposition path over the build plane;

[0287] (j) distance between adjacent deposition path lines over the build plane; and

[0288] (k) swapping of crucibles.

[0289] The metal deposition system according to the previous aspect may further comprise sensors, indicative of at least one parameter selected from the group consisting of:

[0290] (a) temperature of molten metal incoming to the deposition module;

[0291] (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane;

[0292] (c) volume or flow rate of molten metal incoming to the descent path;

[0293] (d) volume or flow rate of molten metal outgoing from the descent path; and

[0294] (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0295] Another aspect of the invention is a casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; and a controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system according to any of claims 15 to 26.

[0296] Another aspect of the invention is a metal deposition method for additive casting, comprising the operations of:

[0297] (a) allocating movable-doses of metal contained in a stationary input metal reservoir to a intermediate stages having at least an actuator and receiving a movable-dose in the intermediate stage;

[0298] (b) conveying, by the intermediate stage or a deposition module, the movable-dose over one or more build tables; (c) transferring a deposition-session dose of metal from the intermediate stage to the deposition module and receiving the deposition-session dose in the deposition module;

[0299] (d) melting, by a melting module, the metal in at least one of: the stationary input metal reservoir and the intermediate stage;

[0300] (e) depositing, by the deposition module, the metal in a form of molten metal at casting-ready temperature in selected locations in the one or more build tables; and

[0301] (f) controlling, by a controller, at least the intermediate stage and the deposition module for depositing the molten metal at a casting-ready temperature

[0302] (g) containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of:

[0303] (i) the stationary input metal reservoir;

[0304] (ii) the intermediate stage; and

[0305] (iii) the deposition module.

[0306] In the metal deposition system according to the above aspects, the may crucible comprise a controllable plunger.

[0307] In the metal deposition system according to the above aspects, the deposition module may be configured to deposit molten metal as a drip, drops, drizzle, trickle, flow, or stream.

[0308] In the metal deposition system according to the above aspects, a crucible cascade may be used for controlling a flow rate a crucible by controlling a height of molten metal in an upstream crucible.

[0309] In the metal deposition system according to the above aspects, the one or more intermediate stages, and optionally the one or more stationary input metal reservoirs, each comprises a crucible unit configured to contain and heat metal lingering therein in a molten state.

[0310] In the metal deposition system according to the above aspects, the one or more intermediate stages may further comprise one or more movable metal dose reservoirs.

[0311] In the present disclosure, various embodiments are described. Yet further embodiments, which are within the present disclosure are as follows:

[0312] Embodiment 1. A metal deposition system for molten-metal additive casting on one or more build tables, comprising (a) one or more stationary input metal reservoirs configured to contain metal and allocate movable-doses of metal; (b) one or more intermediate stages having at least an actuator configured to convey a movable-dose of metal allocated from the stationary reservoir; (c) one or more deposition modules configured to receive a deposition-session dose of metal transferred from the movable metal-dose reservoir and to deposit molten metal in selected locations in the one or more build tables; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more intermediate stages; and wherein at least one of: the one or more stationary input metal reservoir and the one or more intermediate stages comprises a melting module configured for melting the metal, and wherein the one or more deposition modules each comprises a crucible unit configured to contain and heat metal lingering therein in a molten state.

[0313] Embodiment 2. The metal deposition system according to embodiment 1, further comprising a controller for controlling at least the one or more intermediate stages and the one or more deposition modules for depositing the molten metal at a casting-ready temperature.

[0314] Embodiment 3. The metal deposition system of any of embodiments 1 or 2, wherein the at least one of: the one or more stationary input metal reservoir and the one or more intermediate stages which comprises the melting module, further comprises a solid metal feeder configured to feed solid metal to the melting module.

[0315] Embodiment 4. The metal deposition system according to any one of embodiments 1 to 3, wherein the crucible unit comprises a crucible and a crucible heater for maintaining molten metal contained in the crucible at a desired temperature.

[0316] Embodiment 5. The metal deposition system according to any one of embodiments 2 to 4, wherein the crucible unit is associated with a temperature sensor and the controller is responsive to readings of the temperature sensor for controlling the crucible heater.

