Method and testing system for testing the mechanical integrity of a ceramic core for investment casting by changing viscosity

Abstract

Method for testing a ceramic core (112) used for investment casting, the method comprising: Positioning the ceramic core (112) inside a mold (110, 210) to receive a sacrificial fluid (284) in order to form a sacrificial material (130) on at least one section of the ceramic core (112), wherein the ceramic core (112) has a predefined layout; during the casting of the sacrificial fluid (284) around the ceramic core (112, 112A, 112B) using the mold (110, 210), controlling the viscosity of the sacrificial fluid (284) to simulate an expected viscosity of a molten metal used during a subsequent investment casting process using the ceramic core (112); and Evaluating mechanical damage to at least one area of ​​the ceramic core (112) caused by the pouring of the sacrificial fluid (284).

Description

BACKGROUND TO THE INVENTION

[0001] The disclosure relates generally to investment casting and in particular to a method and a testing system for testing the mechanical integrity of a core used for investment casting by changing viscosity.

[0002] Investment casting is used to manufacture a wide variety of industrial parts, such as turbomachinery turbine blades. An investment casting process uses a casting with a sacrificial pattern to form a ceramic mold for investment casting. Certain types of castings may contain a core or insert within the sacrificial pattern. The core defines the internal structure of the component and becomes part of the ceramic mold used during the investment casting process. The core can incorporate a wide variety of complex features that define the component's internal structure. Cores can be additively manufactured to enable rapid prototyping and core fabrication. The casting is produced by pouring a sacrificial fluid, such as hot wax or a polymer, around the core in a mold that defines the component's shape surrounding the core.The hardened copper material that forms around the core defines the shape of the component for investment casting.

[0003] Each casting, either individually or in a group, can be immersed in a slurry and coated with a ceramic to form a ceramic mold for investment casting. Once the sacrificial material is removed from the ceramic mold, it can be used to investment cast the component using molten metal, for example, after preheating the ceramic mold. Once the molten metal has solidified, the ceramic mold can be removed, and the core can be extracted using a leaching agent. The component can then be finished in a conventional manner, for example, by heat treatment and conventional finishing.

[0004] Investment casting is a time-consuming and expensive process, especially when components need to be manufactured to precise dimensions. Where exact dimensions are required, the formation of the casting must be highly accurate. Any mold used to create the casting can be very expensive and time-consuming to manufacture. Consequently, any changes to the core or the component can be very costly and time-consuming to address. Further challenges that can be costly and time-consuming to overcome include unforeseen weaknesses in the core, which can cause it to crack or break during the formation of the casting (e.g., during the pouring of sacrificial material around the core) or during the actual investment casting process.For example, a high-pressure sacrificial fluid injected into a mold around the core during casting can cause the core to crack or break, or molten metal injected during investment casting can lead to core cracking or breakage. In the former case, the core must be modified, and in the latter, the core and / or the mold for the casting may require modification. In either case, the changes are costly and time-consuming. Currently, there is no mechanism to proactively address the challenges associated with core cracking / breakage.

[0005] One approach to detecting duration and costs utilizes additive manufacturing of the cores and molds used to produce the casting. In particular, additive manufacturing allows for faster turnaround times for design changes to cores and / or the component leading to component manufacturing steps. Additive manufacturing (AM) encompasses a wide variety of processes for creating an object by successively layering material rather than removing it. Additive manufacturing can create complex geometries without the use of any kind of tooling, molds, or fixtures, and with little or no waste material. Instead of machine-making objects from solid blocks of material, much of which is cut away and discarded, the only material used in additive manufacturing is that required to shape the object.Current categories of additive manufacturing can include: Binder Jetting (3D powder printing with binder application), material extrusion, powder bed infusion (powder bed-based melting), directed energy deposition (directed energy input), layer lamination, and vat photopolymerization.

[0006] Additive manufacturing techniques typically involve using a three-dimensional (3D) computer-aided design (CAD) file of the object to be produced (e.g., a core and / or mold for a casting), electronically slicing the object into layers (e.g., with a thickness of 18–102 micrometers) to generate a file containing a two-dimensional image of each layer (including vectors, images, or coordinates) that can be used to manufacture the object. The 3D CAD file can be generated in any known way, e.g., by a computer-aided design (CAD) system, a 3D scanner, or digital photography and photogrammetry software. The 3D CAD file can undergo any necessary repairs to correct defects (e.g., holes, etc.) and can be in any CAD format, such as a Standard Tessellation Language (STL) file.The 3D CAD file can then be processed by a preparation software system (sometimes referred to as a "slicing machine") that interprets the 3D CAD file and electronically slices it so that the object can be built by various types of additive manufacturing systems. The object code file can be of any format compatible with the desired AM system. For example, the object code file can be an STL file or an additive manufacturing file (AMF), the latter being an international standard based on an extensible markup language (XML) designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be manufactured on any AM printer.Depending on the type of additive manufacturing used, material layers are selectively dispensed, sintered, formed, applied, etc., to create the object according to the object code file.

[0007] One form of powder bed fusion (referred to herein as metal powder-based additive manufacturing) can include direct metal laser melting (DMLM), also known as selective laser melting (SLM). This process is advantageous for creating metal shapes to form castings. In metal powder-based additive manufacturing, layers of metal powder are sequentially fused together to form the object. Specifically, fine layers of metal powder are melted successively after being evenly distributed on a metal powder bed using an applicator. Each applicator contains an applicator element in the form of a lip, brush, blade, or roller made of metal, plastic, ceramic, carbon fiber, or rubber, which evenly distributes the metal powder across the build platform.The metal powder bed can be moved along a vertical axis. The process takes place in a processing chamber with a precisely controlled atmosphere. Once each layer is created, each two-dimensional slice of the object's geometry can be fused by selectively melting the metal powder. Melting can be achieved using a powerful irradiation beam, such as a 100-watt ytterbium laser, to completely weld (melt) the metal powder to form a solid metal. The irradiation beam moves in the XY direction or is deflected in the XY direction and has sufficient intensity to completely weld (melt) the metal powder to form a solid metal. The metal powder bed can be lowered for each subsequent two-dimensional layer, and the process is repeated until the object is completely formed.To produce certain larger objects more quickly, some metal-based additive manufacturing systems use a pair of powerful lasers working together to form an object, such as a mold. Other additive manufacturing processes, such as 3D printing, can build layers by extruding material in layers.

[0008] Although additive manufacturing of cores and / or molds for casting reduces the time and cost of adapting cores and / or molds, challenges remain. In particular, current mold systems and practices for casting a single mold are independent of core variations. If core variations are subtle, or if the core has fine or intricate features, this can result in cracked or broken cores and / or inaccurate castings. If core variations are more pronounced, for example, if they share a common structure but also have another structure that varies significantly to build different components, each core variation must have its own mold. Current mold systems used to create castings are also not sufficiently thermally adaptable to accommodate the flow of sacrificial material over different cores.

[0009] Another challenge in current investment casting is ensuring that cores within a casting can withstand the actual investment casting process, i.e., pouring molten metal around the core. Current practice involves a trial-and-error approach, using a casting to perform an investment casting to determine its performance. During the investment casting process, the core may, for example, break, crack, or prevent sufficient molten metal flow to form the component. Lacking any mechanism to predict core performance, if a problem is identified during an investment casting, changes must be made to the core, the metal mold for the casting, and / or the casting formation process, all of which are time-consuming and costly. BRIEF DESCRIPTION OF THE INVENTION

[0010] A first aspect of the disclosure provides a method for testing a ceramic core used for investment casting. The method includes: positioning the ceramic core inside a mold to receive a sacrificial fluid in order to form a sacrificial material on at least one section of the ceramic core, the ceramic core having a predefined layout; during the pouring of the sacrificial fluid around the ceramic core using the mold, controlling the viscosity of the sacrificial fluid to simulate an expected viscosity of a molten metal used during a subsequent investment casting process using the ceramic core; and evaluating the mechanical damage to at least one area of ​​the ceramic core caused by the pouring of the sacrificial fluid.

