Centrifugal apparatus for producing cast materials by centrifugal SHS casting

Abstract

The invention relates to the field of casting technologies, and more particularly to centrifugal apparatus for producing cast materials synthesized during the combustion of highly exothermic powder compositions using self-propagating high-temperature synthesis (SHS) methods. The present centrifugal apparatus comprises a rotatable arm of a rotary centrifuge, said rotatable arm being mounted on a supporting base and having two pivotable baskets arranged symmetrically on the beam thereof, the baskets having reaction units for receiving a refractory mould containing an exothermic SHS composition. The apparatus is provided with a remotely disposed computer console for controlling each of the following: a system for actuating an electric motor of the rotor, a system for cooling a water-cooled segmented shell, a system for the laser ignition of SHS compositions, and a backup system for igniting compositions by means of an electrical tungsten coil. In the laser ignition system, an optical device is used to deliver laser radiation, said device being mounted proximate the axis of rotation, wherein a beam is refracted by a prismatic mirror onto the surface of an exothermic SHS composition. In the cooling system, pipes for the supply and removal of water via shutoff valves, a heat exchanger and centrifugal circulating pumps are connected to a tank of the cooling system. The technical result is an increase in the efficiency of the process of producing cast materials and an increase in the quality of the materials produced.

Description

[0001] CENTRIFUGAL UNIT FOR PRODUCING CAST MATERIALS BY CENTRIFUGAL SHS CASTING METHODS

[0002] DESCRIPTION

[0003] The invention relates to the field of foundry technologies, namely to centrifugal units with a vertical rotation shaft for carrying out technological processes for obtaining cast or sintered materials synthesized in the process of combustion of highly exothermic powder compositions using self-propagating high-temperature synthesis (SHS) methods.

[0004] The prior art includes various installations for obtaining a semi-finished product from a reaction mixture by centrifugal SHS casting and subsequent vacuum induction remelting of the semi-finished products in a copper water-cooled crucible, which ensures the refining of the alloy from gas impurities and modification of the structure by introducing a powder ligature into the melt, consisting of a pressed mixture of aluminum with nanopowder (patents RU 2630157, RU2032496, RU2523049, RU2320744 and others. They describe the use of a centrifugal installation with a charged refractory mold placed on a rotor.

[0005] The closest analogue is the article by V. V. Klubovich, M. M. Kulak, V. G. Samoletov, B. B. Khina, "PRODUCTION OF WEAR-RESISTANT MATERIALS BY THE SHS CASTING METHOD USING CENTRIFUGAL FORCES" (Bulletin of the National Academy of Sciences of Belarus. Series of Physical and Technical Sciences. 2019. Vol. 64, No. 3. Pp. 275-285) [https: / / vestift.belnauka.by / jour / article / download / 452 / 415], which describes a rotary centrifugal casting unit and the compositions of the initial reaction charge based on iron.

[0006] The centrifugal casting unit consists of a centrifuge rotary lever, ignition coil, batch, reactor, diaphragm plate, casting mold, hanging cups, control panel, sliding contacts, electric motor.

[0007] The synthesis was carried out in the setup. The combustion process was initiated when the centrifuge reached a steady rotation speed by applying voltage through sliding contacts to the nichrome ignition spiral. The hole in the bottom of the reactor, which was a graphite glass, was closed with an iron diaphragm plate 0.2-0.3 mm thick.

[0008] The casting mold and reactor were installed in a suspended cup in sequence. The cup was suspended on a rotary lever and the ignition panel was fixed to it, the terminals of which were connected by wires to the transformer through sliding contacts. The centrifuge was set in rotation by an electric motor. When the rotation frequency of the centrifuge reached a given value, the supply voltage was applied to the ignition spiral. The chemical reaction in the charge led to the appearance of molten phases - oxide and metal. The combustion process, spreading throughout the volume of the charge, reached the bottom of the reactor, the diaphragm melted, and the melt flowed into the casting mold.

[0009] After the melt crystallization process was completed, the centrifuge was stopped and the cast part was removed from the mold. To obtain deposited coatings, the melt was poured onto a steel substrate. Synthesis was carried out in air using a centrifugal overload of n = 400.

