Internally controlled hot isostatic pressing part forming die and forming method thereof

Abstract

The present invention discloses an internally controlled hot isostatic pressing part forming die and a forming method thereof, belonging to the field of hot isostatic pressing process technology. The forming die includes a circular base block and a forming sleeve. A reserved hole is provided in the center of the circular base block. A core is installed in the reserved hole. A forming cavity is provided between the core, the circular base block, and the forming sleeve. The forming cavity includes an upper powder forming layer and a lower powder forming layer distributed above and below. A control die is provided between the upper and lower powder forming layers. A connection gap is reserved on the control die. A powder filling port connected to the upper powder forming layer is provided on the forming sleeve. The forming method includes: S1, filling powder particles; S2, vacuuming and sealing the powder filling port; S3, performing hot isostatic pressing; S4, removing the circular base block, forming sleeve, control die, and core of the compact to obtain the part; S5, performing trimming and surface treatment to obtain the formed part. The structural compensation design can ensure that the control die is subjected to balanced forces above and below, effectively preventing part warping.

Description

Technical Field

[0001] The invention relates to the technical field of hot isostatic pressing technology, in particular to an internally controlled hot isostatic pressing part forming die and a forming method thereof. Background Art

[0002] Hot isostatic pressing (HIP) is a near-net-shape forming technology that directly sinters powders to a dense, dense state under high temperature and high pressure. It offers advantages such as high material utilization, short production cycles, and excellent overall part performance. It is particularly well-suited for producing parts with high melting points, complex structures, and the joining of dissimilar materials, particularly in technical fields such as aerospace, where high structural and functional requirements are crucial. Compared to casting, HIP produces parts with superior overall performance, free of defects such as segregation and shrinkage. Compared to forging, HIP offers short processing cycles, high material utilization, and the ability to produce parts with complex structures.

[0003] Hot isostatic pressing technology is a forming and preparation technology under isotropic pressure conditions, but for parts that need internal shape control (parts such as accessories Figure 2 As shown), it is affected by the package and the internal control mold (the mold is shown in the attached Figure 6 As shown in the figure, the force inside the powder is not actually isotropic, so the shrinkage of the powder is also uneven. The powder will shrink after hot isostatic pressing. Even if the initial powder density is high, the volume shrinkage will be close to 30% after forming. Therefore, when the powder above the control mold shrinks, the bottom circular base block affects the pressure transmission due to the shielding effect, so that the powder is not subjected to isotropic pressure, causing the control mold to deform upward, and eventually causing the whole part to warp (warped parts are shown in the attached figure). Figure 7 As shown). In order to reduce the warping deformation of parts, the current patents usually optimize the cavity structure and the temperature and pressure curve of the hot isostatic pressing process. For example, the patent number is "CN110666174 A", and the patent name is "Method for Improving the Warping Deformation of the End Face of Hot Isostatic Pressed Powder Metallurgy Flat Components", which includes (1) optimizing the cavity structure of the flat disc-shaped structural component with steps; (2) adjusting the hot isostatic pressing loading process to a process of heating first and then pressurizing. However, the overall structure of the parts in the above patents is relatively simple, and does not require internal shape control, and only optimizes the local accuracy. Therefore, it is not suitable for the forming of parts that require internal shape control. Moreover, for hot isostatic pressing equipment, the method of heating first and then pressurizing is difficult to operate and difficult to implement. In addition, whether it is the existing technology or the above patents, because there will be a certain amount of residual stress inside the formed parts, this will also lead to increased warping deformation of the parts after hot isostatic pressing, making it difficult to meet the shape and position tolerance requirements, increasing the difficulty of mechanical processing to remove the sheath, and in severe cases, it will directly lead to the scrapping of the parts. Summary of the Invention

[0004] The purpose of the present invention is to solve the above-mentioned technical problems and provide an internally controlled hot isostatic pressing part forming mold and a forming method thereof. The forming mold is designed with structural compensation, and the forming cavity is divided into an upper and lower powder forming layer. During the hot isostatic pressing process, the upper and lower powder forming layers shrink synchronously, which can ensure that the upper and lower sides of the controlled mold are subjected to balanced force, and can effectively prevent the parts after hot isostatic pressing from warping.