[0317] Embodiment 6. The metal deposition system any one of embodiments 1 to 5, wherein the one or more stationary input metal reservoirs comprise a solid inputmetal feeder, the melting module, and a stationary molten metal crucible unit, wherein the one or more intermediate stages comprise a movable crucible unit for receiving the movable-doses as molten metal from the stationary input metal reservoir, and wherein the solid input-metal feeder feeds solid input-metal to the melting module, the melting module melts the fed solid input metal into the stationary molten metal crucible unit, and the stationary molten metal crucible unit is configured to allocate the movable-doses of metal as molten metal to the movable crucible unit.

[0318] Embodiment 7. The metal deposition system according to any one of embodiments 1 to 5, wherein the one or more stationary input metal reservoirs comprise a solid input-metal feeder, and an input metal dosage allocator for allocating the movable-dose in the form of a solid-dosage portion of input metal to the intermediate stage, and wherein the intermediate stage comprises a movable crucible unit and the melting module for melting and discharging molten metal from the solid dosage portion for discharging to the movable crucible unit.

[0319] Embodiment 8. The metal deposition system according to any one of embodiments 1 to 7, comprising a first build table, a second build table and a single stationary input metal reservoir, wherein the first build table is associated with a first one or more intermediate stages and a first one or more deposition modules, the second build table is associated with a second one or more intermediate stages and a second one or more deposition modules, and wherein the first one or more intermediate stages and the second one or more intermediate stages are configured to receive a respective movable-dose of metal allocated from the single stationary reservoir.

[0320] Embodiment 9. The metal deposition system of embodiment 8 comprising a first build table, a second build table and a single stationary input metal reservoir, wherein each of the one or more intermediate stages and the one or more deposition modules is interchangeably operable over the first build table and the second build table.

[0321] Embodiment 10. The metal deposition system according to any one of embodiments 2 to 9, wherein the controller controls one or more parameters selected from the list including: (a) transport speed of the intermediate stage; (b) travel speed of deposition module; (c) movable-dose transferring rate to the intermediate stage; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the intermediate stage; (i) deposition progress along a deposition path over a build plane (e.g., defined by at least one of the build tables); and (j) distance between adjacent deposition path lines over the build plane.

[0322] Embodiment 11. The metal deposition system of embodiment 10, further comprising sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0323] Embodiment 12. A metal deposition system according to any one of embodiments 1 to 11, wherein preparing the input metal for deposition comprises at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform the positioning, heating to a deposition temperature, and is optionally further configured to perform at least one of adjusting material properties, and setting a deposition rate, and wherein the input metal is in molten state and wherein the one or more stationary input metal reservoirs comprises heaters for retaining the input metal in molten state.

[0324] Embodiment 13. A casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; and the metal deposition system according to any one of embodiments 1 to 11, wherein the metal deposition system is operative to construct an object region of the current production layer; and wherein the one or more build tables are configured to support the vertical stack of production layers; and the controller is configured to control at least the mold construction system and the metal deposition system, and wherein the one or more intermediate stage is further configured to convey the movable-dose over a build plane (e.g., defined by at the build table), and to transfer deposition-session doses of metal from the movable-dose; the one or more deposition module is further configured to deposit metal in a form of molten metal in selected locations in the build plane; and the one or more travel modules are further configured to travel over the build plane at least one of: (1) the one or more deposition module; and (2) the one or more intermediate stage.