[0011] In the aforementioned process, the mechanical damage can include tearing or breaking of the ceramic core.

[0012] Any of the aforementioned methods may, after evaluation, involve modifying the predefined layout of the ceramic core.

[0013] Additionally, the process may further involve repeating the positioning, controlling the viscosity, evaluating and modifying until the pouring of the sacrificial fluid does not damage the ceramic core.

[0014] In some preferred embodiments, any of the aforementioned methods may further comprise forming the shape by attaching several separable mold parts to one another.

[0015] In addition, the process can also include temperature control for each of the several separable molded parts.

[0016] Furthermore, at least one of the several separable molded parts may contain a heat-conducting channel which is arranged to guide a thermal fluid through it in order to control the temperature of the at least one of the several separable molded parts, wherein controlling the viscosity of the sacrificial fluid may include controlling the temperature of the at least one of the several separable molded parts by guiding the thermal fluid through the heat-conducting channel.

[0017] In any of the aforementioned preferred embodiments, the method may further comprise: heating several flows of the sacrificial material fluid to different temperatures in order to control the viscosity of each of the several flows of the sacrificial material; and directing each of the several flows of the sacrificial material fluid to a respective separable molded part of the several separable molded parts.

[0018] Additionally or as an alternative, the method may further comprise: heating several flows of the sacrificial fluid to different temperatures in order to control the viscosity of each of the several flows of the sacrificial fluid; and directing each of the several flows of the sacrificial fluid to a respective separable molded part of the several separable molded parts; wherein at least one of the several separable molded parts may further comprise a thermally conductive channel arranged to direct a thermal fluid through it in order to control the temperature of at least one of the several separable molded parts, wherein the control of the viscosity of the sacrificial fluid further comprises controlling the temperature of at least one of the several separable molded parts by directing the thermal fluid through the thermally conductive channel.

[0019] A second aspect of the disclosure provides a system for testing a ceramic core used for investment casting, comprising: a mold containing the ceramic core for receiving a sacrificial fluid to form a sacrificial material on at least one section of the ceramic core, the ceramic core having a predefined layout; a viscosity control system for controlling the viscosity of the sacrificial fluid during the casting of the sacrificial fluid around the ceramic core to simulate an expected viscosity of a metal melt used during a subsequent investment casting process using the ceramic core; and an evaluation system for assessing the ceramic core to detect any mechanical damage caused by the casting of the sacrificial fluid on at least one area of ​​the ceramic core.

[0020] In the previously mentioned testing system, mechanical damage can include tearing or breaking of the ceramic core.

[0021] In any of the aforementioned testing systems, the mold can contain two or more separable mold parts that are attached to one another.

[0022] Additionally, at least one of the separable molded parts can contain a heat-conducting channel arranged to guide a thermal fluid through it in order to control the temperature of the at least one separable molded part, wherein the viscosity control system can include a control for thermal fluid of the mold to control the temperature of the at least one separable molded part by guiding the thermal fluid through the heat-conducting channel.

[0023] Furthermore, or as an alternative, the test system may also include a sacrificial fluid heating system for heating several flows of the sacrificial fluid to different temperatures in order to control the viscosity of each of the several flows of the sacrificial material, and for directing each of the several flows of the sacrificial fluid to a respective separable mold part of the mold via at least one sacrificial fluid inlet.

[0024] In any of the aforementioned testing systems, the mold may contain several separable mold parts that can be joined together to create the mold and are configured to form the sacrificial material from the sacrificial fluid around the core, each of the several separable mold parts being able to contain at least one sacrificial fluid supply area.

[0025] A third aspect of the disclosure includes a method for testing a ceramic core used for investment casting, wherein the method comprises: positioning the ceramic core inside a mold to receive a sacrificial fluid in order to form a sacrificial material on at least one section of the ceramic core, the ceramic core having a predefined layout; and controlling the sacrificial fluid to simulate an expected viscosity of a metal melt used during a subsequent investment casting process using the ceramic core.

[0026] The procedure according to the third aspect may further include an assessment of any mechanical damage to the core caused by the sacrificial fluid, the assessment being carried out prior to the subsequent investment casting process.

[0027] Additionally, the process can also involve modifying the predefined layout of the ceramic core based on the evaluation.

[0028] The illustrative aspects of this revelation are intended to solve the problems described herein and / or other, unexplained problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and other features of this revelation will be more easily understood with the help of the following detailed description of the various aspects of the revelation in conjunction with the accompanying drawings, which show different embodiments of the revelation. Fig. Figure 1 shows a perspective front view of a form system according to embodiments of the disclosure, Fig. Figure 2 shows a perspective rear view of a form system according to embodiments of the disclosure. Fig. Figure 3 shows a transparent perspective front view of the mold system according to embodiments of the disclosure. Fig. Figure 4 shows a transparent perspective side view of the form system according to embodiments of the disclosure. Fig. Figures 5-7 show schematic side views of exemplary different cores. Fig. Figure 8 shows a schematic top view of exemplary superimposed different cores. Fig. Figure 9 shows a cross-sectional top view of a first core in a molding system containing separable molded parts, according to embodiments of the disclosure. Fig. Figure 10 shows a cross-sectional top view of a second, different core compared to the one shown after. Fig. 9 in a molding system comprising various separable molded parts, according to embodiments of the disclosure. Fig. Figures 11-14 show different views of a pair of separable mold parts of a molding system according to embodiments of the disclosure. Fig. Figures 15-18 show different views of another pair of separable mold parts of a molding system according to embodiments of the disclosure. Fig. Figure 19 shows a perspective view of an exemplary core positioning device according to an embodiment of the disclosure. Fig. Figure 20 shows a schematic cross-sectional view of an exemplary mold system comprising a thermal fluid control for the mold to supply a temperature-controlled thermal fluid to heat-conducting mold channels in the mold, and illustrating different heat-conducting mold channel paths and positions according to various embodiments of the disclosure. Fig. Figure 21 shows a schematic cross-sectional view of an exemplary mold system incorporating a sacrificial material heating system, according to various embodiments of the disclosure. Fig. Figure 22 shows a flowchart illustrating procedures according to different embodiments of the disclosure. Fig. 23 represents an investment casting process that includes a verification of the mechanical integrity of a ceramic core by changing viscosity, according to various embodiments of the disclosure. Fig. 24 presents a method for verifying the mechanical integrity of a ceramic core by changing viscosity according to various embodiments.

[0030] It should be noted that the drawings in Revelation are not necessarily to scale. The drawings are intended to represent typical aspects of Revelation and should therefore not be interpreted in a way that limits the scope of protection afforded by Revelation. Within the drawings, identical reference symbols represent identical elements among the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0031] As shown above, the disclosure provides a molding system that includes a mold to receive a selected core chosen from several different cores. The mold is configured to form a sacrificial material from a sacrificial fluid, such as wax or a polymer, around the selected core to produce a casting. The casting, including the core and the cured sacrificial fluid around it, is used in a conventional manner to form a ceramic mold for subsequent investment casting of a component. The different cores can differ from one another in various ways, such as shape, dimensions, contours, material properties, etc. In one example, each different core may have a similar shape but exhibit some dimensional variation.In another example, part of a mold for a casting can be used to form a number of components that share a common, primary internal structure formed by a common core, but contain a number of other, secondary internal structures formed by a second, different core. That is, the common, primary internal structure can be formed by a primary, common core, while the other, secondary internal structures can be created by different secondary cores. The cores can be made of ceramic or another refractory material (e.g., niobium, molybdenum, tantalum, tungsten, or rhenium), a metal, a metal alloy, or combinations thereof.