[0010] The combustion process in the known installation is initiated when the centrifuge reaches a stationary rotation speed, by applying voltage to the nichrome ignition spiral through sliding contacts. An ignition panel is used, the terminals of which are connected by wires to a transformer through sliding contacts, through which the supply voltage is applied to the ignition spiral.

[0011] The disadvantage of the known centrifugal unit is the absence of a laser ignition system and a reaction block cooling system. The absence of these systems does not allow obtaining cast products of increased purity (due to the possible partial entry of the ignition coil and underwater copper wires into the high-temperature melt) and ensuring a controlled cooling rate of the synthesis product melt in order to obtain a given composition of the target synthesis products and microstructure.

[0012] It has been established that the effect of overload (the effect of centrifugal forces) has a comprehensive effect on all stages of the formation of final products in the process of centrifugal SHS casting. At the combustion stage, the overload intensifies the convective mixing of combustion products in the combustion front propagation zone, which leads to an increase in the completeness of the chemical interaction. At the phase separation stage (gravitational separation) of liquid-phase synthesis products, the metal phase (usually the target one) settles due to its higher specific gravity, forming an ingot of target products in the bottom part of the mold, and the slag phase (based on corundum) forms the upper layer (lower specific gravity), which ensures protection of the high-temperature melt of the metal phase from interaction with the oxidizing environment of the air, protecting the metal melt from oxidation in the air.

[0013] To obtain cast materials based on refractory metals (based on W, Mo, Nb, Cr, etc.), highly exothermic SHS compositions of the thermite type are used; as a result of their interaction, ultra-high temperatures (up to 4000 C) are realized in the combustion front. To ensure controlled conditions for the synthesis of such materials, using centrifugal SHS metallurgy methods, it is necessary to set a set overload level and intensive heat exchange of the mold material in order to prevent its melting.

[0014] Therefore, the known installation is used to obtain less refractory materials, in particular, based on the iron-chromium-nickel-carbon system.

[0015] The technical result of the invention is the possibility of implementing the process of synthesis by methods of centrifugal SHS metallurgy of materials and alloys based on refractory metals at a given (controlled) level of overload (centrifugal forces) and intensive heat exchange of the mold material at the stage of formation and crystallization of the melt, which ensures safe (controlled) formation of synthesis products in a refractory form.The specified technical result is achieved due to the fact that a centrifugal unit for obtaining cast materials, including materials based on refractory metals, by methods of centrifugal SHS metallurgy is declared, from a rotary lever of a rotor centrifuge standing on a support base, on the beam of which two symmetrically located rotary baskets with reaction blocks are placed for placing a refractory mold with an exothermic SHS composition, a remotely located computer control panel for the electric motor drive system for ensuring a controlled (specified) speed of rotation of the rotor of the centrifugal unit, a cooling system for a segmented water-cooled shell, in which a copper mold is located, laminated on the inner surface with a refractory component, a laser initiation (ignition) system for SHS compositions and a backup system for initiating compositions with an electric tungsten spiral.In the system of laser initiation of initial compositions, an optical supply of laser radiation is used, installed near the axis of rotation and through a prismatic mirror the beam is refracted onto the surface of the exothermic SHS composition. In the cooling system, the pipes for supplying and discharging water through shut-off valves, a heat exchanger and centrifugal circulation pumps are connected to the tank of the cooling system, connected to the main line of cooling water through a make-up valve. Preferably, a plate heat exchanger of the radiator type is used, and a solution of 30% ethylene glycol with make-up from a chiller is used as a coolant.

[0016] Preferably, an accelerometer is connected to the copper cooling segment of the basket reactor, which is connected to the control system controller. Preferably, a tungsten spiral is connected to the reactor of each basket itself, the contacts of which are brought out to the rotor joint, from where they are connected via a power cable to the power source of the electric ignition, which, in turn, is connected to the power controller of the electric ignition, and it is connected to the controller of the control system.

[0017] In this case, the control system controller is connected to the frequency converter of the asynchronous drive, which is connected to the asynchronous shaft drive.

[0018] The specified design implementation of several systems at once, operating during the rotor rotation process (beam, support unit with shaft, 2 baskets), in this centrifugal SVS-installation (system for regulating and monitoring the rotation speed of the installation's rotor.