[0325] Embodiment 14. The casting system of Embodiment 13, wherein at least one of the one or more stationary input metal reservoir, or the one or more intermediate stage, further comprises a solid metal feeder configured to feed solid metal to the melting module. Embodiment 15. A metal deposition system for molten-metal additive casting on one or more build tables, comprising (a) one or more stationary input metal reservoirs configured to contain input metal and allocate movable-doses of metal; (b) one or more intermediate stages having at least an actuator configured to convey a movable-dose of metal allocated from the stationary reservoir; (c) one or more deposition modules configured to receive metal from the intermediate stage and to deposit molten metal; (d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more intermediate stage; and (e) a controller for controlling the one or more stationary input metal reservoirs, the one or more intermediate stages, the one or more deposition modules and the one or more travel modules for preparing the input metal for deposition, wherein preparing the input metal for deposition comprises at least one of: positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate and wherein the deposition module is configured to perform at least one of the positioning, heating to a deposition temperature, adjusting material properties, and setting a deposition rate, and wherein the input metal is in molten state and wherein the one or more stationary input metal reservoirs comprises heaters for retaining the input metal in molten state.

[0326] Embodiment 16. The metal deposition system of Embodiment 15, wherein the one or more stationary input metal reservoirs is configured to receive metal in the range of 200Kg. to 2000Kg.

[0327] Embodiment 17. The metal deposition system of Embodiment 15 or 16, wherein the one or more intermediate stages is configured to receive metal in the range of 5Kg. to 40Kg.

[0328] Embodiment 18. The metal deposition system according to any one of embodiments 15 to 17, wherein the one or more deposition modules is configured to receive metal in the range of 0.05Kg. to lOKg. Embodiment 19. The metal deposition system according to any one of embodiments 15 to 17, wherein the one or more deposition modules is configured to deposit metal in a deposition rate in the range of O.lcc / sec. to lOcc / sec.

[0329] Embodiment 20. The metal deposition system of any one of embodiments 15 to 19, wherein one or more of the one or more stationary input metal reservoir, the one or more intermediate stages, and the one or more deposition modules, comprises a material addition mechanism configured to add additives and inoculants to the molten metal for adjusting metal properties, and wherein the material addition mechanism is incorporated in a buffer crucible.

[0330] Embodiment 21. The metal deposition system according to any one of embodiments 15 to 20 wherein the one or more deposition modules, comprises a deposition crucible configured to deposit molten metal at a constant flow rate, wherein the deposition crucible receives metal from an upstream crucible associated with at least one of: the one or more stationary input metal reservoirs; the one or more intermediate stages; and the one or more deposition modules, and wherein the controller is further configured to control the deposition flow rate by maintaining a fixed height of molten metal in the upstream crucible.

[0331] Embodiment 22. The metal deposition system of any of embodiment 21 wherein the intermediate stage is configured for swapping with another intermediate stage.

[0332] Embodiment 23. The metal deposition system according to any one of embodiments 15 to 22, wherein at least the stationary input metal reservoirs and the one or more intermediate stages comprises a crucible swap station for swapping a crucible full of molten metal with a crucible depleted from molten metal, for refill.

[0333] Embodiment 24. The metal deposition system according to any one of embodiments 15 to 23 wherein a plurality of intermediate stages can be swapped in turns to receive a movable dose from the stationary metal-dose reservoir, and the intermediate stages can be swapped in turns to provide molten metal to the one or more deposition module.

[0334] Embodiment 25. The metal deposition system according to any one of embodiments 15 to 24, wherein the controller controls one or more parameters selected from the list including: (a) transport speed of the intermediate stage; (b) travel speed of deposition module; (c) movable-dose transferring rate to the intermediate stage; (d) deposition-session dose transferring rate to the deposition module; (e) melting rate of the melting module; (f) deposition rate of the deposition module; (g) temperature of the metal in the deposition module; (h) temperature of the metal in the intermediate stage; (i) deposition progress along a deposition path over the build plane; (j) distance between adjacent deposition path lines over the build plane; and (k) swapping of crucibles.

[0335] Embodiment 26. The metal deposition system of embodiment 25, further comprising sensors, indicative of at least one parameter selected from the group consisting of: (a) temperature of molten metal incoming to the deposition module; (b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane; (c) volume or flow rate of molten metal incoming to the descent path; (d) volume or flow rate of molten metal outgoing from the descent path; and (e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

[0336] Embodiment 27. A casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; and a controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system according to any of embodiments 15 to 26.