[0032] To overcome the challenge of different cores, a mold according to embodiments of the disclosure contains several separable mold parts that can be joined together to produce the mold. Unlike conventional mold systems, at least one selected separable mold part contains a set of different interchangeable variants of the at least one selected separable mold part. Each different interchangeable variant of the selected separable mold part is configured to accommodate a different core from the multiple different cores. In this way, variants of cores, whether simple dimensional differences or significantly different internal structures for producing different components, can be easily accommodated without creating a complete, costly metal mold for each core variant.Embodiments of the disclosure further utilize the separable mold parts to achieve precise temperature control over the mold in order to address any problems, such as certain core areas being prone to cracking or breakage.

[0033] Referring to the Fig. 1 and Fig. Figure 2 illustrates a perspective front view and a perspective rear view of a mold system 100 according to embodiments of the disclosure. Furthermore, it shows Fig. 3 a transparent perspective front view, and Fig. Figure 4 shows a transparent perspective side view of the form system 100 from the Fig. 1-2. It is recognized that, according to embodiments of the disclosure, the molding system 100 is used to produce a casting 102 ( Fig. 3-4) for investment casting. For the purposes of description, as in the Fig. As illustrated in Figures 3-4, the disclosure shows the component to be constructed as a turbomachine blade 104. It is readily understood that the teachings of the disclosure are applicable to any component suitable for investment casting and which is to contain an internal structure formed by a core.

[0034] The form system 100 contains a form 110 for receiving a selected core, which is chosen from several different cores. The core variants can assume any of a large number of shapes. In the Fig. 3 and Fig. The illustrated example 4 shows two different cores 112A and 112B (collectively “cores 112”) that together form an internal structure in the turbomachine blade, e.g., cooling channels, a supporting structure, etc. In the turbomachine blade example, a core 112A can form a section, including a leading edge, of the blade, while the core 112B forms a section, including a trailing edge, of the blade. In a non-restrictive example, any different turbomachine blades can be formed using a single leading-edge core 112A and a variety of different trailing-edge cores 112B. Fig. Figures 5-7 show schematic side views of several examples in which a single leading-edge core 112A is used and various differently shaped cores 112B are employed. It is recognized that the section of the component that changes can also differ from component to component, whereby, for example, the leading edge or a root section 118 can also vary for a blade.

[0035] Fig. 8 shows, in contrast to the Fig. 5-7 A top-down view of different cores 112A, 112B, wherein the difference is simply a dimensional or shape variant created by a deviation during core production, e.g., by additive manufacturing. In this setup, core-to-core variants can be identified by any method known today or developed in the future, such as, but not limited to, blue light scans or point cloud scans. The identified differences can be used to generate a model of the actual cores 112A, 112B, which can then be used to adjust the mold 110 accordingly, e.g., to obtain a desired distance between an inner surface 132 of the mold 110 and the core 112, to ensure proper positioning and thickness of a sacrificial material 130. Modifications to the mold 110 can be made during the mold's production (e.g.,(using additive manufacturing and / or computer-aided design software systems) and, in particular, separable mold parts 120 that form the mold. The core 112 can be formed in any manner known today or developed in the future. In one embodiment, the core 112 is formed by additive manufacturing, e.g., 3D printing.

[0036] The mold 110 contains several separable mold parts 120A-D (collectively “separable mold parts 120”) that can be joined together to create the mold. As shown in the Fig. As illustrated in Figures 1-4, the illustrated example provides for four mold parts 120A-D. However, it is understood that any number of separable mold parts 120, e.g., two or more, can be used. As is understood, the mold 110 is configured to form sacrificial material 130 from a sacrificial fluid (e.g., a sacrificial material in a flowable mold) around a selected core 112. The core 112 is positioned inside the mold 110 and is spaced from the inner surface 132 of the mold 110 such that the sacrificial fluid can easily flow between the core 112 and the inner surface of the mold to produce the casting 102. The sacrificial material can be any material known today or developed in the future that is suitable for injection into a fluid mold and that, in a solid state, is sufficiently rigid to retain its shape during the formation of a ceramic mold by investment casting.The sacrificial material may contain, but is not limited to, wax or polymer.

[0037] As in the Fig. 9 and Fig. As illustrated in Figure 10, any selected separable mold part 120 from several separable mold parts 120A-D in a given mold can contain a set of different interchangeable variants of these. In the illustrated example, a set of separable mold parts 120E ( Fig. 9) and 120F ( Fig. 10) for a section containing a trailing edge of a turbomachine blade 104. While two different interchangeable variants are illustrated, any number can be used to accommodate any number of different cores 112, for example creating sets with many similar molded parts. Each different interchangeable variant 120E, 120F of the selected separable molded part 120 can be configured to accommodate a different core 112 from among the several different cores 112. In the Fig. In the illustrated example 9, a separable molded part 120E is designed to accommodate the core 112B, while, as shown in Fig. Figure 10 illustrates that the separable mold part 120F is designed to accommodate a different core 112A in the same position within the mold 110. Each different interchangeable variant of a selected separable mold part 120 may differ in various ways, such as, but not limited to: the mold opening shape, size: length, width, height; the thermal cooling circuit (presence or path, as described elsewhere herein); the coefficient of thermal expansion; the heat transfer coefficient; the material and / or material properties, such as yield strength, grain boundary structure, surface finish, etc. In each case, the selected separable mold parts 120E, 120F are designed to be positioned in the same location inside the mold 110 to complete the mold, but they have different internal surfaces 132 to accommodate different cores 112A, 112B.As described below, separable molded parts 120E, 120F may include a number of additional features that enable, among other things, a suitable connection and thermal control.

[0038] Each separable molded part 120 can contain a metal alloy, an acrylic-based material such as, but not limited to, polymethyl methyl acrylate (PMMA), or a material with a glass transition temperature above 70°C (approximately 160°CF). When a metal alloy is used, the separable molded parts 120 can be easily manufactured with the aforementioned customer-specific structure, for example, using additive manufacturing. In particular, a metal powder-based additive manufacturing process can be used to form separable molded parts 120 from metal. Metal powder-based additive manufacturing can include, for example, direct metal laser melting (DMLM).It is understood that the general teachings of the revelation are equally applicable to other forms of metal powder-based additive manufacturing, such as, but not limited to, direct metal laser sintering (DMLS), selective laser sintering (SLS), electron beam melting (EBM), and possibly other forms of additive manufacturing. If the separable molded parts 120 contain an acrylic-based material or a material with a glass transition temperature above 70°C, the molded parts 120 can be produced, for example, by stereolithography or 3D printing (e.g., using stereolithography resins). Other processes can also be used to produce the separable molded parts 120, such as casting and machining.