[0019] By including an initiation system in the setup, consisting of a laser ignition system and a reactor block cooling system, a unique combination of instrumental capabilities is provided for controlling combustion processes, forming chemical and phase compositions and forming a microstructure. This opens up new possibilities for the synthesis of practically in-demand materials using centrifugal SHS metallurgy methods.

[0020] Control of the specified overload level, use of a laser system for initiating the initial SHS compositions and a reactor block cooling system ensures controlled provision of synthesis parameters, with the aim of increasing the completeness of the chemical interaction of the components in the combustion front, reducing possible losses of synthesis products due to suppression of the spread at the combustion stage of highly exothermic SHS compositions of the thermite type. Thus, the declared centrifugal unit allows implementing an overload level of up to 600g with previously unattainable masses of exothermic compositions burned up to 10 kg.

[0021] Increasing the mass of the mixture being burned increases the time that the synthesis products remain in the molten state. The effect of high overload values ​​with a simultaneous increase in the melt “life” time increases the degree of phase separation of the synthesis products, ensuring an increase in the purity of the final target synthesis products. The use of a laser reaction initiation system allows for synchronous initiation of SHS compositions in symmetrically located reaction blocks, which creates favorable conditions for the operation of the centrifugal unit. In addition, laser initiation increases the purity of the resulting synthesis products.

[0022] When initiating the mixture, the combustion process of SHS compositions is carried out under the influence of a pre-set overload and the acting in-situ SHS. The effect of the overload in the declared installation has a positive comprehensive effect on all stages of the formation of final products in the SHS process.

[0023] Thus, at the stage of cooling of the high-temperature melt and subsequent crystallization, the water-cooled system of the reaction block and high values ​​of the created overload provide intensive heat and mass exchange between the melt and the wall of the refractory mold, which in turn leads to a significant reduction in structural components (down to the submicron and nanoscale level) and the minimization of liquation heterogeneities.

[0024] In general, the combined effect of the influence of overload and high cooling rate of reaction products leads to an increase in the productivity of the synthesis process, a decrease in material losses during combustion, an increase in the quality of the ingot due to a decrease in the concentration of non-metallic inclusions, a decrease in the level of concentration of gas impurities and a minimization of liquation inhomogeneities (equalization of the chemical composition throughout the entire volume of the ingot), which is especially important for heterogeneous and multicomponent alloys, which include refractory metals and their compounds.

[0025] The invention is illustrated by drawings.

[0026] Fig. 1 shows the internal structure of a centrifugal SHS unit.

[0027] Fig. 2 shows the external appearance of the centrifugal SHS installation used for synthesis.

[0028] Fig. 3 shows the appearance of the obtained cast samples (after removal from the mold) of the target alloys Cr-6MoMo (A) and Cr-30Mo-30W (B).

[0029] Fig. 4 shows the micrographs of the structure (SEM) of the obtained alloy sample based on the two-component alloy system Cr-60Mo (A) and Cr-60W (B).

[0030] Fig. 5 shows the operation diagram of the laser ignition system.

[0031] Fig. 6 shows the operation diagram of the cooling system.

[0032] Fig. 7 shows the centrifuge equipment complex.

[0033] Fig. 8 shows the centrifuge equipment complex (side view in close-up section).

[0034] Figure 9 shows a diagram of the centrifuge.

[0035] Fig. 10 shows the air duct of the ventilation manifold of the degassing system.

[0036] Fig. 11 shows an example of a beam structure.

[0037] Fig. 12 shows the structure of the basket.

[0038] Fig. 13 shows the reactor cooling device. Fig. 14 shows the manipulator device.

[0039] Fig. 15 shows the structure of the bed.