[0337] Embodiment 28. A metal deposition method for additive casting, comprising the operations of: (a) allocating movable-doses of metal contained in a stationary input metal reservoir to a intermediate stages having at least an actuator and receiving a movable-dose in the intermediate stage; (b) conveying, by the intermediate stage or a deposition module, the movable-dose over one or more build tables; (c) transferring a deposition-session dose of metal from the intermediate stage to the deposition module and receiving the deposition-session dose in the deposition module; (d) melting, by a melting module, the metal in at least one of: the stationary input metal reservoir and the intermediate stage; (e) depositing, by the deposition module, the metal in a form of molten metal at casting-ready temperature in selected locations in the one or more build tables; and (f) controlling, by a controller, at least the intermediate stage and the deposition module for depositing the molten metal at a casting-ready temperature (g) containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of: (i) the stationary input metal reservoir; (ii) the intermediate stage; and (iii) the deposition module.

[0338] Embodiment 29. The metal deposition system according to any one of embodiments 1 to 12, or 21 to 26, wherein the crucible comprises a controllable plunger.

[0339] Embodiment 30. A metal deposition system according to any one of embodiments 1 to 12 or 15 to 26, wherein the deposition module is configured to deposit molten metal as a drip, drops, drizzle, trickle, flow, or stream.

[0340] Embodiment 31. A metal deposition system according to any one of embodiments 1 to 12 or 15 to 26, wherein a crucible cascade is used for controlling a flow rate a crucible by controlling a height of molten metal in an upstream crucible.

[0341] Embodiment 32. A metal deposition system according to any one of embodiments 1 to 12, wherein the one or more intermediate stages, and optionally the one or more stationary input metal reservoirs, each comprises a crucible unit configured to contain and heat metal lingering therein in a molten state.

[0342] Embodiment 33. The metal deposition system according to any one of embodiments 1 to 12, wherein the one or more intermediate stages further comprise one or more movable metal dose reservoirs.

Claims

CLAIMS:

1. A metal deposition system for molten-metal additive casting on one or more build tables, comprising(a) one or more stationary input metal reservoirs configured to contain metal and allocate movable-doses of metal;(b) one or more movable metal-dose reservoirs configured to convey a movable-dose of metal allocated from the stationary reservoir;(c) one or more deposition modules configured to receive a depositionsession dose of metal transferred from the movable metal-dose reservoir and to deposit molten metal in selected locations in the one or more build tables;(d) one or more travel modules for traveling over the one or more build tables at least one of: (1) the one or more deposition modules; and (2) the one or more movable metal-dose reservoirs; and wherein at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoirs, and the one or more deposition modules, comprises a melting module configured for melting the metal.

2. The metal deposition system of Claim 1, further comprising a controller for controlling at least the one or more movable metal-dose reservoirs and the one or more deposition modules for depositing the molten metal at a casting-ready temperature.

3. The metal deposition system of Claim 1 or 2, wherein at least one of: the one or more stationary input metal reservoirs, the one or more movable metal-dose reservoirs, and the one or more deposition modules which comprises the melting module, further comprises a solid metal feeder configured to feed solid metal to the melting module.

4. The metal deposition system according to any one of claims 1 to 3, comprising a first build table, a second build table and a single stationary input metal reservoir, wherein the first build table is associated with a first one or more movable metal-dose reservoirs and a first one or more deposition modules, the second build table is associated with a second one or more movable metal-dose reservoirs and a second one or more deposition modules, and wherein the first one or more movable metal-dose reservoirs and the second one or more movable metal-dose reservoirs are configured to receive a respective movable-dose of metal allocated from a single stationary reservoir.

5. The metal deposition system of Claim 4 comprising a first build table, a second build table and a single stationary input metal reservoir, wherein each of the one or more movable metal-dose reservoirs and the one or more deposition modules is interchangeably operable over the first build table and the second build table.