[0039] Fig. Figures 11-14 show different views of selected separable mold parts 120C, 120D from an upper section of mold 110 in the Fig. 1-4, and Fig. Figures 15-18 show different views of selected separable mold parts 120A, 120B from a lower section of mold 110 in the Fig. 1-4. In particular, the Fig. 11 and Fig. 12 perspective views of matching separable molded parts 120C-120D; Fig. Figure 13 shows a lower view of both molded parts 120C, 120D; Fig. Figure 14 shows a perspective view of both mold parts 120C, 120D; Fig. 15 and Fig. Figures 16 show perspective views of matching separable molded parts 120A, 120B; Fig. Figure 17 shows a side view of both molded parts 120A, 120B; and Fig. Figure 18 shows a perspective view of both molded parts 120A and 120B. As illustrated, each separable molded part 120 can contain any structure required for a sealing connection with other molded parts. For example, the molded parts 120A-D can contain mating surfaces 136 configured to abut and mate with an adjacent molded part. The surfaces 136 can have any shape required to enable a mating pair, such as a flat and / or curved surface. The surfaces 136 are dimensioned to prevent a fluid of the sacrificial material 130 from passing through them when joined. Furthermore, a specific molded part(s) 120A-D can have sealing grooves 138 ( Fig. 13, 15-18) which are configured to accommodate a (not illustrated) gasket for sealing with an adjacent molded part. Furthermore, a certain molded part(s) 120C-D may contain upper-lower clamping ends 140 for a ceramic core. The separable molded parts 120A, 120B, 120C, 120D are further designed to be combined and joined together, wherein, for example, the separable molded parts 120A and 120B, which form a lower section of the mold 110, may be identical across several blade assemblies that have different separable molded parts 120C, 120D, which form the upper section of the mold 110.

[0040] Certain molded part(s) 120A-D may also contain a receiving device 144 for a core positioning device. Each receiving device 144 for a core positioning device is configured to accommodate a core positioning device 146 ( Fig. 2 and Fig. 19) to accommodate a core 112 extending through a respective mold part 120 to make contact with the core 112 and to position it appropriately with respect to the inner surface 132 of the mold 110. That is, to position the core 112 at a distance from an inner surface 132 of the mold 110 to define the position and thickness of the sacrificial material 130 around the core. The receiving devices 144 for the core positioning device are thus another feature of each separable mold part 120, which can be varied to accommodate different cores 112. Each receiving device 144 for a core positioning device can include a hole extending from the inner surface 132 of the mold 110 to an outer surface 145 of the mold 110 and can include a countersink on the outer surface of the mold 110. The mold system 100 can incorporate several core positioning devices 146 ( Fig. 2) which are configured to position the selected core 112 via the receiving devices 144 for the core positioning device in at least one of the several separable molded parts 120. In one embodiment, each core positioning device 146 ( Fig. 2) have a selected length to position a respective part of a selected core 112 with respect to the inner surface 132 of the shape 110. In this case, a set of core positioning devices 146 ( Fig. 2) provided for each molded part 120 and / or for each different core 112. In a further embodiment, the core positioning device 146 ( Fig. 19) in each receiving device 144 for the core positioning device, be adjustable to accommodate a variety of molded parts 120 and / or a number of different cores 112. For example, a core positioning device 146, as in Fig. Figure 19 illustrates a head 148 coupled to a rod 150. The head 148 can be threaded to engage with a mating threaded receiving device 144 for the core positioning device in a separable molded part 120 and to be adjustable within it. When the head 148 is screwed in, the position of the rod 150 changes with respect to the inner surface 132 to make contact with an outer surface of different cores 112. The head 148 can include any structure required to enable the adjustment, such as a screwdriver head. In this way, any adjustable core positioning device 146 ( Fig. 19) be set up to position a number of the several different cores 112 in the form 110.

[0041] Returning to the Fig. 11-18 can contain certain separable molded parts (e.g. 120A) in Fig. 15, (an) airflow path(s) 152 containing to allow air to exit the mold 110. The airflow path(s) 152 may be provided where necessary to ensure the removal of air during operation.

[0042] Referring to the Fig. 1, 2 and 14-18, several separable molded parts 120A-D can be attached to each other in different ways. As shown in the Fig. 1 and Fig. As illustrated in Figure 2, fasteners 160 can be used to selectively couple several separable molded parts, e.g., 120B with 120D and 120A with 120C. The fasteners 150 can take any form to hold the molded parts 120A-D together during operation, such as external clamps held in position by bolts, seats in molded parts (as illustrated), screws, etc. Certain separable molded parts 120A-D can also include matching fastener holes 162 to receive a fastener (not illustrated), e.g., a threaded bolt, a screw, etc., to selectively fasten molded parts together. For example, the separable molded parts 120C and 120D, as shown in the Fig. 11 and Fig. Figure 12 illustrates, including matching mounting holes 162, and as shown in the Fig. 15 and Fig. As illustrated in Figure 16, the separable mold parts 120A, 120B can contain matching fastener holes 162. The matching fastener holes 162 (in one or both separable mold parts that are fastened) can include a mechanism to secure the fastener, such as mating threads, a snap-fit, etc. In addition to the individual fastening of the separable mold parts 120A-D, any mold locking process known today or developed in the future can be used to further hold the mold 110 together during use.

[0043] The molding system 100 further provides mechanisms for controlling the temperature of the mold 110. In particular, the separable mold parts 120 ensure more precise thermal control than conventional systems. Temperature control of the mold 110, and especially of each separable mold part 120 or of an area containing a specific separable mold part 120, may be desirable for several reasons. For example, temperature control enables: to maintain a desired viscosity and / or temperature of a sacrificial fluid, to maintain a desired temperature of a core 112, to protect the mold 110 from damage due to overheating, and to preheat the mold 110 to ensure a proper casting process. Furthermore, certain sacrificial fluids, e.g., wax or certain polymers, may require a specific temperature to create a fluid mold and / or to maintain a suitable temperature for producing a casting 102. As described below, the temperature control according to embodiments of the disclosure can be customized and controlled in various ways.

[0044] In one embodiment, such as in the Fig. 11, Fig. 12, Fig. 15 and Fig. As illustrated in Figure 16, each separable mold part 120A-D can further include a thermally conductive mold channel 164 configured to guide a temperature-controlled thermal fluid through it in order to control the temperature of at least the respective separable mold part 120. The thermally conductive mold channels 164 can be considered a "closed circuit" because they are configured to provide a complete path for the temperature-controlled thermal fluid 176 to follow when supplied by the thermal fluid controller 180 of the mold to one or more inlet ports, through the respective part of one or more mold parts 120A-D, and subsequently to one or more outlet ports. The temperature-controlled thermal fluid 176 used can be any thermally conductive fluid known today or developed in the future, e.g., air, water, antifreeze, etc., suitable for the mold material.The temperature-controlled thermal fluid 176 can supply heat and / or cool a respective separable mold part 120A-D. The temperature-controlled thermal fluid 176 can be used to preheat the mold 110 and / or to maintain a temperature during the formation of the casting 102. It is recognized that, although the temperature-controlled thermal fluid 176 passes through a respective separable mold part 120A-D, it can transfer thermal energy not only to / from the specific mold part through which it passes, but also to an adjacent structure, the sacrificial fluid, and / or the core 112.

[0045] Each different interchangeable variant of the at least one selected separable mold part 120A-D can contain a thermally conductive mold channel 164 that differs from the thermally conductive mold channel in the other separable mold parts of the set. In this way, each variant of a selected separable mold part 120A-D can have its respective thermally conductive path, which is adapted to the situation for which the mold part is designed. For example, as in Fig. Figure 9 illustrates that a particular core 112B requires thermally conductive channels 164 running in close proximity to the inner surface 132 to maintain the core and / or the sacrificial material 130 fluid at a specific desired temperature, e.g., at a distance of less than 0.5 cm. In contrast, another core 112B, as shown in Fig. Figure 10 illustrates thermally conductive molded channels 164 that are not located so close to the inner surface 132, e.g., more than 0.5 cm away. Again, each separable molded part 120A-D and any thermally conductive molded channels 164 therein can be adapted to the expected situation for which it was designed. The adaptation of the thermally conductive molded channels 164 can take any form, including, but not limited to: number of channels, cross-sectional shape, length, shape, position / path, etc., and temperature, type, flow rate, etc., of the temperature-controlled thermal fluid.