[0005] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention discloses an internally controlled hot isostatic pressing part forming mold, comprising a circular base block and a forming sleeve covering the circular base block, the forming sleeve and the circular base block are sealed and connected, a reserved hole is provided in the center of the circular base block, a core for supporting and fixing the forming sleeve is installed in the reserved hole, a forming cavity is provided between the core, the circular base block and the forming sleeve, the forming cavity comprises an upper powder forming layer and a lower powder forming layer distributed in an upper and lower manner, a control mold fixed on the core is provided between the upper powder forming layer and the lower powder forming layer, a connection gap is reserved on the control mold to connect the upper powder forming layer and the lower powder forming layer, a powder filling port to be sealed is provided on the forming sleeve, and the powder filling port is connected to the upper powder forming layer.

[0006] Preferably, the thickness of the lower powder molding layer needs to satisfy h≥1 / 2H, where h is the thickness of the lower powder molding layer and H is H of the thickness of the upper powder molding layer.

[0007] Preferably, the core is a tubular core, and the wall thickness of the tubular core needs to satisfy 1 / 10L≤t≤3 / 10L, where t is the wall thickness of the tubular core, and L is the radius of the circular base block minus the radius of the tubular core.

[0008] Preferably, a connecting hole is provided in the middle of the molding sleeve for inserting and fixing the end of the core.

[0009] Preferably, the edges and corners of the molding sleeve are rounded.

[0010] Also disclosed is a method for forming a part by internally controlled hot isostatic pressing, which uses the above-mentioned internally controlled hot isostatic pressing part forming die, comprising the following steps:

[0011] S1, filling powder particles into the forming cavity through the powder filling port;

[0012] S2, evacuating the interior of the molding cavity through the powder filling port, and then sealing the powder filling port;

[0013] S3, placing the internally controlled hot isostatic pressing part forming die into a hot isostatic pressing furnace for hot isostatic pressing;

[0014] S4. The green compact without interconnected pores obtained by hot isostatic pressing is removed by machining or acid leaching to obtain a part by removing the circular base block, the forming sleeve, the control mold, and the core;

[0015] S5. Trimming and surface treating the parts to obtain final formed parts.

[0016] Preferably, step S4' is included between step S4 and step S5: placing the part obtained in step S4 into the hot isostatic pressing furnace for hot isostatic pressing again, and the temperature and pressure of the hot isostatic pressing are both increased.

[0017] Preferably, the part obtained in step S5 is subjected to stress relief annealing.

[0018] Preferably, in step S2, the powder particles are filled by vibrating the powder, and the density of the initial powder filling needs to be ≥65%.

[0019] Preferably, step S0 is included between step S1: performing structural analysis on the part, determining the powder dosage, the thickness of the lower powder molding layer and the thickness of the upper powder molding layer according to the powder shrinkage rate, determining the relative positions of the circular base block and the control mold, and obtaining models of the circular base block, molding sleeve, control mold and core, and then importing the model into finite element software for simulation, and further optimizing the structure of the circular base block, molding sleeve, control mold and core according to the numerical simulation results until the simulation results of the part geometric accuracy that meets the requirements are obtained, and then preparing the circular base block, molding sleeve, control mold and core by mechanical processing according to the simulation results, and performing surface polishing and cleaning on the circular base block and molding sleeve to remove oil and impurities on the surface of the material, and then assembling the molding sleeve, circular base block, control mold and core.

[0020] Compared with the prior art, the present invention has achieved the following technical effects:

[0021] 1. The forming mold of the present invention is designed with structural compensation, which divides the forming cavity between the forming sleeve, the core and the circular base block into two upper and lower powder forming layers. The upper layer is the main forming layer and the lower layer is the compensation layer. When the hot isostatic pressing process is carried out, the upper and lower powder layers can shrink synchronously, so that the forces on the upper and lower sides of the control mold are balanced, preventing one side from shrinking too much and causing warping.