[0040] In the drawings: 1 - base of the centrifugal SHS unit, 2 - rotor, 3 - basket for the SHS combustion reactor, 4 - centrifuge electric motor, 5 - reactor cooling supply system, 6 - beam, 7 - accelerometer, 8 - tungsten spiral, 9 - rotor joint, 10 - power supply cable, 11 - electric igniter power source, 12 - electric igniter power controller, 13 - control system controller, 14 - frequency converter of the asynchronous drive, 15 - asynchronous drive, 16 - reactor cooling device, 17 - reactor, 18 - rotary joint for cooling the laser source, 19 - shaft, 20 - plate heat exchanger, 21 - adjustable constant pressure valve, 22 - feed valve, 23 - cooling system tank, 24 - centrifugal circulation pumps, 25 - flow control valve, 26 - cooling system comb, 27 - angular reducer, 28 - reactor cooling rotor joint, 29 - shut-off, 30 - air duct of the ventilation manifold of the degassing system,31 - centrifuge base, 32 - manipulator, 33 - centrifuge room, 34 - branch pipe for connecting to the reactor cooling system, 35 - collectors, 36 - pipelines, 37 - branches, 38 - coolant, 39 - end support, 40 - intermediate support, 41 - horizontal movement guide, 42 - carriage, 43 - horizontal movement cable layer trough, 44 - horizontal movement cable layer, 45 - vertical movement cable layer, 46-base, 47-lower sector, 48-side sector, 49-bracket, 50-support, 51-axis, 52 - centrifuge.

[0041] Implementation of the invention

[0042] The centrifugal unit (see Fig. 1) operates as follows.

[0043] The initial exothermic SHS composition is loaded into a copper reactor with a refractory lining of the inner surface of the copper mold, then the reactor is placed in a basket located on the beam of the centrifugal SHS unit, on the beam 6 there are two baskets 3 with suspended reactors. The reactor is placed in a water-cooled shell of the basket 3 or a segmented cooling structure. The overload level is set by the number of rotor revolutions per unit of time or by accelerometer readings, the system automatically reaches the specified overload level or number of revolutions.

[0044] The SHS process (laser ignition) is initiated, and then combustion (from several seconds to tens of seconds) of the composition occurs under the conditions of the specified overload effect. Rotation of rotor 2 continues until crystallization of the synthesis products (1-5 minutes, depending on the mass and type of the mixture being burned). Then rotor 2 stops, and after cooling of the reactor, it is removed from the water-cooled shell of basket 3 or segment cooling structure. The metal ingot and slag are removed from the reactor, with their subsequent separation. The lining in the reactor is restored to prepare it for reuse.

[0045] The initiation of the SHS synthesis process occurs using a laser ignition system (Fig. 5) and a backup ignition system based on an electric coil (operating according to the same scheme as in Fig. 5).

[0046] An accelerometer 7 is connected to the copper cooling segment of the reactor cooling device 16 of the reactor basket 3, which is connected to the control system controller 13.

[0047] A tungsten spiral 8 is connected to the reactor of each basket 3, the contacts of which are brought out to the rotor connection 9, from where they are connected via a power supply cable 10 to the power source 11 of the electric ignition, which, in turn, is connected to the power controller of the electric ignition 12, and it is connected to the controller of the control system 13.

[0048] In this case, the controller of the control system 13 is connected to the frequency converter 14 of the asynchronous drive, connected to the asynchronous drive 15 of the shaft 19 (see Fig. 6).

[0049] Laser ignition is performed through an optical supply of laser radiation installed near the rotation axis, and through a prismatic mirror the beam is refracted onto the surface of the exothermic SHS composition. The lasers are powered through the centrifuge shaft (due to a generator operating from the rotation of shaft 19).

[0050] The equipment of the centrifuge complex (see Fig. 7) ensures the following operations: - loading reactors with heated reaction mixture into the centrifuge baskets;

[0051] - acceleration of the centrifuge to a given rotation speed;

[0052] - sending a command to turn on the laser to ignite the reaction mixture;

[0053] - centrifugation until the mixture is completely burned out and separated under the influence of overload on metal and slag;

[0054] - reactor cooling;

[0055] - stop the centrifuge;

[0056] - unloading reactors with metal and slag from the centrifuge baskets.

[0057] Centrifuge 52 is located for safety purposes inside a special room 33 above the floor level. Centrifuge base 31 is fixed to a concrete foundation by means of foundation bolts with nuts. The centrifuge drive is an electric motor 4, which is located in the bin below the floor level.

[0058] The centrifuge rotor is double-armed and is a beam 6 with two baskets 3 for reactors 17, hinged at opposite ends. Baskets 3 are equipped with water-cooled supports (see Fig. 15).