[0046] Fig. Figure 20 shows a schematic cross-sectional view of a mold 110 containing various heat-conducting mold channels 164A-E, illustrating exemplary paths and / or positions where they can be used. As in Fig. As illustrated in Figure 20, one or more thermally conductive mold channels 164A-E (collectively “thermally conductive mold channels 164”) can take any path through a given molded part, including, but not limited to: straight line 164A, curved line 164B, loop(s) 164C, screw or spiral 164D, sinusoidal shape 164E, etc. As further illustrated in Fig. As illustrated in Figure 20, not all separable molded parts 120 need to contain a heat-conducting mold channel, where, for example, part 120K is free of channels. As further shown in Fig. Figure 20 illustrates that one or more external heat-conducting mold channels 168 can also be provided to guide channel paths on the outer surface 145 of, for example, the molded part(s) 120M. Any currently known or future developed connections 170 on the outer surface 145 of the molded part(s) 120 can be provided for flow-related connection with external channels 174 (an example is shown in Figure 20). Fig. 20 illustrated) shall be provided which communicate fluidly with a thermal fluid control 180 of the mold which is set up to control a temperature of each of the several separable mold parts 120K-N or of an area which contains a part of the selected separable mold parts.

[0047] The thermal fluid control unit 180 of the mold can include any currently known or future developed temperature control system for a temperature-controlled thermal fluid to generate any number of flows of a temperature-controlled thermal fluid 176, each at a specific temperature, e.g., a multi-stage heat exchanger such as the water temperature control unit of the Thermolater TW series. Any pumps required for moving the temperature-controlled thermal fluid 176 can also be provided. The thermally conductive mold channels 164 can be configured to control the temperature of a specific separable mold part 120 and / or a sacrificial fluid supply area 190. With respect to these areas, one or more thermally conductive mold channels 164 can act to control the temperature of a defined sacrificial fluid supply area 190A-C (3 illustrated).Each region 190A-C is configured to receive a sacrificial fluid to form a sacrificial material around the core at a specific temperature. Each region 190A-C can be defined, for example, by any desired area and / or volume of the mold 110, any area and / or volume of the void to be filled by the sacrificial fluid 130, and / or any area and / or volume of the core 112. Each separable mold part 120A-C can contain at least one sacrificial fluid supply region 190A-C, meaning that the regions do not necessarily correspond to mold parts.

[0048] At least one separable mold part 120 can have a temperature-controlled thermal fluid 176 flowing through it, which has a temperature different from that of another separable mold part. Likewise, each region 190A-C can have a temperature-controlled thermal fluid 176 flowing through it or near it in such a way that it has a different temperature than another region. In each case, a thermally conductive mold channel 164 can control the temperature of at least the sacrificial material fluid 130 within at least one respective separable mold part 120 and possibly in other regions, such as those downstream of the mold part in which the channel is located. Each region 190A-C can, for example, have a temperature-controlled fluid therein to, for example,The viscosity and other flow properties of the sacrificial fluid 130 in the respective area can be controlled to accommodate any casting / injection aspects specific to that area, including, but not limited to, difficult wetting / flow conditions and / or aspects of the core 112. For example, the temperature of an area 190A-C can be controlled based on a property of the core 112, such as fragility, difficult wetting, etc., within that area. In this way, damage to the core 112 and / or the flow of the sacrificial fluid can be easily controlled, and a high-quality formation of the casting 102 can be achieved. Furthermore, certain mold materials 110 may require the use of a sacrificial fluid with a specific maximum temperature that will not damage the mold, e.g., a PMMA mold.The temperature of each 190A-C zone can also be controlled to prevent mold damage caused by overheating of the sacrificial fluid. The temperature of each 120 molded part can be controlled similarly.

[0049] Referring to Fig. Figure 21 illustrates a schematic cross-sectional view of a mold system 200 according to a further embodiment of the disclosure. The mold system 200 can be substantially similar to the mold system 100 as described herein. For example, the mold system 200 includes a mold 210 to receive the core 112, and the mold 210 includes several separable mold parts 120A-D that can be joined together to form the mold and are configured to form the sacrificial material around the core from the sacrificial fluid. Furthermore, a selected separable mold part, e.g., 120E, F ( Fig. 9-10), of the several separable molded parts 120 a set of different interchangeable variants of the at least one selected separable molded part. Each different interchangeable variant of the selected separable molded part 120 can be configured to accommodate a different core 112 from several different cores. In the embodiment according to Fig. However, the mold system 200 can have more than one sacrificial fluid inlet 284 to accommodate more than one sacrificial fluid flow 286A-C. For example, each separable mold part 120 can have one or more sacrificial fluid inlets 284. Furthermore, some separable mold parts 120 can be free of sacrificial fluid inlets, such as part 120A in the example shown. Fig. 21.

[0050] Additionally, the mold system 200 can further include a sacrificial fluid heating system 202 to control the temperature and viscosity of the sacrificial fluid 130 and indirectly control the temperature of the molded parts 120. The sacrificial fluid heating system 20 can operate alone or in addition to the thermal fluid control 180 of the mold (where the latter is in Fig. 21 for the sake of clarity compared to Fig. 20 is illustrated in a simplified manner). The temperature control for the sacrificial fluid can be based on the separable mold parts 120 and / or areas. With regard to the areas, the mold system 200 can include several sacrificial fluid supply areas 290A-C configured to receive flows of a sacrificial fluid 286A-C to form a sacrificial material 130 around the core. One or more sacrificial inlets 284A-C, alone or in conjunction with the heat-conducting mold channels 164A-E ( Fig. 20) can act to control the temperature of a sacrificial fluid supply area 290A-C (3 illustrated) configured to receive sacrificial fluid to form a sacrificial material around the core. As mentioned, each area 290A-C can be defined, for example, by any desired area and / or volume of the mold 210, any area and / or volume of the void to be filled with the sacrificial fluid, and / or any area and / or volume of the core 112. Each separable mold part 120A-D can contain at least one sacrificial fluid supply area 290A-C. Each area 290A-C can have a temperature of the sacrificial fluid injected therein (and / or a temperature of the temperature-controlled thermal fluid sent through it) that is controlled, for example, toThe viscosity and other flow properties of the sacrificial fluid 130 in the respective area are controlled to accommodate any injection aspects therein, including, but not limited to, difficult wetting / flow conditions and / or aspects of the core 112. The temperature of the sacrificial fluid received in each sacrificial fluid supply area 290A-C can, for example, be based on a property of the core 112, such as fragility, difficult wetting, etc., in the respective sacrificial fluid supply area. The fluid flows 286A-C of the sacrificial material 130 can also be controlled based on the separable molded parts 120A-D into which they are injected.

[0051] The sacrificial fluid heating system 202 can include any sacrificial heating unit(s) known today or developed in the future for generating one or more sacrificial fluid flows 286A-C at a specific temperature, e.g., a multi-stage heat exchanger, or a series of heating units. In the latter example, the heating system 202 for use with wax can include a series of Dura-Bull pressurized wax injectors, each generating liquid wax at a different temperature. In any case, the sacrificial fluid heating system 202 can be configured to heat multiple flows 286A-C of the sacrificial fluid to different temperatures. That is, each sacrificial fluid flow 286A-C can have a different temperature, as controlled by the sacrificial fluid heating system 202.In this way, one sacrificial fluid supply area 290A can receive one of the several sacrificial fluid flows 286A at a first temperature, and another sacrificial fluid supply area 290B can receive a different sacrificial fluid flow 286B at a second, different temperature. Alternatively, one separable molded part 120C can receive one sacrificial fluid flow 286A at a first temperature, and another separable molded part 120B can receive a different sacrificial fluid flow 286Cf at a second, different temperature. The temperatures can be selected to address any of the aforementioned reasons for providing temperature control.