6. The metal deposition system of any one of claims 2 to 5, wherein the controller controls one or more parameters selected from the list including:(a) transport speed of the movable metal-dose reservoir;(b) travel speed of deposition module;(c) movable-dose transferring rate to the movable metal-dose reservoir;(d) deposition-session dose transferring rate to the deposition module;(e) melting rate of the melting module;(f) deposition rate of the deposition module;(g) temperature of the metal in the deposition module;(h) temperature of the metal in the movable metal-dose reservoir;(i) deposition progress along a deposition path over a build plane; and(j) distance between adjacent deposition path lines over the build plane.

7. The metal deposition system of claim 6, further comprising sensors, indicative of at least one parameter selected from the group consisting of:(a) temperature of molten metal incoming to the deposition module;(b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane;(c) volume or flow rate of molten metal incoming to a descent path;(d) volume or flow rate of molten metal outgoing from the descent path; and(e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

8. The metal deposition system according to anyone of claims I to 7, wherein the one or more stationary input metal reservoirs is configured to receive metal in the range of 200Kg. to 2000Kg.

9. The metal deposition system according to any one of claims 1 to 7 or 8, wherein the one or more movable metal-dose reservoirs is configured to receive metal in the range of 5Kg. to 40Kg.

10. The metal deposition system according to any one of claims 1 to 7, 8 or 9, wherein the one or more deposition modules is configured to receive metal in the range of 0.05Kg. to lOKg.

11. The metal deposition system according to any one of claims 1 to 7, 8, 9 or 10, wherein the one or more deposition modules is configured to deposit metal in a deposition rate in the range of O.lcc / sec. to lOcc / sec.

12. The metal deposition system any one of claims 1 to 7, 8, 9, 10 or 11, wherein one or more of the one or more stationary input metal reservoirs, the one or more movable metal-dose reservoirs, and the one or more deposition modules, comprises an inoculation mechanism configured to add inoculants to the molten metal for adjusting metal properties.

13. The metal deposition system any one of claims 2 to 7, 8, 9, 10, 11 or 12, wherein the controller controls one or more parameters selected from the list including:(a) transport speed of the movable metal-dose reservoir;(b) travel speed of deposition module;(c) movable-dose transferring rate to the movable metal-dose reservoir;(d) deposition-session dose transferring rate to the deposition module;(e) melting rate of the melting module;(f) deposition rate of the deposition module;(g) temperature of the metal in the deposition module;(h) temperature of the metal in the movable metal-dose reservoir;(i) deposition progress along a deposition path over the build plane; and(j) distance between adjacent deposition path lines over the build plane.

14. The metal deposition system of claim 13, further comprising sensors, indicative of at least one parameter selected from the group consisting of:(a) temperature of molten metal incoming to the deposition module;(b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane;(c) volume or flow rate of molten metal incoming to a descent path;(d) volume or flow rate of molten metal outgoing from the descent path; and(e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

15. The metal deposition system according to any one of claims 1 to 7 or 8 to14, wherein the movable metal-dose reservoir is an intermediate stage configured to carry the movable metal dose, and having an actuator to move the metal-dose.

16. A metal deposition method for additive casting, comprising the operations of:(a) allocating movable-doses of metal contained in a stationary input metal reservoir to a movable metal-dose reservoir and receiving a movable-dose in the movable metal-dose reservoir;(b) conveying, by the movable metal-dose reservoir, the movable-dose over one or more build tables;(c) transferring a deposition-session dose of metal from the movable metal-dose reservoir to a deposition module and receiving the deposition-session dose in the deposition module;(d) melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module;(e) depositing, by the deposition module, the metal in a form of molten metal at casting-ready temperature in selected locations in the one or more build tables; and(f) controlling, by a controller, at least the movable metal-dose reservoir and the deposition module for depositing the molten metal at a casting-ready temperature.

17. The metal deposition method of claim 16, further comprising the operation of:(g) containing in a crucible and heating metal lingering therein in a molten state, wherein the crucible is disposed in at least one of:(i) the stationary input metal reservoir;(ii) the movable metal-dose reservoir; and(iii) the deposition module.

18. The metal deposition method of claim 16, wherein the input metal is in solid state and wherein preparing the metal for deposition further comprises melting, by a melting module, the metal in at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module.

