A lost foam manufacturing process for a superalloy vane shell casting

Abstract

The present application relates to a kind of high-temperature alloy vortex shell castings' investment casting process.The present application includes providing inner circle water-soluble core and outer circle water-soluble core, the inner circle water-soluble core is provided with inner circle positioning core head, the outer circle water-soluble core is provided with outer circle positioning core head;Provide main mould, the main mould includes lower cover plate, movable block assembly;Predetermined number of the inner circle water-soluble core and the outer circle water-soluble core are placed in the main mould respectively by corresponding positioning groove, each the inner circle water-soluble core and each the outer circle water-soluble core are respectively used to form the inner circle runner and outer circle runner of vortex shell runner;Press main body wax mould, form main body wax mould;The main body wax mould is placed in citric acid solution, until each the inner circle water-soluble core and each the outer circle water-soluble core are completely removed, so that the inner circle runner and outer circle runner are formed in the main body wax mould.The present application can significantly improve the size precision and surface quality of casting.

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloy investment casting technology, and in particular to an investment casting process for high-temperature alloy vortex shell castings. Background Technology

[0002] The vortex casing of an aero-engine is a crucial component of the hot-end parts of the engine. Its complex structure typically comprises inner and outer hollow blades, with precise airflow channels formed between them. The dimensional accuracy and surface quality of the vortex casing directly affect the engine's aerodynamic performance and operating efficiency.

[0003] Investment casting (also known as lost-wax casting) is the main process for manufacturing castings with complex structures. For castings with complex internal flow channels, cores are usually required to form the internal cavities. Water-soluble cores, as a type of soluble core, have advantages such as easy core removal and no damage to the casting, and are widely used in investment casting.

[0004] Traditional water-soluble core positioning methods use a core-head splicing approach, where multiple water-soluble cores are joined together at their core heads to form a single unit, which is then placed into a mold for positioning. This method has the following problems: First, there is the problem of accumulated splicing errors. Since each water-soluble core has certain dimensional tolerances in its manufacturing, the errors will accumulate gradually after multiple cores are spliced ​​together, resulting in overall dimensional deviations that are difficult to meet the high precision requirements of aero-engine castings.

[0005] Second, there is the issue of defects at the joints. Defects such as misalignment, flash, and gaps are prone to occur at the joints of the core heads. These defects can transfer to the surface of the casting runner, affecting the surface quality and aerodynamic performance of the runner.

[0006] Third, the assembly process is difficult and inefficient. Multiple water-soluble cores need to be spliced ​​and aligned one by one, which is a complex assembly process that requires high skill from operators and results in low production efficiency.

[0007] Fourth, the pass rate is low and the cost is high. Due to dimensional deviations and surface defects, the pass rate of castings is low, the rework cost is high, and it is not conducive to mass production.

[0008] Therefore, there is an urgent need to develop a new water-soluble core positioning method to solve the problems of dimensional deviation and surface defects in the traditional core splicing method, and to improve the dimensional accuracy and surface quality of aero-engine vortex shell castings. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is to overcome the problems of error accumulation, surface defects at the splicing point, and low assembly efficiency caused by splicing multiple water-soluble cores through core head splicing in the prior art.

[0010] To solve the above technical problems, the present invention provides an investment casting process for high-temperature alloy vortex shell castings, comprising: An inner water-soluble core and an outer water-soluble core are provided. The inner water-soluble core is provided with an inner positioning core head, and the outer water-soluble core is provided with an outer positioning core head. A main mold is provided, the main mold including a lower cover plate and a movable block assembly, the lower cover plate being provided with positioning grooves that respectively cooperate with the inner ring positioning core and the outer ring positioning core; A predetermined number of inner ring water-soluble cores and outer ring water-soluble cores are placed in the main mold through the corresponding positioning grooves. First, multiple inner ring water-soluble cores are placed circumferentially, then multiple outer ring water-soluble cores are placed circumferentially. After the ceramic core is inserted into an adjacent outer ring water-soluble core, the movable block assembly is assembled with the inner ring water-soluble cores, outer ring water-soluble cores and the lower cover plate. Each inner ring water-soluble core and each outer ring water-soluble core is used to form the inner ring flow channel and outer ring flow channel of the vortex shell flow channel, respectively. Press the main wax mold, and inject wax material into the main mold through the wax injection channel on the main mold to form a main wax mold covering each of the inner ring water-soluble cores and each of the outer ring water-soluble cores; The main wax mold is placed in a citric acid solution until each of the inner and outer water-soluble cores is completely removed, thereby forming inner and outer flow channels within the main wax mold.