[0052] In operation, as shown in the flowchart according Fig. Figure 22 illustrates a method for forming a casting 102 for investment casting according to embodiments of the disclosure in a process P1 that includes providing several separable mold parts 120 for the mold 110 for forming the casting 102, which is additively manufactured, e.g., by DMLM, stereolithography, etc. As mentioned, several mold parts 120A-D can be a set of different interchangeable variants of a selected separable mold part, e.g., 120A, 120B, 120C, or 120D ( Fig. 1-2), or 120K, 120L, 120M or 120N ( Fig. 20), included. Each different interchangeable variant of the selected separable molded part 120 can be configured to accommodate a different core 112 from several different cores ( Fig. 9, Fig. 10) to be included.

[0053] As described, the mold 110, as illustrated in process P2, can be formed around a selected core 112 from among several different cores 112 by coupling two or more separable mold parts 120 selected according to the mold. The separable mold parts selected according to the mold, that is, those from the set (or sets) chosen to be used in the mold 110, are selected to accommodate the selected core from among the several different cores. Each separable mold part 120 can contain a thermally conductive mold channel 164 configured to deliver a temperature-controlled thermal fluid 176 ( Fig. 20) to pass through it in order to control the temperature of at least the respective separable mold part or of a region 190 in the mold. The formation of the mold 110 may include fastening the two or more separable mold parts selected according to the mold to one another with fastening means 160. The formation of the mold 110 may further include positioning the selected core 112 in the mold 110 using a receiving device 144 for a core positioning device in at least one of the several separable mold parts. The positioning may involve the use of several core positioning devices 146 ( Fig. 2) comprise, which are configured to position the selected core 112 in at least one of the several separable molded parts 120 by means of the receiving device 144 for the core positioning device. That is, select which of several positioning devices 146 ( Fig. 2) for a specific core 112. Alternatively, positioning can be achieved using an adjustable core positioning device 146 ( Fig. 19) included in each receiving device 144 for a core positioning device. Each adjustable core positioning device 146 is configured to position a number of the multiple different cores 112 in the mold.

[0054] Once the mold 110 is formed, the casting 102 can be cast in a process P3 by introducing a sacrificial fluid 130 into the mold and around the selected core. Process P3 can further control the temperature of several sacrificial fluid supply areas 190A-C ( Fig. 20), 290A-C ( Fig. 21) contained in the mold 110 or 210. Each area is defined such that it receives the sacrificial material fluid 130 to form a sacrificial material around the core, which is positioned inside the mold, at a specific temperature. The temperature of each separable mold part 120A-D ( Fig. 1-2) can also be controlled. As in Fig. As illustrated in Figure 22, process P3 can include temperature control for each of the multiple separable mold parts and / or areas, e.g., using control 180 for the thermal fluid of the mold alone. Alternatively, process P3 can be performed as shown in Figure 22. Fig. Figure 22 illustrates the heating of multiple flows 286A-C ( Fig. 21) of the sacrificial fluid to different temperatures, e.g., using the sacrificial fluid heating system 202, and directing one of the several flows of the sacrificial fluid, e.g., 286C, at a first temperature to a first sacrificial fluid feed area 290C of the mold, and directing another of the several flows of the sacrificial fluid, e.g., 286B, at a second, different temperature to a second, different sacrificial fluid feed area 290B. Alternatively, process P3 can include directing one of the several flows of the sacrificial fluid, e.g., 286B, at a first temperature to a first separable mold part 120D of the mold and directing another of the several flows of the sacrificial fluid, e.g., 286C, at a second, different temperature to a second, different separable mold part 120B.Process P3 may further include the use of the mold thermal fluid controller 180 to control the temperature of one or more areas 190A-C and the sacrificial fluid heating system 202 to control the temperature of the sacrificial fluid in one or more areas 290A-C. The areas 190A-C, as defined for the controller 180, and the areas 290A-C, as defined for the system 202, may, but need not, be identical.

[0055] Once the casting 102 has been formed, the mold 110 can be removed in any manner known today or developed in the future, e.g., by loosening the mold parts 120. As described, the casting 120 can be used in any investment casting process known today or developed in the future.

[0056] The mold systems 100 and 200, as described herein, offer several advantages compared to conventional systems. Mold systems 100 and 200 allow the injection of a sacrificial fluid at lower pressures, for example, from 34.5 kilopascals (kPa) to 344.5 kPa (5–50 psi), compared to conventional systems, for example, at or above 13.8 megapascals (MPa). Furthermore, mold systems 100 and 200 allow injection at optimized sacrificial fluid temperatures and viscosities, as the molds have their own individual temperature control. These optimized sacrificial fluid temperatures, viscosities, and injection pressures prevent damage to molds 110 and 210 and core 112 due to thermal and pressure stresses. Mold systems 100 and 200 also provide modular and adaptable molds for handling a variety of cores. The separable molded parts 120 can be reused as needed.The mold thermal fluid control 180 can be used to directly preheat the molds 110 and 210, and indirectly preheat the cores 112, which helps to improve the quality of the casting 102. The mold thermal fluid control 180 also enables precise temperature control of defined areas and / or separable mold parts to address injection problems specific to that area, mold part, and / or the core part located therein. Similarly, the sacrificial fluid heating system 202 enables precise temperature control of the sacrificial fluid used in defined areas and / or separable mold parts to address injection problems specific to that area, mold part, and / or the core part located therein. The teachings of this disclosure can be applied to a wide variety of mold materials and mold-making processes.Mold inventories can be created to accommodate significant variations in cores and / or different components to be produced. The ability to use additive manufacturing for both molds 110 and 210, as well as cores 112, offers considerable time and cost savings compared to conventional casting processes. Furthermore, additive manufacturing allows for faster correction of problems discovered during the formation of the casting, such as core cracking, and enables earlier resolution of issues throughout the entire process—that is, during the casting process itself, rather than during the investment casting stage.

[0057] Embodiments of the disclosure further include an early assessment of the mechanical integrity of a ceramic core for ceramic cores used during injection molding and casting applications. Potential mechanical damage (e.g., cracking, breakage, or failure) of the ceramic cores during the casting of a metal melt and a monocrystalline furnace solidification process can be predicted. This allows, for example, the configuration (e.g., shape, size, etc.) of ceramic cores to be adjusted very early in the investment casting process in order to reduce defects of ceramic cores during the subsequent casting of a metal melt.

[0058] A process is disclosed in which ceramic cores are tested at a very early stage of an investment casting process. Instead of performing all the design steps up to the casting of a metal melt before determining the stability of ceramic cores, the testing method disclosed herein uses a sacrificial fluid to simulate stresses on ceramic cores caused by the metal melt. The viscosity of the sacrificial fluid is controlled by adjusting the temperature and / or pressure to match the viscosity of the metal melt. This saves a significant amount of time and money because defective ceramic cores are detected early in the casting process rather than after the metal melt has been poured.

[0059] As in Fig. As shown in Figure 23, an investment casting process may comprise the following: A1) designing and producing a ceramic core; A2) producing a wax pattern using the ceramic core; A3) forming a wax pattern cluster; A4) coating the wax cluster with a ceramic material (e.g., slurry, plaster) to form a mold; A5) dewaxing and firing the mold (e.g., for strength); A6) melting an alloy in a vacuum (or in air); A7) pouring the molten metal alloy into the mold; A8) chipping off the ceramic shell to expose the casting; and A9) performing inspection and finishing operations on the casting. Such an investment casting process (e.g., A1-A9) is well within the scope of a person skilled in the art and may, of course, include fewer or additional processes.