[0059] From above, room 33 of centrifuge 52 is closed by a steel ceiling 29 with two loading hatches equipped with pneumatic drives.

[0060] For transportation, loading and unloading of reactors 17 with reactive mixture, a manipulator 32 with gripping, vertical and horizontal movement functions is provided. Manipulator 32 is mounted on the ceiling 29 of the room.

[0061] To remove combustion products of the reaction mixture from the centrifuge room, air duct 30 of the ventilation manifold of the degassing system is mounted on the walls (see Fig. 10).

[0062] The centrifuge operating procedure is as follows: a) alternate loading of reactors with heated reaction mixture through open hatches of the ceiling by the manipulator into baskets; b) closing of loading hatches; c) acceleration of the centrifuge to a given rotation speed; d) giving a command to turn on the degassing system in the process of the centrifuge reaching the operating speed; d) giving a command to turn on the laser for ignition of the reaction mixture; e) centrifugation until complete combustion of the mixture and its separation under the influence of overload on metal and slag; g) stopping of the centrifuge and positioning; h) giving a command to turn off the degassing system; i) opening of loading hatches; j) alternate unloading of reactors with metal and slag from the centrifuge baskets.

[0063] The centrifuge is designed to create a given overload value required to separate the reaction mixture into metal and slag during combustion.

[0064] The reactor cooling system is shown in Fig.9.

[0065] The body of the base 31 of the centrifuge is the supporting structure of the centrifuge 52 and is designed to withstand loads and transfer them to the foundation.

[0066] In the body of the base 31 of the centrifuge, a vertical hollow shaft is installed on bearings to transmit torque from the drive to the working element.

[0067] Beam 6 of the centrifuge (Fig. 11) is intended for the hinged fastening of baskets 3 and is a spatial metal structure.

[0068] The beam elements 6 are made of high-strength steel and are connected to each other by means of high-strength bolts, nuts and washers.

[0069] In the center of the structure there is a hub for connection with the vertical shaft of the support base 31.

[0070] At the ends of beam 6, there are attachment points for baskets 3. The axes of the attachment points are hollow and equipped with special connections for supplying and removing cooling liquid 38.

[0071] Baskets 3 are designed to accommodate reactors 17 with a reactive mixture and to prevent overheating of the reactor vessels during the combustion reaction of the reactive mixture.

[0072] The structure of the basket is shown in Fig.12.

[0073] Basket 3 is a housing with a reactor cooling device 16 placed inside.

[0074] The elements of the basket body 3 are made of high-strength steel and are connected to each other by means of high-strength bolts, nuts and washers.

[0075] The reactor cooling device 16 includes a support (see Fig. 15), collectors 35 (see Fig. 13), pipelines 36, pipes 37 for supplying / discharging cooling liquid 38, as well as fittings and sleeves of various lengths.

[0076] The support according to Fig. 15 consists of eight lower 47 and eight lateral 48 sectors, located around the circumference and pivotally secured by means of brackets 49, supports 50, axles 51 and fasteners.

[0077] Sectors 47 and 48 are made of copper and have external fins for air cooling and a system of internal channels for liquid cooling.

[0078] Fig.10 shows the air duct of the degassing system.

[0079] It is designed to remove combustion products of the reaction mixture from the centrifuge room.

[0080] The components of the air duct are made of corrosion-resistant heat-resistant steel and are connected to each other using bolts and nuts.

[0081] Manipulator 32 is designed for transporting, loading and unloading reactors with a reactive mixture, and has the functions of gripping, vertical and horizontal movement.

[0082] The manipulator device is shown in Fig.14.

[0083] Manipulator 32 includes the following components:

[0084] - end supports 39;

[0085] - intermediate supports 40;

[0086] - horizontal movement guide 41;

[0087] - carriage 42;

[0088] - horizontal movement cable layer trough 43;

[0089] - horizontal cable layer 44;

[0090] - vertical cable layer 45;

[0091] - pneumatic equipment;

[0092] - electrical equipment. And the end supports 39 and intermediate supports 40 are attached to the concrete surface with anchors.

[0093] On supports 39 and 40, a horizontal movement guide 41 is installed, which is a beam made of a square steel profile with guides for the carriage rollers and a toothed rack installed along its length.