[0011] In one embodiment of the present invention, an inner water-soluble core and an outer water-soluble core are provided, comprising: A water-soluble core mold is provided, wherein the water-soluble core mold is provided with a first cavity for forming the inner ring water-soluble core and a second cavity for forming the outer ring water-soluble core; Using the aforementioned water-soluble core mold, water-soluble wax material is used to press out the inner ring water-soluble core and the outer ring water-soluble core respectively.

[0012] In one embodiment of the present invention, when pressing the inner ring water-soluble core and the outer ring water-soluble core, the temperature of the water-soluble wax is 65℃~67℃, the injection time is 15s~20s, the holding time is 20s~30s, the temperature of the upper mold plate and the temperature of the lower mold plate of the wax pressing machine are both 15℃~25℃, and the injection pressure is 15bar~20bar. After the inner and outer water-soluble cores are pressed, they should be allowed to cool naturally for at least 3 hours and the surface burrs should be trimmed.

[0013] In one embodiment of the present invention, the live block assembly includes: The first movable block, and a plurality of the first movable blocks are arranged sequentially on the lower cover plate along the circumference of the main mold; The second live block is provided with two radially opposite ones, and the second live block is located between adjacent first live blocks; The central positioning block is positioned on each of the inner ring water-soluble cores and each of the outer ring water-soluble cores; The pressure block assembly includes multiple positioning pressure blocks stacked on top of the central positioning block; The third movable block has a semi-circular structure and two radially opposite parts; the first movable block, the second movable block and the third movable block together define a space for accommodating the inner water-soluble core, the outer water-soluble core and the ceramic core, and the top surface of the third movable block is provided with a flow channel hole.

[0014] In one embodiment of the present invention, an arc-shaped positioning step is provided on the outer side of each of the first movable blocks; Each of the second movable blocks is provided with a positioning top surface and positioning steps provided on both sides in the circumferential direction; One of the positioning blocks has positioning ears at both radial ends; The third movable block is provided with a first positioning part that cooperates with the arc-shaped positioning step, a second positioning part that cooperates with the positioning top surface, a third positioning part that cooperates with the positioning step, and a fourth positioning part that cooperates with the positioning ear.

[0015] In one embodiment of the present invention, each of the inner ring water-soluble cores is provided with a first top surface positioning core head at one end relative to the inner ring water-soluble core, and the outer ring water-soluble core is provided with a second top surface positioning core head at one end relative to the outer ring positioning core head; the end face of the central positioning block is provided with a groove portion that cooperates with the first top surface positioning core head and the second top surface positioning core head.

[0016] In one embodiment of the present invention, a plurality of positioning grooves extending radially outward from the center are distributed circumferentially along the lower cover plate. The outer ends of the first movable block and / or the second movable block are connected to positioning plates. The positioning plates are adapted to be positioned in the positioning grooves and are connected to operating handles.

[0017] In one embodiment of the present invention, the main mold further includes an upper cover plate and a side support plate. The side support plate is arranged around the circumferential outer side of the two third movable blocks. The upper cover plate is positioned on the upper end of the side support plate. A wax injection channel communicating with the flow channel hole is provided between the upper cover plate and the side support plate.

[0018] In one embodiment of the present invention, one of the third movable blocks is provided with a positioning hole, and the other third movable block is provided with a positioning pin that cooperates with the positioning hole; The upper end of the side support plate is provided with an arc-shaped positioning boss, and the bottom end of the upper cover plate is provided with an arc-shaped positioning groove that cooperates with the arc-shaped positioning boss.

[0019] In one embodiment of the present invention, when pressing the main wax mold, the temperature of the filling wax is 65℃~67℃, the injection time is 20s~25s, the holding time is 25s~35s, the temperature of the upper mold plate and the temperature of the lower mold plate of the wax pressing machine are both 20℃~30℃, and the injection pressure is 9bar~15bar.

[0020] The technical solution of the present invention has the following advantages compared with the prior art: The investment casting process for a high-temperature alloy vortex shell casting described in this invention employs a method of individual core head positioning for each water-soluble core. The positional accuracy of each water-soluble core is directly guaranteed by the positioning structure of the mold, eliminating the error accumulation problem of traditional splicing methods and improving the flow channel dimensional accuracy by more than 50%.

[0021] This invention eliminates the splicing interface between water-soluble core heads, preventing misalignment, flash, and gaps at the splicing points from transferring to the surface of the casting runner, thereby improving the surface quality of the runner. Under the same production conditions, the dimensional accuracy of the runner can be improved by more than 50%, and the surface roughness can be reduced by 1 to 2 grades.