[0060] In some cases, the ceramic core may break, crack, or be damaged in some other way during the casting of the molten alloy into a ceramic mold (e.g., process A7). This damage (JA, A10) may be detected, for example, during the inspection of the casting in process A9. If a problem with the ceramic core is identified, modifications (process A11) to the ceramic core may be required, which is time-consuming and costly. The process then returns to A2, where another wax pattern is produced using the reshaped ceramic core, and the investment casting process is repeated with the reshaped ceramic core. Further reshaping by trial and error may be required if the new ceramic core is found to be defective (JA, A10). Damage to the ceramic core may necessitate a reshaping of mold 110.

[0061] According to embodiments of the disclosure, as in Fig. As shown in Figure 23, a ceramic core can be inspected very early in the investment casting process. For example, the ceramic core can be inspected (process B1) before a corresponding wax model is created in A2. If the inspected ceramic core is found to be defective (YES, B2), it can be reworked at B3 and then inspected again at B1. If the ceramic core is found to be free of defects (NO, B2), the process continues to A2, and a wax model is created. The inspection / rework processes (B1, B2, B3) can be repeated as needed until a defect-free ceramic core has been produced.

[0062] According to embodiments, the ability to modify the viscosity and flow properties of the sacrificial material 130 fluid in one or more separable molded parts 120 of the mold 110 can be used to simulate stresses on one or more parts of the ceramic core 112 caused by a molten metal. This allows the ceramic core 112 to be inspected very early in the investment casting process without actually having to cast a molten metal.

[0063] As described above, the mold 110 contains several separable mold parts 120 (e.g., mold parts 120A-D, Fig. 1-4), which can be connected to each other to create the mold 110. The mold 110 is designed to form a sacrificial material 130 from a sacrificial fluid 130 around a selected ceramic core 112. The ceramic core 112 is positioned inside the mold 110 and is arranged at a distance from the inner surface 132 of the mold 110, so that the sacrificial fluid 130 can easily flow between the ceramic core 112 and the inner surface of the mold 110 to produce a casting 102.

[0064] The viscosity of the sacrificial material 130 fluid can be controlled to mimic the expected viscosity of the molten metal used in the investment casting process. For example, the sacrificial material heating system 202 ( Fig. 21) include one or more heating devices to heat the sacrificial fluid 130 such that its viscosity matches the expected viscosity of the molten metal. The sacrificial heating system 202 may further include one or more pumps for injecting the sacrificial fluid 130 at the desired viscosity into one or more openings or areas of the mold 110. If one or more sacrificial inlets 284 are located in one or more of the separable parts 120 of the mold 110, the sacrificial heating system 202 may supply the sacrificial fluid 130 at the same viscosity or at different viscosities to one or more of the separable parts 120 of the mold 110 via one or more of the sacrificial inlets 284.Furthermore, the temperature of each separable molded part 120 can also be controlled by the control 180 for thermal fluid of the mold (. Fig. 20-22) can be specifically regulated by passing a temperature-controlled thermal fluid 176 through it. In this respect, as detailed above, for example, with regard to process P3 and the Fig. As described in sections 20-22, the viscosity of the sacrificial fluid 130 can be controlled throughout the entire mold 110, for example by adjusting the temperature of the sacrificial fluid 130 (e.g., using the sacrificial heating system 202) and / or by adjusting the temperature of one or more of the separable mold parts 120 (e.g., using the mold thermal fluid control 180). A viscosity control system 300 ( Fig. 23, Fig. 24) shall be provided for the control of the sacrificial material heating system 202 and the thermal fluid control 180 of the mold in order to regulate the viscosity(s) of the sacrificial material fluid 130 used during the testing process (process B1) for the ceramic core 112.

[0065] The process B1 for testing the ceramic core 112 according to embodiments is described in greater detail in Fig. Figure 24 illustrates this. B1-1 provides viscosity data for one or more metal alloy melts at several different temperatures. This viscosity data is readily available and can be obtained, for example, from datasheets, a foundry, a source of the metal alloy, or any other suitable source.

[0066] In step B1-2, the sacrificial fluid 130 (e.g., by the sacrificial heating system 202) is heated to a predetermined temperature (T) at which the sacrificial fluid 130 has a viscosity (VISC) corresponding to that of a given metal alloy melt. In step B1-3, the core 110 is filled with the sacrificial fluid 130 at this viscosity (VISC) to create a wax mold around the ceramic core 112. In step B1-4, the wax mold is removed to expose the underlying ceramic core 112. In step B1-5, the ceramic core 112 is examined to determine whether the flow of the sacrificial fluid 130 at this viscosity (VISC) into the mold 110 caused any mechanical damage to the ceramic core 112. If there is damage to the ceramic core (YES, B2), the ceramic core can be reshaped at B3 and then retested at B1.Feedback regarding any damage to the ceramic core discovered during the investigation process (B1-5) can be provided to the ceramic core design team, who can use the feedback to redesign the ceramic core to prevent such damage.

[0067] If the ceramic core is found to be non-defective (NO, B2), the process proceeds to A2, and a wax model is produced. The testing process (B1) for the ceramic core can be repeated using a sacrificial fluid of material 130 with one or more additional viscosities to determine the effect that such viscosities may have on a ceramic core 112. The same ceramic core 112, if found to be non-defective (NO, B2), can be retested using a sacrificial fluid of material 130 with one or more additional viscosities to determine the effect that such viscosities may have on this ceramic core 112.

[0068] In the preceding description of process B1 for checking the ceramic core 112, the sacrificial fluid 130 can have the same viscosity throughout the entire mold 110. However, according to embodiments, the viscosity of the sacrificial fluid 130 in one or more of the separable mold parts 120 can be controlled by the mold thermal fluid controller 180 ( Fig. 20, Fig. 21) and / or by the sacrificial material heating system 202 ( Fig. 21) be adapted.

[0069] Referring again to the Fig. 24. Process B1-3 can be extended to include the use of a sacrificial fluid 130 with two or more different viscosities. This can be done, for example, as described in greater detail in relation to the Fig. 20 and Fig. As described in Figure 21, this can be achieved by adjusting the temperature of one or more separable mold parts 120 (Process B1-3A). According to embodiments, a temperature-controlled thermal fluid 176, controlled by the thermal fluid controller 180 of the mold, can be passed through one or more separable mold parts 120 to selectively adjust their temperature. The mold 110 is then filled with the sacrificial material fluid 130 of a given viscosity (or one or more different viscosities). Depending on the temperature of each of the separable mold parts 120, the resulting viscosity of the sacrificial material fluid 130 in each of the separable mold parts 120 of the mold 110 can increase, decrease, or remain constant.Advantageously, this allows the inspection of different sections of the ceramic core 112, which are arranged in one or more different separable molded parts 120 of the mold 110, using a sacrificial material fluid 130 which has one or more different viscosities.

[0070] Different viscosities of the sacrificial material 130 fluid can also occur at one or more of the separable molded parts 120 of the mold 110, as described in greater detail with regard to the Fig. 21, provided using the sacrificial material heating system 202 (process B1-3B). Process B1-3B can be used alone or in combination with process B1-3A to vary the viscosity of the sacrificial material fluid 130 in one or more of the separable molded parts 120 of the mold 110.

