A method of co-sintering of metal injection molded fitments

Abstract

This invention discloses a collaborative sintering method for metal injection molded mating parts, comprising the following steps: Step 1: Degreasing, using a solvent to decompose the binder in the metal powder. This invention upgrades the atmosphere conditioning gas supplied to the inside of the sintering chamber from "static laminar flow" to "three-dimensional dynamic turbulent flow" by setting up a gas delivery component, a forward and reverse drive component, and a longitudinal lateral movement component. This reduces the fluctuation range of oxygen content within the sintering chamber; the lateral and longitudinal temperature differences are simultaneously reduced, improving the roundness, coaxiality, and dimensional consistency of the mating parts, reducing post-processing allowances, and increasing material utilization; eliminating local overblowing and dead zones, reducing the incidence of defects such as mold sticking, corner collapse, and carbon black, and increasing the first-pass yield; furthermore, the setting of the molding separator and sintering sand allows two parts to be sintered simultaneously in the sintering mold. The fact that the two parts are in the same sintering environment reduces sintering errors and decreases the part shaping process required for parts with large sintering errors.

Description

Technical Field

[0001] This invention relates to the field of sintering technology for metal injection molded mating parts, and in particular to a method for co-sintering metal injection molded mating parts. Background Technology

[0002] Metal injection molding (MIM) is an advanced technology that manufactures metal parts by mixing metal powder and polymer binders into an injectable "powder mixture." It combines the efficiency of plastic injection molding with the advantages of powder metallurgy, making it suitable for manufacturing complex-shaped, high-precision metal parts. It is widely used in the automotive, electronics, medical, aerospace, tooling, and consumer goods industries. MIM parts are workpieces formed through metal injection molding. During processing, MIM parts undergo sintering, which diffuses and fuses the raw materials to form a strong metal structure, significantly increasing the workpiece's density.

[0003] Currently, in the sintering stage of metal injection molded (MIM) parts, the uniformity and controllability of the furnace atmosphere directly determine the removal efficiency of residual carbon after degreasing, the degree of grain boundary oxidation, and the final density. Traditional MIM part sintering equipment uses a side-wall fixed gas inlet method to deliver gas into the equipment. This method has the following drawbacks:

[0004] The airflow is distributed in layers, which can easily form a low-velocity "dead zone" deep in the cavity, resulting in excessively high local oxygen partial pressure; constant unidirectional purging causes the temperature-atmosphere coupling field to be distributed in a gradient, and the lateral temperature difference induces non-uniform shrinkage, resulting in out-of-tolerance roundness and coaxiality of mating parts; the consumption of atmosphere conditioning gases (hydrogen, nitrogen, argon, etc.) is large, the replacement cycle is long, the production cost is high, and there is a risk of combustion and explosion. Summary of the Invention

[0005] The purpose of this application is to provide a method for the collaborative sintering of metal injection molded mating parts, thereby solving the problems mentioned in the background art.

[0006] Firstly, the collaborative sintering method for metal injection molded mating parts provided in this application adopts the following technical solution, including the following steps:

[0007] Step 1: Degreasing, using solvents to decompose the binder in the metal powder;

[0008] Step 2: Pre-sintering, carried out at a low temperature (close to or below the melting point of the metal powder) to ensure that the metal powder particles can begin to fuse but are not yet fully densified;

[0009] Step 3: Sintering. Sintering is a key step in completely fusing and densifying metal powder. During sintering, metal particles diffuse and fuse to form a strong metal structure, and the density of the part increases significantly.

[0010] Step 4: High-pressure sintering. High-pressure sintering is a process that applies isostatic pressure to further improve the density of the parts and reduce porosity and defects.

[0011] Step 5: Surface treatment, improving surface smoothness through mechanical polishing;

[0012] Step Six: Quality Inspection and Characterization. The density of the parts is tested by water displacement and gas displacement methods. The hardness of the parts is tested by Rockwell hardness and Vickers hardness. The microstructure of the metal is observed by microscopy to determine the sintering quality and particle size distribution. The tensile strength, ductility and toughness of the parts are tested by tensile test and impact test.

[0013] The processing equipment described in step three includes a sintering box and a placement platform located inside the sintering box. A sintering mold is placed on the placement platform. A forming partition plate is provided inside the sintering mold. Sintering sand is attached to the forming partition plate. A limiting groove is formed on the inner wall of the sintering mold. The two ends of the forming partition plate with sintering sand attached are inserted into the limiting groove. A gas regulating component is provided on one side of the sintering box. The gas regulating component includes a gas conveying component, a forward and reverse rotation drive component, and a longitudinal lateral movement component. The gas conveying component is located on one side of the sintering box. The forward and reverse rotation drive component and the longitudinal lateral movement component are located on the gas conveying component.