[0022] This invention adopts an independent placement method for water-soluble cores, eliminating the need to splice and align multiple water-soluble cores. This simplifies assembly operations, reduces reliance on operator skills, and increases production efficiency by more than 30%.

[0023] This invention can reduce rework and scrap caused by dimensional deviations and surface defects in the flow channel, improve the casting qualification rate, significantly reduce dimensional deviations and surface defects, significantly improve the casting qualification rate, reduce rework costs, and is suitable for mass production.

[0024] This invention has a wide range of applications, not only applicable to vortex shell castings for aero-engines, but also applicable to other investment castings with complex internal flow channels. Attached Figure Description

[0025] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0026] Figure 1 This is a flowchart of the investment casting process for high-temperature alloy vortex shell castings.

[0027] Figure 2 This is a schematic diagram of the structure of a high-temperature alloy vortex shell casting.

[0028] Figure 3 This is a cross-sectional schematic diagram of the flow channel area of ​​a high-temperature alloy vortex shell casting.

[0029] Figure 4 This is a schematic diagram of the inner and outer water-soluble cores.

[0030] Figure 5 This is a schematic diagram of the exploded structure of a water-soluble core mold.

[0031] Figure 6 This is a schematic diagram of the overall structure of the main mold.

[0032] Figure 7 This is a partial exploded structural diagram of the main mold.

[0033] Figure 8 This is a schematic diagram showing the positions of the inner and outer water-soluble cores in the main mold.

[0034] Figure 9 This is a structural schematic diagram of the lower cover plate.

[0035] Figure 10 This is a partial structural diagram of the main mold. Figure 1 .

[0036] Figure 11 This is a partial structural diagram of the main mold. Figure 2 .

[0037] Figure 12 This is a partial structural diagram of the main mold. Figure 3 .

[0038] Figure 13 This is a partial structural diagram of the main mold. Figure 4 .

[0039] Figure 14 This is a partial structural diagram of the main mold. Figure 5 .

[0040] Figure 15 This is a structural diagram of the third live block.

[0041] Figure 16 This is a structural diagram of the central positioning block.

[0042] Figure 17 This is a structural diagram of the top cover plate.

[0043] Explanation of reference numerals in the instruction manual: 1. Inner ring water-soluble core; 11. Inner ring positioning core head; 12. First top surface positioning core head; 2. Outer ring water-soluble core; 21. Outer ring positioning core head; 22. Second top surface positioning core head; 3. Main mold; 30. Wax injection runner; 31. Lower cover plate; 311. Positioning groove; 312. Positioning slot; 32. Movable block assembly; 33. First movable block; 331. Arc-shaped positioning step; 332. Positioning plate; 333. Operating handle; 34. Second movable block; 341. Positioning top surface; 342. Positioning step; 35. Center positioning block; 351. Groove; 36. Positioning pressure block; 361. Positioning ear; 37. Third movable block; 371. Flow channel hole; 372. First positioning part; 373. Second positioning part; 374. Third positioning part; 375. Fourth positioning part; 376. Positioning hole; 377. Positioning pin; 38. Top cover plate; 381. Arc-shaped positioning groove; 39. Side support plate; 391. Arc-shaped positioning boss; 4. Ceramic core; 5. Main body wax model; 6. Vortex shell; 61. Inner flow channel; 62. Outer flow channel; 7. Water-soluble core mold; 71. First cavity; 72. Second cavity. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0045] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0046] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0047] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0048] Reference Figure 1As shown, a high-temperature alloy vortex shell casting investment casting process includes: S1, Water-soluble core mold design. (Refer to...) Figure 4 As shown, an inner water-soluble core 1 and an outer water-soluble core 2 are provided. The inner water-soluble core 1 is provided with an inner positioning core head 11, and the outer water-soluble core 2 is provided with an outer positioning core head 21. (Refer to...) Figure 5 As shown, it specifically includes: A water-soluble core mold 7 is provided, wherein the water-soluble core mold 7 is provided with a first cavity 71 for forming the inner ring water-soluble core 1 and a second cavity 72 for forming the outer ring water-soluble core 2; Using the water-soluble core mold 7, water-soluble wax is used to press out the inner ring water-soluble core 1 and the outer ring water-soluble core 2 respectively.

[0049] Reference Figure 3 and Figure 4 A water-soluble core mold 7 is configured with one inner ring water-soluble core 1 cavity and two outer ring water-soluble core 2 cavities, so that each pressing can produce one inner ring water-soluble core 1 and two outer ring water-soluble core 2. The inner ring water-soluble core 1 and the outer ring water-soluble core 2 are integrally pressed and formed.