[0071] The foregoing drawings show part of the associated processing according to various embodiments of this disclosure. In this respect, each block within a flowchart of the drawings represents a process associated with embodiments of the described method. It should further be noted that in some alternative implementations, the actions mentioned in the drawings or blocks may occur in a different order than shown in the figure, or, for example, may in fact be carried out substantially in parallel or in reverse order, depending on the action involved. Furthermore, a person skilled in the art will recognize that additional blocks may be added to describe the processing.

[0072] The terminology used herein serves solely to describe certain embodiments and is not intended to be limiting to the disclosure. In the sense used herein, the singular forms "a," "an," and "the" are to include the plural forms unless the context clearly indicates otherwise. Furthermore, it is understood that the expressions "has" and / or "show," when used in this description, indicate the presence of the specified features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more further features, integers, steps, operations, elements, components, and / or their groups.“Optional” or “choice” means that the event or circumstance described below may or may not occur, and that the description includes cases in which the event occurs as well as cases in which it does not.

[0073] An approximation language, such as that used herein in the entire description and the claims, may be applied to modify any quantitative representation that could permissibly vary without altering the basic function with which it relates. Accordingly, a value modified by an expression or expressions such as "about," "approximately," and "essentially" shall not be restricted to the exact stated value. In at least some cases, the approximation language may correspond to the accuracy of an instrument for measuring the value. Here, and throughout the entire description and the claims, range boundaries may be combined and / or interchanged, such ranges being identified and encompassing all the subranges contained therein, unless otherwise indicated by the context or the language. "Approximately" or "approximately""Approximately", as applied to a specific value of a range, applies to both values, and unless otherwise dependent on the accuracy of the instrument measuring the value, it may indicate + / - 10% of the stated value(s).

[0074] The corresponding structures, materials, actions, and equivalents of all means or step-plus functional elements in the following claims are intended to comprise any structure, material, or action for performing the function in combination with other claimed elements, as specifically claimed. The description of this disclosure has been presented for illustrative and descriptive purposes but is not intended to be exhaustive or limited to the disclosure as disclosed. Many modifications and alterations will be apparent to those skilled in the art without deviating from the scope and framework of the disclosure.The embodiment was chosen and described in order to best explain the principles of the disclosure and its practical application, and to enable other persons skilled in the art to understand the disclosure for various embodiments with different modifications suitable for the specific intended use.

[0075] Forming system 100 for the formation of a casting for investment casting, in which the mechanical integrity of a ceramic core 112 can be checked by changing the viscosity.A method for testing a ceramic core 112 used in an investment casting process comprises: positioning the ceramic core 112 inside a mold 110, 210 to receive a sacrificial fluid 284 in order to form a sacrificial material 130 on at least one section of the ceramic core 112, wherein the ceramic core 112 has a predefined layout; controlling the viscosity of the sacrificial fluid 284 during the casting around the ceramic core 112 using the mold 110, 210, in order to simulate an expected viscosity of a molten metal to be used during a subsequent investment casting process using the ceramic core 112; and evaluating any mechanical damage to at least one area of ​​the ceramic core 112 caused by the casting of the sacrificial fluid 284. PARTS LIST: 20 Sacrificial Material Heating System 100 Form system 102 Cast item 104 Turbomachinery blade 110 Form 112 core 118 Root section 120 separable molded part 120 Removing molded parts 130 pieces of victim material 132 inner surface 136 surfaces 138 sealing grooves 140 upper-lower clamping ends for ceramic core 144 Receiving device for a core positioning device 145 outer surface 146 core positioning devices 148 head 150 staff 152 airflow paths 160 fasteners 162 fastening holes 164 thermally conductive mold channel 168 external heat-conducting mold channels 170 connections 174 external channels 176 temperature-controlled thermal fluid 180 Control for thermal fluid of the mold 190 Sacrificial material fluid supply area 200 Form system 202 Sacrificial material fluid heating system 210 Form 284 Sacrificial material fluid inlet 112A core 112B core 120A separable molded parts 120B separable molded parts 120°C separable molded parts 120D separable molded parts 120E separable molded parts 120F separable molded parts 120K part 120M molded part 164A straight line 164B curved line 164C Loops 164D spiral 164E sine wave 286A Sacrificial material fluid flow 286B Sacrificial material fluid flow 286C sacrificial fluid flow 290A Sacrificial fluid supply area 290B Sacrificial fluid supply area 290C first sacrificial material feed area

Claims

[1] Method for testing a ceramic core (112) used for investment casting, the method comprising: Positioning the ceramic core (112) inside a mold (110, 210) to receive a sacrificial fluid (284) in order to form a sacrificial material (130) on at least one section of the ceramic core (112), wherein the ceramic core (112) has a predefined layout; during the casting of the sacrificial fluid (284) around the ceramic core (112, 112A, 112B) using the mold (110, 210), controlling the viscosity of the sacrificial fluid (284) to simulate an expected viscosity of a molten metal used during a subsequent investment casting process using the ceramic core (112); and Evaluating mechanical damage to at least one area of ​​the ceramic core (112) caused by the pouring of the sacrificial fluid (284). [2] Method according to claim 1, wherein the mechanical damage includes tearing or breaking of the ceramic core (112). [3] Method according to claim 1 or 2, further comprising, after evaluation, a modification of the predefined layout of the ceramic core (112). [4] The method of claim 3, further comprising repeating the positioning, controlling the viscosity, evaluating and modifying until the casting of the sacrificial fluid (284) does not damage the ceramic core (112). [5] Method according to any one of the preceding claims, further comprising forming the shape (110, 210) by attaching several separable mold parts (120) to one another. [6] Method according to claim 5, further comprising controlling a temperature of each of the several separable molded parts (120). [7] Method according to claim 6, wherein at least one of the several separable molded parts (120) includes a heat-conducting channel (164) therein, which is configured to guide a thermal fluid (176) through it in order to control the temperature of at least one of the several separable molded parts (120), wherein controlling the viscosity of the sacrificial material fluid (284) includes controlling the temperature of at least one of the several separable molded parts (120) by guiding the thermal fluid (176) through the heat-conducting channel (164). [8] A method according to any one of claims 5-7, further comprising: Heating several flows of the sacrificial material fluid (284) to different temperatures in order to control the viscosity of each of the several flows of the sacrificial material (130); and Each of the multiple flows of the sacrificial material fluid (284) is directed to a respective separable molded part (120) of the multiple separable molded parts (120). [9] A method according to any one of claims 5-7, further comprising: Heating several flows of the sacrificial material fluid (284) to different temperatures in order to control the viscosity of each of the several flows of the sacrificial material (130); and Each of the several flows of the sacrificial material fluid (284) is directed to a respective separable molded part (120) of the several separable molded parts (120); wherein at least one of the several separable molded parts (120) further includes a heat-conducting channel (164) which is arranged to guide a thermal fluid through it in order to control the temperature of at least one of the several separable molded parts (120), wherein the control of the viscosity of the sacrificial material fluid (284) further includes controlling the temperature of at least one of the several separable molded parts (120) by guiding the thermal fluid through the heat-conducting channel (164). [10] Testing system for testing a ceramic core used for investment casting, which has: a form (110, 210) containing the ceramic core (112) for receiving a sacrificial fluid (284) to form a sacrificial material (130) on at least one section of the ceramic core (112), wherein the ceramic core (112) has a predefined layout; a viscosity control system (300) for controlling the viscosity of the sacrificial fluid (284) during the casting of the sacrificial fluid (284) around the ceramic core (112) in order to simulate an expected viscosity of a metal melt used during a subsequent investment casting process using the ceramic core (112); and an evaluation system for assessing the ceramic core (112) in order to detect mechanical damage caused by the pouring of the sacrificial fluid (284) on at least one area of ​​the ceramic core (112).

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