[0022] 2. The forming mold of the present invention optimizes the core structure by replacing the cylindrical core with a tubular core, which can not only reduce material consumption but also reduce the warping deformation of the part. When using a tubular core, the high-pressure gas in the hot isostatic pressing furnace can enter the middle of the tubular core. This force acts on the inner wall of the tubular core, causing it to expand. For the powder jacket as a whole, this force is exactly opposite to the warping deformation, thus reducing the warping deformation.

[0023] 3. The structure of the forming sleeve in the forming mold of the present invention adopts a rounded and smooth transition to solve the problem of the "stress shielding" effect caused by the right-angle transition that the pressure cannot be well transmitted to the internal powder. It can ensure that the powder is subjected to sufficient pressure and the force is balanced, thereby ensuring the density of the parts.

[0024] 4. In the forming method of the present invention, the parts are subjected to two hot isostatic pressings, and the pressure and temperature of the second hot isostatic pressing are increased, which can effectively prevent the warping deformation caused by uneven powder shrinkage and fully ensure the density of the parts.

[0025] 5. In the forming method of the present invention, by annealing the formed parts, the internal stress can be effectively eliminated, thereby reducing the warping deformation of the parts after hot isostatic pressing, so that the parts meet the shape and position tolerance requirements.

[0026] 6. In the forming method of the present invention, when making the forming mold, the warping and deformation problems of the parts are effectively reduced by combining multiple methods such as powder solid structure compensation, optimized design of the sheath mold, hot isostatic pressing process optimization, and numerical simulation assisted verification, thereby ensuring the forming accuracy of the parts, shortening the subsequent processing cycle for removing the sheath, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a structural schematic diagram of the internal controlled hot isostatic pressing part forming die;

[0029] Figure 2 Schematic diagram of the three-dimensional structure of the formed part

[0030] Figure 3 Schematic diagram of the perspective structure of the formed part

[0031] Figure 4 It is the front view of the formed part;

[0032] Figure 5 for Figure 4 Cross-sectional view at AA in the middle;

[0033] Figure 6 It is a structural schematic diagram of an existing forming die;

[0034] Figure 7A schematic diagram of the structure of a formed part that is warped when produced using an existing forming die;

[0035] Figure 8 Flowchart of the internal controlled hot isostatic pressing part forming method.

[0036] Explanation of the accompanying reference numerals: 1. circular base block; 2. molding sleeve; 3. control mold; 4. core; 5. upper powder molding layer; 6. lower powder molding layer; 7. molded part; 8. connecting ribs. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiment is only one embodiment of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention. Example

[0038] This embodiment provides an internally controlled hot isostatic pressing part forming die, such as Figures 1 to 8As shown, it includes a circular base block 1, a molding sleeve 2, a control mold 3 and a core 4, wherein the circular base block 1 is located at the bottom as a part of the sleeve, and plays a role of bearing and sealing. The molding sleeve 2 is covered on the circular base block 1, and the molding sleeve 2 and the circular base block 1 are sealed and can be sealed by welding. Of course, if there are other methods, other methods can also be used. A reserved hole is provided in the center of the circular base block 1, and the bottom end of the core 4 is vertically installed in the reserved hole. The top end of the core 4 is used to support the molding sleeve 2 and is fixedly connected to the molding sleeve 2. Similarly, the core 4 and the reserved hole and the molding sleeve 2 can also be welded. Similarly, if there are other methods, other methods can also be used. The control mold 3 is fixedly connected to the core 4, and can be welded or interference fit, which is effectively welding. The control mold 3 divides the molding cavity into an upper powder molding layer 5 and a lower powder molding layer 6, which are distributed vertically. The control mold 3 is set according to the shape of the part to be controlled. However, a connecting gap is reserved on the control mold 3. The connecting gap allows the upper powder molding layer 5 and the lower powder molding layer 6 to communicate with each other. After filling with powder, the powder in the upper powder molding layer 5 and the powder in the lower powder molding layer 6 can contact each other through the connecting gap, so that the powder can form a connecting rib 8 in the connecting gap during hot isostatic pressing to connect the molded part in the upper powder molding layer 5 and the molded part in the lower powder molding layer 6. The molding sleeve 2 is provided with a powder filling port to be sealed. The powder filling port is connected to the upper powder molding layer 5. Powder can be filled into the upper powder molding layer 5 through the powder filling port. The powder can penetrate into the lower powder molding layer 6 through the connecting gap. Vibration can be used during filling to ensure that the powder can effectively fill the lower powder molding layer 6 and avoid incomplete filling due to obstruction of the control mold 3. On the other hand, it can ensure that the powder is dense. In addition, the molding cavity can be vacuumed through the powder filling port and sealed after vacuuming to ensure that the molding cavity is always in a sealed state during the hot isostatic pressing process. The sealing can be performed by a sealing member or by welding. In order to ensure the integrity of the molding sleeve 2, welding is preferred.