[0050] Specifically, during the water-soluble core pressing process, the water-soluble core mold 7 is installed on a 25T wax press. The temperature of the water-soluble wax is set to 65℃~67℃, the injection time to 15s~20s, the holding time to 20s~30s, the temperature of both the upper and lower mold plates of the wax press to 15℃~25℃, and the injection pressure to 15bar~20bar. These parameters ensure that the water-soluble wax fully fills the first cavity 71 and the second cavity 72, while reducing defects such as insufficient material, air holes, or shrinkage inside the water-soluble core. After pressing, the inner water-soluble core 1 and the outer water-soluble core 2 are allowed to cool naturally for at least 3 hours to allow the water-soluble core to fully set, reducing the possibility of bending or deformation during subsequent assembly.

[0051] After cooling, burrs, parting lines, and wax injection ports on the surfaces of the inner ring water-soluble core 1 and the outer ring water-soluble core 2 are trimmed, and the integrity of the inner ring positioning core head 11, the outer ring positioning core head 21, the first top surface positioning core head 12, and the second top surface positioning core head 22 are checked. The qualified inner ring water-soluble core 1 and outer ring water-soluble core 2 are neatly placed for subsequent pressing of the main body wax model 5.

[0052] S2, Reference Figures 6 to 9 As shown, the main mold 3 includes a lower cover plate 31 and a movable block assembly 32. The lower cover plate 31 is provided with positioning grooves 311 that respectively cooperate with the inner ring positioning core 11 and the outer ring positioning core 21.

[0053] Since each inner ring water-soluble core 1 and each outer ring water-soluble core 2 are individually positioned by the corresponding positioning groove 311, there is no splicing relationship between the water-soluble cores. Therefore, the dimensional error of one water-soluble core will not be transmitted to the adjacent water-soluble cores, thus avoiding the cumulative error caused by the traditional core head series splicing method.

[0054] Specifically, refer to Figures 10 to 14 As shown, the live block assembly 32 includes: The first movable block 33, and a plurality of the first movable blocks 33 are arranged sequentially on the lower cover plate 31 along the circumference of the main mold 3; The second movable block 34 is provided in two radially opposite positions, and the second movable block 34 is located between adjacent first movable blocks 33; The central positioning block 35 is positioned on each of the inner ring water-soluble cores 1 and each of the outer ring water-soluble cores 2; The pressure block assembly includes a plurality of positioning pressure blocks 36 stacked on top of the central positioning block 35; The third movable block 37 has a semi-circular structure and is provided with two radially opposite blocks; the first movable block 33, the second movable block 34 and the third movable block 37 together define a space for accommodating the inner ring water-soluble core 1, the outer ring water-soluble core 2 and the ceramic core 4, and the top surface of the third movable block 37 is provided with a flow channel hole 371.

[0055] Reference Figure 8 As shown, each of the first movable blocks 33 has an arc-shaped positioning step 331 on its outer side; each of the second movable blocks 34 has a positioning top surface 341 and positioning steps 342 on both circumferential sides; refer to Figure 10 As shown, one of the positioning blocks 36 has positioning ears 361 at both radial ends.

[0056] Reference Figure 15 As shown, the third movable block 37 is provided with a first positioning part 372 that cooperates with the arc-shaped positioning step 331, a second positioning part 373 that cooperates with the positioning top surface 341, a third positioning part 374 that cooperates with the positioning step 342, and a fourth positioning part 375 that cooperates with the positioning ear 361.

[0057] The first positioning part 372 cooperates with the arc-shaped positioning step 331 on the outer side of the first movable block 33 to determine the radial and axial positions of the third movable block 37 relative to the first movable block 33.

[0058] The second positioning part 373 cooperates with the positioning top surface 341 of the second movable block 34 to provide axial support for the third movable block 37.

[0059] The third positioning part 374 cooperates with the positioning steps 342 on both sides of the second movable block 34 to restrict the third movable block 37 from moving circumferentially relative to the second movable block 34.

[0060] The fourth positioning part 375 cooperates with the positioning ears 361 at both ends of the positioning block 36 to restrict the movement of the block assembly relative to the third movable block 37 in the radial or circumferential direction.

[0061] Reference Figure 16 As shown, each of the inner ring water-soluble cores 1 has a first top surface positioning core head 12 at one end relative to the inner ring water-soluble core 1, and the outer ring water-soluble core 2 has a second top surface positioning core head 22 at one end relative to the outer ring positioning core head 21; the end face of the center positioning block 35 is provided with a groove portion 351 that cooperates with the first top surface positioning core head 12 and the second top surface positioning core head 22.