[0094] The body of the carriage 42 is a steel plate on which the components of the horizontal and vertical movement and gripping mechanisms are mounted.

[0095] The horizontal movement mechanism includes four rollers, a gear motor, as well as a toothed rack and guides mounted on a horizontal guide beam.

[0096] The vertical movement mechanism includes four rollers, a gear motor with a gear on a low-speed shaft, as well as a toothed rack and guides mounted on a vertical guide beam.

[0097] An example of the operation of the claimed installation for producing the Cr-Mo-W alloy is described below.

[0098] To obtain a three-component Cr-Mo-W alloy, molybdenum (VI) oxide and tungsten (VI) oxide are simultaneously introduced into the initial composition of the mixture, and to obtain a two-component Cr-Mo or Cr-W, one of the oxides of the target element is used.

[0099] In this case, at least one of the following is used as a refractory form placed on the rotor of the centrifugal unit: alundum, perclase, graphite with an internal lining of aluminum oxide.

[0100] A reaction mixture of the starting components is prepared in the following ratio, mass%: chromium (III) oxide - 28.8; molybdenum (VI) oxide - 44.1; aluminum metal - 26.6; calcium difluoride (CaF2) - 0.7.

[0101] Then the prepared mixture is poured into a refractory form and placed in a centrifugal unit. The centrifuge rotor is set in rotation by an electric drive and at the specified rotor values, providing an overload of 45 g, the reaction mixture is ignited by applying a short pulse of direct current to the electric coil.

[0102] The synthesis is carried out with a steady rotation of the rotor, ensuring the effect of a given value of centrifugal acceleration (overload) on the sample, while the mass of the mixture placed in the mold can vary from 2.5 kg to 8.0 kg, but should not be less than 2.2 kg.

[0103] The essence of the operating principle of the installation consists in using the thermal energy released during the course of exothermic reactions in the combustion wave after the initiation of the mixture of initial reagents. As a result of the implementation of high temperatures directly in the combustion wave, the synthesis process is short-term and takes several tens of seconds. Synthesis in a centrifugal installation can be carried out in atmospheric air. The appearance of a centrifugal SHS installation, with the help of which synthesis can be carried out according to this example, is shown in Fig. 2.

[0104] The initial exothermic SHS composition is loaded into a copper reactor with a refractory lining, then the reactor is placed in a basket located on the beam of the centrifugal SHS unit, on the beam there are baskets with suspended reactors 3, which are symmetrically installed on the beam, the center of which is located on the axis of the rotor 2. The rotor 2 itself is fixed on the base 1 of the SHS unit. Reactors 3 are placed in a water-cooled shell of the basket or a segmented cooling structure. The overload level is set by the number of revolutions of the rotor 2 per unit of time or by the accelerometer readings, the system automatically reaches the specified overload level or number of revolutions.

[0105] The initiation of the SHS process (laser ignition) and then combustion (from several seconds to tens of seconds) of the composition occurs under the conditions of a given overload effect. Rotation of the rotor 2 continues until the crystallization of the synthesis products (1-5 minutes). Then the rotor 2 stops, and after cooling, the reactors 3 are removed from the water-cooled shell of the basket or segmental cooling structure. The metal ingot and slag are removed from the reactors 3. The lining in the reactors 3 is restored to prepare them for reuse.

[0106] Fig. 3 shows the appearance of the obtained cast samples (after removal from the mold) of the target alloys Cr-6MoMo (a) and Cr-30Mo-30W (b).

[0107] Fig. 4 shows the fine-grained structure of the dendritic alloy, which is typical for cast materials. It is evident that the alloy has a uniform structure.

[0108] Microanalysis of the obtained compositions for different sections (top, bottom, middle) did not reveal any noticeable differences in the alloy composition, which is primarily explained by the features of SHS metallurgy and the effect of centrifugal forces, which contribute to more complete mixing of the melt components before its crystallization.

[0109] The results of X-ray phase analysis of the synthesized alloys showed the presence of peaks of a solid solution formed on the basis of target elements (solid solution of Mo and / or W and Cr).