[0039] Working principle:

[0040] First, the powder is filled into the molding cavity through the powder filling port, and the vibration powder filling method is adopted during filling to ensure that the upper powder molding layer 5 and the lower powder molding layer 6 are full of powder, and the density reaches the preset requirements; then, the molding cavity is evacuated, and after the vacuum degree reaches the standard, the powder filling port is sealed; then, the above-mentioned mold and the powder are placed together in a hot isostatic pressing furnace for hot isostatic pressing. The hot isostatic pressing temperature is determined according to the melting point of the powder material. As an optimal method, the hot isostatic pressing temperature is 0.5~0.6 of the absolute temperature of the melting point of the powder material, the holding time is 2~3h, and the pressure is 80~120MPa. After hot isostatic pressing, the powder will be connected to the circular base block, molding sleeve, control mold and core to form an integral compact; then, the obtained compact is removed from the circular base block 1, molding sleeve 2, control mold 3 and core 4 by machining or acid leaching; finally, the above-mentioned parts are properly trimmed and surface treated to obtain the final formed part 7. Preferably, after the first hot isostatic pressing (HIP) of the part, a second HIP can be performed to increase the density of the part. This time, the temperature and pressure in the HIP furnace are both increased, preferably to 0.6-0.75°C (1.8-2.6°F) above the absolute melting point of the powder material, with a holding time of 2-3 hours and a pressure of 100-200 MPa. Furthermore, to eliminate stress, the formed part 7 can be subjected to stress relief annealing after the second HIP to eliminate residual stress within the part.

[0041] Furthermore, in this embodiment, if Figures 1 to 8 As shown, the thickness of the lower powder molding layer 6 must satisfy h ≥ 1 / 2H, where h is the thickness of the lower powder molding layer 6 and H is the thickness of the upper powder molding layer 5. This thickness effectively balances the large deformation caused by powder shrinkage within the upper powder molding layer 5, ensuring balanced forces on the upper and lower sides of the control mold 3 and preventing warping caused by excessive shrinkage on one side. The specific h ≥ 1 / 2H is determined based on experience and numerical simulation results obtained by importing the mold model into finite element software.

[0042] In this embodiment, Figures 1 to 8 As shown, the core 4 is a tubular core. The purpose of setting the tubular core is to reduce warping deformation. During the molding process, the high-pressure gas in the hot isostatic pressing furnace can enter the middle of the tubular core and act on the inner wall of the tubular core, weakening the shielding effect of the force and balancing the pressure, thereby reducing warping deformation. However, if the wall thickness of the tubular core is too thick, it will not have a weakening effect. If the thickness is too small, it will be damaged and leak during the deformation process, affecting the molding. The wall thickness range of the tubular core is determined to be 1 / 10L≤t≤3 / 10L, where t is the wall thickness of the tubular core and L is the radius of the circular base block 1 minus the radius of the tubular core. Of course, the above is only a preferred method, and does not mean that only tubular cores can be used. In practice, solid cylindrical cores can still be used.

[0043] In this embodiment, Figures 1 to 8 As shown, the top end face of the core 4 and the top inner wall of the molding sleeve 2 are welded, and a connecting hole is provided in the middle of the molding sleeve 2. The connecting hole has the same inner diameter as the core 4 and is coaxially connected. This method can ensure that high-pressure gas can enter the interior of the tubular core from the connecting hole and the reserved hole at the same time, ensuring that the inner wall of the core 4 is evenly stressed.