[0062] After the inner ring positioning core 11 and the outer ring positioning core 21 are respectively engaged with the positioning groove 311 on the lower cover plate 31, the central positioning block 35 engages with the first top surface positioning core 12 and the second top surface positioning core 22 through the groove portion 351, enabling positioning of each inner ring water-soluble core 1 and each outer ring water-soluble core 2 from the upper end of the water-soluble core. Thus, both the upper and lower ends of each water-soluble core are independently positioned, reducing the possibility of the water-soluble core shifting or tilting due to wax injection pressure.

[0063] Reference Figure 8 , Figure 9 As shown, multiple positioning grooves 312 extending radially outward from the center are distributed circumferentially along the lower cover plate 31. Positioning plates 332 are connected to the outer ends of the first movable block 33 and / or the second movable block 34. The positioning plates 332 are adapted to be positioned within the positioning grooves 312, and are connected to operating handles 333. Operators can use the operating handles 333 to push or pull out the corresponding first movable block 33 or second movable block 34 radially along the main mold 3 to facilitate the assembly and disassembly of the main mold 3.

[0064] Reference Figure 17 As shown, the main mold 3 also includes an upper cover plate 38 and a side support plate 39. The side support plate 39 surrounds the two third movable blocks 37 on their circumferential outer sides. The upper cover plate 38 is positioned on the upper end of the side support plate 39. A wax injection channel 30 communicating with the flow channel hole 371 is provided between the upper cover plate 38 and the side support plate 39. Thus, the wax injected by the wax press can sequentially enter the molding space inside the main mold 3 through the wax injection channel 30 and the flow channel hole 371.

[0065] Reference Figure 10 , Figure 15As shown, one of the third movable blocks 37 is provided with a positioning hole 376, and the other third movable block 37 is provided with a positioning pin 377 that cooperates with the positioning hole 376; when the two third movable blocks 37 are assembled, the positioning pin 377 is inserted into the positioning hole 376, thereby ensuring the relative position between the two third movable blocks 37 and preventing misalignment of the splicing position of the two third movable blocks 37.

[0066] Reference Figure 13 , Figure 17 As shown, the upper end of the side support plate 39 is provided with an arc-shaped positioning boss 391, and the bottom end of the upper cover plate 38 is provided with an arc-shaped positioning groove 381 that cooperates with the arc-shaped positioning boss.

[0067] S3. A predetermined number of inner ring water-soluble cores 1 and outer ring water-soluble cores 2 are placed in the main mold 3 through the corresponding positioning grooves 312. First, the inner ring water-soluble cores 1 are placed circumferentially, then the outer ring water-soluble cores 2 are placed circumferentially. After inserting the ceramic core 4 into adjacent outer ring water-soluble cores 2, the movable block assembly 32 is assembled with the inner ring water-soluble cores 1, outer ring water-soluble cores 2, and the lower cover plate 31. Each inner ring water-soluble core 1 and each outer ring water-soluble core 2 is used to form the inner ring flow channel 61 and outer ring flow channel 62 of the vortex shell 6, respectively. The ceramic core 4 is used to form the cavity inside the outer ring hollow blade of the vortex shell 6, and maintains the shape and size of the cavity during the high-temperature alloy casting process. The ceramic core 4 has high-temperature resistance and can maintain its predetermined shape during subsequent shell making, dewaxing, and high-temperature alloy casting processes. It is removed through a core removal process after the casting solidifies, thereby forming a predetermined internal cavity inside the outer ring hollow blade.

[0068] The inner water-soluble core 1 and the outer water-soluble core 2 are independently positioned and fitted with the main mold 3. Adjacent water-soluble cores are not spliced ​​together through the core head, thereby avoiding the accumulation of dimensional errors caused by splicing multiple water-soluble cores together.

[0069] S4. Press the main wax mold 5, and inject wax material into the main mold 3 through the wax injection channel 30 on the main mold 3 to form the main wax mold 5 covering each of the inner ring water-soluble cores 1 and each of the outer ring water-soluble cores 2.

[0070] Specifically, the assembled main mold 3 is installed on a 25T wax press. When pressing the main wax mold 5, the temperature of the filling wax is 65℃~67℃, the injection time is 20s~25s, the holding time is 25s~35s, the temperature of the upper mold plate and the temperature of the lower mold plate of the wax press are both 20℃~30℃, and the injection pressure is 9bar~15bar.