[0110] After the combustion process is complete, the synthesis product is cooled and removed from the reaction mold. The synthesis product consists of two layers with a clear boundary: the lower one is the target Cr-Mo-W alloy and the upper one is a cast oxide material based on Al2O3 (corundum). The layers are easily separated from each other. The content of elements in the target product is wt.%: Mo - 60.2; Al - 0.2; Cr - the rest. Examples of obtaining the specified Cr-Mo-W alloy on the declared installation are presented in Table 1.

[0111] The properties of the target material for the examples are presented in Table 2.

[0112] Table 1. Composition of the reaction mixture of components, wt.%

[0113] Table 2. Characteristics of ingots of the target product Cr-Mo-W alloy.

[0114] As can be seen from the presented data, the proposed method allows obtaining both a two-component and a three-component cast alloy Cr-Mo-W, containing Mo in the range from 0 to 60.2 wt. % and W in the range from 0 to 59.8 wt. %. The effect of overload during combustion leads to intensive mixing of the melt and to a homogeneous distribution of components in the alloy (absence of liquation), a decrease in the content of impurities (non-metallic inclusions) and an increase in the yield of the target alloy to 97% of the calculated values ​​due to the positive effect of centrifugal force on the phase separation of combustion products into a metallic and slag phase.

[0115] Thus, the synthesis using the claimed installation is highly safe, does not require large energy costs, is environmentally friendly due to the absence of gaseous products in the synthesis products, and the resulting target alloy has a high level of uniform distribution of components by volume with a low content of impurities. Since the main technological stage (SHS) is single-stage and its duration does not exceed 1-2 minutes, and the low level of overload allows the use of centrifuge designs with high productivity, the claimed installation has good efficiency.

[0116] Examples of synthesis products produced according to the declared installation:

[0117] 1. Phases of the AZV type with a cubic crystal lattice L12 (NisAl, NisSi, NisFe, NisMn, ZrsAl).

[0118] 2. Phases of the АЗВ type with a hexagonal lattice DO19 (Т1зА1, TbSn).

[0119] 3. Aluminides of the MesAl (AZB) type with a structure different from L12 and DO19 (esAlO3; Nb3Al-0Ah3).

[0120] 4. Aluminides of the MeAl3 type (NbAl3, NiAl3, TaAl3, TiAl3, ZrAl3), their crystal structures are different.

[0121] 5. Phases of type AB with LIO crystal lattice (TiAl, CuAu).

[0122] 6. Phases of type AB with a B2 crystal structure (NiAl, CoTi, CoZr, NiBe, FeAl, FeCo, TiNi).

[0123] 7. Ternary aluminides with the L12 structure: All-x-yTixMey (Me = Co, Cr, Cu, Fe, Mn, Ni; x = 0.24...0.28; y = 0.08...0.14).

[0124] 8. Ternary Laves phases (TiCri,5SiO,5; TaFeAl; TaNiAl; NbNiAl).

[0125] 9. Silicides (MoSi2; NbSi2; Ni3Si; TiSi2; TiSSis; Mg2Si; CoSi2).

[0126] The operating algorithm of the laser ignition system or backup ignition and overload is shown in the following example.

[0127] The operator enters the overload setting and the ignition time after reaching the overload.

[0128] The centrifuge with the reaction mass loaded into the reactor begins to rotate, and under the influence of overload the baskets move into a horizontal position.

[0129] After lifting baskets 3 to a horizontal position and fixing the overload setting on the accelerometer, the laser ignition system of the reaction mixture is activated (laser operating time from 5 to 60 seconds) or the backup ignition system of the reaction mixture (system operating time up to 10 seconds).

[0130] The centrifuge continues to rotate at the set overload during the fusion reaction for about 60 seconds, and then for 360 seconds for final phase separation and crystallization.

[0131] After completion of the synthesis reaction and crystallization of the mass, the centrifuge goes into stop mode.

[0132] The centrifuge must stop in a strictly defined position, in the segment with the loading / unloading hatch.

[0133] Cooling of the reactor shell or system cooling structure is carried out through the centrifuge shaft using a cooling system (Fig. 6).

[0134] In the cooling system (Fig. 6), the copper cooling segment 16 of the reactor 17 of each basket 3 is connected at the bottom to the supply of cooling liquid, and at the top to the outlet of heated liquid.

[0135] The shaft 19 in the upper part of the rotor has a rotor connection 18 for cooling the laser source, also connected to the supply of cooling liquid and the discharge of heated liquid.