[0044] Furthermore, in order to optimize the force of the forming sleeve 2, in this embodiment, as Figures 1 to 8 As shown, the diameter of the connecting hole is increased to match the outer diameter of the core 4, so that the top of the core 4 can be inserted into the connecting hole and fixed thereto, and the fixing method can be welding. This method can prevent the core 4 from affecting the deformation of the molding sleeve 2 at its top.

[0045] In this embodiment, Figures 1 to 8 As shown, the wall thickness of the molding sleeve 2 is 2~5mm. This thickness range is more suitable for the size of turbine disk parts. Of course, this range is only a reference value. The specific wall thickness can be designed according to the actual part structure and shape, especially for non-turbine disk parts.

[0046] Furthermore, in this embodiment, if Figures 1 to 8 As shown, the corners of the forming sleeve 2 adopt rounded transition to avoid the problem of difficult deformation caused by structural mutation. The existing sleeve structure usually adopts right-angle transition and is connected together by welding. In the study, it was found that the structural mutation caused by the right-angle transition and the weld position will produce a "stress shielding" effect. This part makes it impossible for the pressure in the hot isostatic pressing furnace to be well transmitted to the internal powder, resulting in small and uneven force on the powder, small powder shrinkage and low density. The rounded transition will reduce the imbalance of force on the powder and reduce the degree of warping deformation. In addition, the length and number of single welds should be minimized during welding. Example

[0047] This embodiment provides a method for forming a part by internally controlled hot isostatic pressing, which uses the internally controlled hot isostatic pressing part forming die in Example 1. Figures 1 to 8 As shown, the following steps are included:

[0048] S1. Fill powder particles into the forming die cavity through the powder filling port, ensuring that there are no dead corners in the upper powder forming layer 5 and the lower powder forming layer 6, and the density meets the preset requirements;

[0049] S2. Evacuate the interior of the molding cavity through the powder filling port, and then seal the powder filling port. A seal or welding seal may be used, preferably a welding seal.

[0050] S3. Place the internal controlled hot isostatic pressing part forming die into a hot isostatic pressing furnace for hot isostatic pressing. The hot isostatic pressing temperature is determined according to the melting point of the powder material. Preferably, the hot isostatic pressing temperature is 0.5-0.6 of the absolute melting point of the powder material, the holding time is 2-3 hours, and the pressure is 80-120 MPa.

[0051] S4. The green compact without interconnected pores obtained by hot isostatic pressing is machined or pickled to remove the circular base block 1, the forming sleeve 2, the control mold 3, and the core 4 to obtain a part with internal control.

[0052] S5. The internally shaped part is properly trimmed and surface treated to obtain the final formed part 7.

[0053] Furthermore, in this embodiment, if Figures 1 to 8 As shown, between step S4 and step S5, step S4' is included: placing the formed part 7 obtained in step S4 into a hot isostatic pressing furnace for hot isostatic pressing again to improve the density of the part, the hot isostatic pressing temperature is 0.6-0.75 of the absolute temperature of the melting point of the powder material, the holding time is 2-3 hours, and the pressure is 100-200 MPa;

[0054] In this embodiment, Figures 1 to 8 As shown, the part obtained in step S4 ′ is subjected to stress relief annealing to eliminate the residual stress inside the formed part 7 .

[0055] In this embodiment, Figures 1 to 8 As shown, in step S2, powder particles are filled by vibrating powder filling, and the density of the initial powder filling needs to be ≥65%.