19. The metal deposition method of claim 18, wherein preparing the input metal for deposition further comprises adjusting material properties by an inoculation mechanism in at least one of the one or more stationary input metal reservoirs, the one or more movable metal-dose reservoirs, and the one or more deposition modules, and configured to add inoculants to the molten metal.

20. The metal deposition method of claim 19, further comprising controlling, by the controller, one or more parameters selected from the list including:(a) transport speed of the movable metal-dose reservoir;(b) travel speed of deposition module;(c) movable-dose transferring rate to the movable metal-dose reservoir;(d) deposition-session dose transferring rate to the deposition module;(e) melting rate of the melting module;(f) deposition rate of the deposition module;(g) temperature of the metal in the deposition module;(h) temperature of the metal in the movable metal-dose reservoir;deposition progress along a deposition path over the build plane; and(j) distance between adjacent deposition path lines over the build plane.

21. The metal deposition method of claim 20, further comprising controlling one or more of the parameters, by a controller responsive to readings of sensors indicative of at least one parameter selected from the one or more of the parameters consisting of:(a) temperature of molten metal incoming to the deposition module;(b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane;(c) volume or flow rate of molten metal incoming to a descent path;(d) volume or flow rate of molten metal outgoing from the descent path; and(e) liquid height of molten metal in a crucible or pool.

22. A casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; anda controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system comprises(a) one or more stationary input metal reservoir configured to contain metal and allocate movable-doses of metal;(b) one or more movable metal-dose reservoir configured to convey the movable-dose over a build plane, and to transfer deposition-session doses of metal from the movable-dose;(c) one or more deposition module configured to receive a deposition-session dose of metal transferred from the movable metal-dose reservoir and to deposit metal in a form of molten metal in selected locations in the build plane; and(d) one or more travel modules for traveling over the build plane at least one of: (1) the one or more deposition module; and (2) the one or more movable metal-dose reservoir; and the controller is further to control at least the movable metal-dose reservoir and the deposition module for depositing the molten metal at a casting-ready temperature, wherein at least one of: the stationary input metal reservoir, the movable metal-dose reservoir, and the deposition module, comprises a melting module configured for melting the metal.

23. The casting system of claim 22, wherein the respective at least one of: the one or more stationary input metal reservoir, the one or more movable metal-dose reservoir, and the one or more deposition module which comprises the melting module,further comprises a solid metal feeder configured to feed solid metal to the melting module.

24. The casting system of claim 22, wherein the controller controls one or more parameters selected from the list including:(a) transport speed of the movable metal-dose reservoir;(b) travel speed of deposition module;(c) movable-dose transferring rate to the movable metal-dose reservoir;(d) deposition-session dose transferring rate to the deposition module;(e) melting rate of the melting module;(f) deposition rate of the deposition module;(g) temperature of the metal in the deposition module;(h) temperature of the metal in the movable metal-dose reservoir;(i) deposition progress along a deposition path over the build plane; and(j) distance between adjacent deposition path lines over the build plane.

25. The casting system of claim 24, further comprising sensors, indicative of at least one parameter selected from the group consisting of:(a) temperature of molten metal incoming to the deposition module;(b) temperature of molten metal outgoing from the deposition module right before depositing in the build plane;(c) volume or flow rate of molten metal incoming to a descent path;(d) volume or flow rate of molten metal outgoing from the descent path; and(e) liquid height of molten metal in a crucible or pool, wherein the controller is responsive to readings of the sensors for controlling one or more of the parameters.

26. A casting system for casting a metallic object by constructing a plurality of production layers forming a vertical stack, wherein production layers of the plurality have mold regions, wherein production layers of the plurality have object regions defined by the mold regions, and wherein a current production layer is constructed upon a top surface of a previous production layer of the vertical stack, the system comprising: a mold construction system operative to construct a mold region of the current production layer; a metal deposition system operative to construct an object region of the current production layer; a build table, for supporting the vertical stack of production layers; and a controller for controlling at least the mold construction system and the metal deposition system, wherein the metal deposition system is the metal deposition system according to any of claims 1 to 14.

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