[0071] After the main wax model 5 has cooled and solidified, remove the top cover plate 38 and the side support plate 39, and then separate the two third movable blocks 37 radially. Then, remove the pressure block assembly and the center positioning block 35 in sequence, and pull out the second movable block 34 and each first movable block 33 radially through the operating handle 333. Finally, remove the main wax model 5 from the bottom cover plate 31.

[0072] After removing the main wax model 5, repair the parting line, burrs and wax injection port on the surface of the main wax model 5, and check whether the main wax model 5 has defects such as deformation, missing material, cracks or water-soluble core displacement.

[0073] S5. Place the pressed and inspected main body wax mold 5 into a citric acid solution, so that the citric acid solution comes into contact with the inner water-soluble core 1 and the outer water-soluble core 2 inside the main body wax mold 5.

[0074] The water-soluble wax gradually dissolves in the citric acid solution. During the process, the main wax mold 5 can be flipped or moved appropriately according to the dissolution of the water-soluble cores to promote the citric acid solution to enter the interior of the main wax mold 5 and to ensure that each inner ring water-soluble core 1 and each outer ring water-soluble core 2 dissolves evenly.

[0075] The treatment time of the main wax mold 5 in citric acid solution is determined by the complete removal of each inner ring water-soluble core 1 and each outer ring water-soluble core 2. After the inner ring water-soluble core 1 is removed, an inner ring flow channel 61 corresponding to the shape of the inner ring water-soluble core 1 is formed in the main wax mold 5; after the outer ring water-soluble core 2 is removed, an outer ring flow channel 62 corresponding to the shape of the outer ring water-soluble core 2 is formed in the main wax mold 5.

[0076] After the water-soluble core is completely removed, the main wax mold 5 is taken out of the citric acid solution, and the inside of the main wax mold 5 is cleaned and dried to remove residual water-soluble wax and citric acid solution.

[0077] S6. Based on the reference points of the vortex shell 6 wax model drawing, inspect the inner ring flow channel 61, outer ring flow channel 62, and other key dimensions of the main body wax model 5. When all dimensions of the main body wax model 5 are within the design tolerance range, transfer the main body wax model 5 to the subsequent existing processes such as wax model assembly, shell making, dewaxing, firing, pouring, and core removal to obtain the high-temperature alloy vortex shell 6 casting.

[0078] In one embodiment, five inner ring water-soluble cores 1 and ten outer ring water-soluble cores 2 are used. The five inner ring water-soluble cores 1 are arranged evenly around the central axis of the main mold 3 or at intervals according to the design angle of the inner ring flow channel 61 of the vortex shell 6. When placing each inner ring water-soluble core 1, the inner ring positioning core head 11 at the lower end of the inner ring water-soluble core 1 is inserted into the corresponding positioning groove 311 on the lower cover plate 31, so that each inner ring water-soluble core 1 is independently positioned through the corresponding positioning groove 311. After the inner ring water-soluble cores 1 are placed, the ten outer ring water-soluble cores 2 are placed sequentially along the circumference of the main mold 3. When placing each outer ring water-soluble core 2, the outer ring positioning core head 21 at the lower end of the outer ring water-soluble core 2 is inserted into the corresponding positioning groove 311 on the lower cover plate 31, so that each outer ring water-soluble core 2 is independently positioned through the corresponding positioning groove 311. The inner ring water-soluble cores 1 and the outer ring water-soluble cores 2, as well as adjacent outer ring water-soluble cores 2, are not spliced ​​together by positioning core heads. Each inner ring water-soluble core 1 is used to form the inner ring flow channel 61 of the vortex shell 6, and each outer ring water-soluble core 2 is used to form the outer ring flow channel 62 of the vortex shell 6. After the positioning of the outer ring water-soluble cores 2 is completed, ceramic cores 4 are inserted between adjacent outer ring water-soluble cores 2. Ceramic cores 4 are used to form local cavities or flow channel structures in the vortex shell 6 that cannot be formed by water-soluble cores alone. The number, shape, and installation position of ceramic cores 4 can be determined according to the specific structure of the vortex shell 6 casting.

[0079] Subsequently, multiple first movable blocks 33 are installed sequentially along the circumference of the lower cover plate 31, and the positioning plates 332 of each first movable block 33 are respectively inserted into the corresponding positioning grooves 311 on the lower cover plate 31. Then, two second movable blocks 34 are pushed radially into their corresponding positions, so that the two second movable blocks 34 are respectively located between adjacent first movable blocks 33.

[0080] After the installation of the first movable block 33 and the second movable block 34 is completed, the center positioning block 35 is placed on the upper end of each inner ring water-soluble core 1 and each outer ring water-soluble core 2, so that the multiple grooves 351 on the center positioning block 35 respectively cooperate with the first top surface positioning core head 12 and the second top surface positioning core head 22.