[0056] Furthermore, in this embodiment, if Figures 1 to 8As shown, step S1 includes step S0: performing structural analysis on the part, determining the powder dosage, the thickness of the lower powder molding layer 6 and the thickness of the upper powder molding layer 5 according to the powder shrinkage rate, determining the relative positions of the circular base block 1 and the control mold 3, and obtaining the models of the circular base block 1, the molding sleeve 2, the control mold 3 and the core 4, and then importing the model into the finite element software for simulation, and further optimizing the structures of the circular base block 1, the molding sleeve 2, the control mold 3 and the core 4 according to the numerical simulation results until the simulation results of the part geometric accuracy that meet the requirements are obtained, and then preparing the circular base block 1, the molding sleeve 2, the control mold 3 and the core 4 by mechanical processing according to the simulation results, and performing surface polishing and cleaning on the molding sleeve 2 and the circular base block 1 to remove oil and impurities on the surface of the material, and alcohol and acetone can be used as cleaning agents for cleaning, and then the circular base block 1, the molding sleeve 2, the control mold 3 and the core 4 are assembled. Welding can be used for assembly, and spot welding can be used to fix positions where there is no airtightness requirement to ensure that they do not move relative to each other, while minimizing the length and number of single welds.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An internally controlled hot isostatic pressing part forming die, characterized in that: The invention comprises a circular base block and a molding sleeve which is covered on the circular base block, the molding sleeve and the circular base block are sealed and connected, a reserved hole is provided in the center of the circular base block, a core for supporting and fixing the molding sleeve is installed in the reserved hole, a molding cavity is provided between the core, the circular base block and the molding sleeve, the molding cavity comprises an upper powder molding layer and a lower powder molding layer which are distributed up and down, a control mold fixed on the core is provided between the upper powder molding layer and the lower powder molding layer, and the control mold A connection gap is reserved on the upper portion to connect the upper powder molding layer and the lower powder molding layer; a powder filling port to be sealed is provided on the molding sleeve, and the powder filling port is connected to the upper powder molding layer; the thickness of the lower powder molding layer must satisfy h≥1 / 2H, where h is the thickness of the lower powder molding layer and H is the thickness of the upper powder molding layer; the core is a tubular core, and the wall thickness of the tubular core must satisfy 1 / 10L≤t≤3 / 10L, where t is the wall thickness of the tubular core and L is the radius of the circular base block minus the radius of the tubular core.

2. The internally controlled hot isostatic pressing part forming die according to claim 1, characterized in that: A communicating hole is provided in the middle of the molding sleeve for inserting and fixing the end of the core.

3. The internally controlled hot isostatic pressing part forming die according to claim 2, characterized in that: The edges and corners of the molding sleeve are rounded.

4. A method for forming a part by internally controlled hot isostatic pressing, using the internally controlled hot isostatic pressing part forming die according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, filling powder particles into the forming cavity through the powder filling port; S2, evacuating the interior of the molding cavity through the powder filling port, and then sealing the powder filling port; S3, placing the internally controlled hot isostatic pressing part forming die into a hot isostatic pressing furnace for hot isostatic pressing; S4. The green compact without interconnected pores obtained by hot isostatic pressing is removed by machining or acid leaching to obtain a part by removing the circular base block, the forming sleeve, the control mold, and the core; S5. Trimming and surface treating the parts to obtain final formed parts.

5. The internal controlled hot isostatic pressing part forming method according to claim 4, characterized in that: Between step S4 and step S5 there is step S4': placing the part obtained in step S4 into the hot isostatic pressing furnace for hot isostatic pressing again, with the temperature and pressure of the hot isostatic pressing being increased.

6. The method for forming a part by internally controlled hot isostatic pressing according to claim 5, wherein: The component obtained in step S4' is subjected to stress relief annealing.

7. The internal controlled hot isostatic pressing part forming method according to claim 4, characterized in that: In step S2, powder particles are filled by vibrating powder filling, and the density of the initial powder filling needs to be ≥65%.

8. The method for forming a part by internally controlled hot isostatic pressing according to claim 4, wherein: Step S1 includes step S0: performing structural analysis on the part, determining the powder dosage, the thickness of the lower powder molding layer and the thickness of the upper powder molding layer according to the powder shrinkage rate, determining the relative positions of the circular base block and the control mold, and obtaining models of the circular base block, molding sleeve, control mold and core, and then importing the model into finite element software for simulation, and further optimizing the circular base block, molding sleeve, control mold and core structure according to the numerical simulation results until the part geometric accuracy simulation results that meet the requirements are obtained, and then preparing the circular base block, molding sleeve, control mold and core by mechanical processing according to the simulation results, polishing and cleaning the circular base block and molding sleeve to remove oil and impurities on the surface of the material, and then assembling the circular base block, molding sleeve, control mold and core.

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