[0136] In the lower part of the shaft 19, an angular gearbox 27 and a rotor connection 28 for cooling the reactors are installed.

[0137] The angular gearbox 27 is connected to the asynchronous drive 15 of the shaft 19.

[0138] And the rotary connection 28 for cooling the reactors is also connected to the supply of cooling liquid and the removal of heated liquid.

[0139] All coolant inlets and outlets for heated liquid are routed through the cooling system comb 26, which has shut-off valves for flow control valves 25, as well as pressure and temperature sensors.

[0140] From the cooling system comb 26, the coolant inlets and the heated liquid outlets are fed into the cooling system tank 23, from where the coolant is fed into the cooling system under the pressure of the centrifugal circulation pumps 25. When the pressure in the system drops or increases, it is regulated by the constant pressure valve 21 and the feeder valve 22, which limits the water supply from the main line into the cooling system tank 23.

[0141] The principle of operation of the cooling system is as follows.

[0142] Cooling water enters through make-up valve 22 into cooling system tank 23.

[0143] Centrifugal circulation pumps 25 supply water to the circulation circuit, where it passes through a plate heat exchanger 20 and a constant pressure control valve 21.

[0144] Plate heat exchanger 20 is cooled by a 30% ethylene glycol solution from the chiller.

[0145] Water from the constant pressure circuit enters through the flow control valve 25 to the cooling system comb 26.

[0146] By means of manual regulation and flow adjustment, water is supplied to the rotary connection 28 for cooling the reactors of shaft 19.

[0147] From the rotor joints 28 of the shaft 19, water enters the copper cooling segments 16 of the reactor 17 and for cooling the laser source.

[0148] Water enters the cooling system tank 23 through rotary joints 18, in which cooling water is accumulated for the periodic process of self-propagating high-temperature synthesis.

[0149] Based on the above, it can be concluded that the declared centrifugal unit can be implemented in practice with the achievement of the declared technical result, i.e. it provides a significant increase in the quality of the final SHS products, helps to reduce man-made emissions (increases the environmental friendliness of the SHS process) and increases the efficiency of the process of obtaining new materials by methods of centrifugal SHS metallurgy.

[0150] The installation has been tested. The technical characteristics of the experimental centrifugal SHS installation were measured and are given in Table 3.

[0151] Table 3.

Claims

FORMULA 1. A centrifugal unit for producing cast materials, including materials based on refractory metals, using centrifugal SHS metallurgy methods, from a rotary centrifuge pivoting arm standing on a support base, on the beam of which two symmetrically located pivoting baskets with reaction blocks are placed for accommodating a refractory mold with an exothermic SHS composition, a remotely located computer control panel for the electric motor drive system to ensure a controlled (specified) speed of rotation of the rotor of the centrifugal unit, a cooling system for a segmented water-cooled shell in which a copper mold is located, laminated on the inner surface with a refractory component, a laser initiation (ignition) system for SHS compositions and a backup system for initiating compositions with an electric tungsten spiral;in the laser initiation system of the initial compositions, an optical supply of laser radiation is used, installed near the axis of rotation and through a prismatic mirror the beam is refracted onto the surface of the exothermic SHS composition; in the cooling system, the pipes for supplying and discharging water through shut-off valves, a heat exchanger and centrifugal circulation pumps are connected to the tank of the cooling system, connected to the cooling water main through a make-up valve.

2. A centrifugal unit according to item 1, characterized in that it uses a radiator-type plate heat exchanger, and a 30% ethylene glycol solution with make-up from a chiller is used as a heat carrier.

3. A centrifugal unit according to item 1, characterized in that an accelerometer is connected to the copper cooling segment of the basket reactor, which is connected to the control system controller.

4. A centrifugal unit according to item 1, characterized in that a tungsten spiral is connected to the reactor of each basket, the contacts of which are brought out to the rotor joint, from where they are connected via a power cable to the power source of the electric ignition, which, in turn, is connected to the power controller of the electric ignition, and it is connected to the system controller management.

5. A centrifugal unit according to item 4, characterized in that the control system controller is connected to a frequency converter of an asynchronous drive associated with an asynchronous shaft drive.

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