[0081] Multiple positioning blocks 36 are sequentially installed on the upper end of the central positioning block 35, and the positioning block 36 with positioning ears 361 is positioned corresponding to the third movable block 37.

[0082] Then, the two semi-circular third movable blocks 37 are installed from both radial sides, so that the two third movable blocks 37 are joined together. The positioning pin 377 on one of the third movable blocks 37 is inserted into the positioning hole 376 on the other third movable block 37. After the third movable blocks 37 are installed in place, the first positioning part 372 of the third movable block 37 is positioned and engaged with the arc-shaped positioning step 331 of the first movable block 33, the second positioning part 373 abuts against the positioning top surface 341 of the second movable block 34, the third positioning part 374 is positioned and engaged with the positioning steps 342 on both sides of the second movable block 34, and the fourth positioning part 375 is positioned and engaged with the positioning ear 361 on the positioning pressure block 36. Thus, the first movable block 33, the second movable block 34, the central positioning block 35, the pressure block assembly, and the third movable block 37 cooperate with each other to form a multi-directional positioning structure for the inner water-soluble core 1, the outer water-soluble core 2, and the ceramic core 4.

[0083] Subsequently, the side support plate 39 is installed on the circumferential outer side of the two third movable blocks 37, and the upper cover plate 38 is installed on the upper end of the side support plate 39, so that the arc-shaped positioning boss 391 on the side support plate 39 enters the arc-shaped positioning groove 381 at the bottom of the upper cover plate 38.

[0084] After the top cover plate 38, side support plate 39, and movable block assembly 32 are all installed in place, the main mold 3 is closed. At this time, the wax injection channel 30 between the top cover plate 38 and the side support plate 39 is connected to the channel hole 371 on the third movable block 37, and then the subsequent pressing of the main body wax model 5 is carried out.

[0085] The lower end of each inner ring water-soluble core 1 and each outer ring water-soluble core 2 is independently positioned by the positioning groove 312 on the lower cover plate 31, and the upper end of each inner ring water-soluble core 1 and each outer ring water-soluble core 2 is positioned by the center positioning block 35. This positioning method does not require splicing the core heads of multiple water-soluble cores together, which can reduce the assembly error and error accumulation between water-soluble cores, and at the same time avoid misalignment, flash or gaps at the core head splicing position, thereby helping to improve the dimensional accuracy and surface quality of the inner ring flow channel 61 and the outer ring flow channel 62 of the vortex shell 6. Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A process for investment casting of a high-temperature alloy vortex shell, characterized in that, include: An inner water-soluble core (1) and an outer water-soluble core (2) are provided. The inner water-soluble core (1) is provided with an inner positioning core head (11), and the outer water-soluble core (2) is provided with an outer positioning core head (21). A main mold (3) is provided, the main mold (3) includes a lower cover plate (31) and a movable block assembly (32). The lower cover plate (31) is provided with positioning grooves (311) that respectively cooperate with the inner ring positioning core (11) and the outer ring positioning core (21). A predetermined number of inner ring water-soluble cores (1) and outer ring water-soluble cores (2) are placed in the main mold (3) through the corresponding positioning grooves (311). First, multiple inner ring water-soluble cores (1) are placed along the circumference, and then multiple outer ring water-soluble cores (2) are placed along the circumference. After the ceramic core (4) is inserted into the adjacent outer ring water-soluble cores (2), the movable block assembly (32) is assembled with the inner ring water-soluble cores (1), the outer ring water-soluble cores (2) and the lower cover plate (31). Each inner ring water-soluble core (1) and each outer ring water-soluble core (2) is used to form the inner ring flow channel (61) and the outer ring flow channel (62) of the vortex shell flow channel, respectively. Press the main wax mold (5), and inject wax material into the main mold (3) through the wax injection channel (30) on the main mold (3) to form a main wax mold (5) covering each of the inner ring water-soluble cores (1) and each of the outer ring water-soluble cores (2). The main wax mold (5) is placed in a citric acid solution until each of the inner ring water-soluble cores (1) and each of the outer ring water-soluble cores (2) are completely removed, so that an inner ring flow channel (61) and an outer ring flow channel (62) are formed in the main wax mold (5).

2. The investment casting process for a high-temperature alloy vortex shell casting according to claim 1, characterized in that, Provides an inner water-soluble core (1) and an outer water-soluble core (2), including: A water-soluble core mold (7) is provided, wherein a first cavity (71) for forming the inner ring water-soluble core (1) and a second cavity (72) for forming the outer ring water-soluble core (2) are provided in the water-soluble core mold (7). Using the water-soluble core mold (7), water-soluble wax is used to press out the inner ring water-soluble core (1) and the outer ring water-soluble core (2).

3. The investment casting process for a high-temperature alloy vortex shell casting according to claim 2, characterized in that, When pressing the inner water-soluble core (1) and the outer water-soluble core (2), the temperature of the water-soluble wax is 65℃~67℃, the injection time is 15s~20s, the holding time is 20s~30s, the temperature of the upper mold plate and the temperature of the lower mold plate of the wax press are both 15℃~25℃, and the injection pressure is 15bar~20bar. After the inner water-soluble core (1) and the outer water-soluble core (2) are pressed, they are naturally cooled for at least 3 hours and the surface burrs are trimmed.

4. The investment casting process for a high-temperature alloy vortex shell casting according to claim 1, characterized in that, The live block assembly (32) includes: The first movable block (33) and a plurality of the first movable blocks (33) are arranged sequentially on the lower cover plate (31) along the circumference of the main mold (3); The second movable block (34) is provided with two radially opposite ones, and the second movable block (34) is located between the adjacent first movable block (33); The central positioning block (35) is positioned on each of the inner ring water-soluble cores (1) and each of the outer ring water-soluble cores (2); The pressure block assembly includes a plurality of positioning pressure blocks (36) stacked on top of the central positioning block (35). The third movable block (37) has a semi-circular structure and is provided with two radially opposite parts; the first movable block (33), the second movable block (34) and the third movable block (37) together define a space for accommodating the inner ring water-soluble core (1), the outer ring water-soluble core (2) and the ceramic core (4), and the top surface of the third movable block (37) is provided with a flow channel hole (371).

5. The investment casting process for a high-temperature alloy vortex shell casting according to claim 4, characterized in that, Each of the first movable blocks (33) has an arc-shaped positioning step (331) on its outer side; Each of the second movable blocks (34) is provided with a positioning top surface (341) and positioning steps (342) provided on both sides of the circumference. One of the positioning blocks (36) is provided with positioning ears (361) at both radial ends; The third movable block (37) is provided with a first positioning part (372) that cooperates with the arc-shaped positioning step (331), a second positioning part (373) that cooperates with the positioning top surface (341), a third positioning part (374) that cooperates with the positioning step (342), and a fourth positioning part (375) that cooperates with the positioning ear (361).

6. The investment casting process for a high-temperature alloy vortex shell casting according to claim 4, characterized in that, Each of the inner ring water-soluble cores (1) has a first top surface positioning core head (12) at one end relative to the inner ring water-soluble core (1), and the outer ring water-soluble core (2) has a second top surface positioning core head (22) at one end relative to the outer ring positioning core head (21); the end face of the center positioning block (35) has a groove (351) that cooperates with the first top surface positioning core head (12) and the second top surface positioning core head (22).

7. The investment casting process for a high-temperature alloy vortex shell casting according to claim 4, characterized in that, Multiple positioning grooves (312) extending radially outward from the center are distributed circumferentially along the lower cover plate (31). The outer ends of the first movable block (33) and / or the second movable block (34) are connected to positioning plates (332). The positioning plates (332) are adapted to be positioned in the positioning grooves (312). The positioning plates (332) are connected to operating handles (333).

8. The investment casting process for a high-temperature alloy vortex shell casting according to claim 4, characterized in that, The main mold (3) also includes an upper cover plate (38) and a side support plate (39). The side support plate (39) surrounds the two third movable blocks (37) on the circumferential outside. The upper cover plate (38) is positioned on the upper end of the side support plate (39). A wax injection channel (30) communicating with the flow channel hole (371) is provided between the upper cover plate (38) and the side support plate (39).

9. The investment casting process for a high-temperature alloy vortex shell casting according to claim 8, characterized in that, One of the third movable blocks (37) is provided with a positioning hole (376), and the other third movable block (37) is provided with a positioning pin (377) that cooperates with the positioning hole (376). The upper end of the side support plate (39) is provided with an arc-shaped positioning boss (391), and the bottom end of the upper cover plate (38) is provided with an arc-shaped positioning groove (381) that cooperates with the arc-shaped positioning boss (391).

10. The investment casting process for a high-temperature alloy vortex shell casting according to claim 1, characterized in that, When pressing the main wax mold (5), the temperature of the filling wax is 65℃~67℃, the injection time is 20s~25s, the holding time is 25s~35s, the temperature of the upper mold plate and the lower mold plate of the wax press are both 20℃~30℃, and the injection pressure is 9bar~15bar.

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