[0014] Preferably, the gas delivery assembly includes a support platform, a fixed plate, a fan, a flexible air delivery hose, a delivery pipe, an outlet pipe, and a heat insulation pipe, with the support platform located on one side of the sintering box.

[0015] Preferably, the fixing plate and the fan are arranged on both sides of the upper end face of the support platform, one end of the air supply hose is connected to the air outlet of the fan, the heat insulation pipe passes through the fixing plate, and the other end of the air supply hose is connected to one end of the heat insulation pipe.

[0016] Preferably, one end of the conveying pipe is connected to the heat insulation pipe, the end of the conveying pipe away from the heat insulation pipe extends to the inside of the sintering box, the gas outlet pipe is located inside the sintering box, the gas outlet pipe is provided with multiple sets of gas outlet holes, each set of gas outlet holes has multiple holes, one end of the gas outlet pipe is connected to the conveying pipe extending to the inside of the sintering box, and the gas outlet pipe is located above the placement platform.

[0017] In the above technical solution, the exhaust pipe is located directly above the placement platform, and the downward spray forms an air curtain that immediately isolates the degreased volatiles from the air, inhibits carbon oxidation, and reduces the thickness of the decarburized layer; the heat insulation pipe blocks the heat conduction between the low-temperature zone at the fan end and the high-temperature zone at the sintering box, preventing the fan impeller from deforming due to heat and extending its service life; the air delivery hose absorbs the axial displacement of the heat insulation pipe, ensuring zero leakage throughout the process, improving hydrogen utilization, and reducing the risk of combustion and explosion.

[0018] Secondly, the collaborative sintering method for metal injection molded mating parts provided in this application adopts the following technical solution: the forward and reverse rotation drive assembly includes a drive motor, a transmission gear, a gear ring, a half gear, a transmission groove, a transmission protrusion, a transmission shaft, and a fixed gear, and the drive motor is mounted on a fixed plate through a support frame.

[0019] Preferably, there are two transmission gears, which are rotatably connected to one side wall of the fixed plate and mesh with each other. The toothed ring is rotatably connected to the other side wall of the fixed plate and is sleeved on the heat insulation pipe that passes through the fixed plate.

[0020] Preferably, there are two half gears, which are arranged in a circular array with the toothed ring as the center, and the two half gears are respectively connected to the two transmission gears, and both half gears are tangent to the toothed ring.

[0021] Preferably, the transmission groove is formed on the outer wall surface of the heat insulation pipe, and multiple transmission grooves are equally spaced. The transmission protrusion is set on the inner wall surface of the toothed ring, and multiple transmission protrusions are provided. The multiple transmission protrusions are slidably connected in multiple transmission grooves respectively.

[0022] Preferably, one end of the drive shaft is connected to the impeller of the fan, and two fixed gears are provided. The two fixed gears are rotatably connected to the two side walls of the fixed plate and are connected to each other. One fixed gear meshes with a drive gear, and the end of the drive shaft away from the fan is connected to the other fixed gear.

[0023] The above technical solution uses periodic forward and reverse rotation to allow the vent holes of the exhaust pipe to sweep across the cavity in a "sweeping" manner. The transverse airflow velocity field is periodically and symmetrically distributed, the transverse temperature difference is homogenized, the circumferential shrinkage of the mating parts is consistent, and the roundness error is significantly reduced. Alternating reverse blowing breaks the boundary layer, allowing volatiles to exchange rapidly with fresh gas. The degreasing residual carbon can be fully reduced in the low-temperature pre-sintering stage, reducing the deposition of "carbon black" during subsequent high-temperature sintering and improving the cycle life of the sintering sand. The half gear and gear ring are purely mechanically driven, requiring no additional servo controller. The structure is compact, the failure rate is low, and it can work for a long time in a reducing atmosphere.

[0024] Thirdly, the collaborative sintering method for metal injection molded mating parts provided in this application adopts the following technical solution: the longitudinal transverse moving assembly includes a fixed cylinder fixedly mounted on a fixed plate and a protrusion mounted on a heat insulation tube. The heat insulation tube passes through the fixed cylinder, and a spiral groove is opened on the inner wall of the fixed cylinder. The protrusion on the heat insulation tube is slidably connected in the spiral groove.

[0025] The above technical solution directly converts rotational power into axial reciprocating motion through the spiral groove-protrusion structure, eliminating the need for an independent linear drive source and simplifying the system. The longitudinal back-and-forth movement of the exhaust pipe creates multiple "push-pull" effects in the cavity depth direction, smoothing out the longitudinal oxygen partial pressure gradient and reducing the density difference between the upper and lower sections of the part. The three-dimensional spiral airflow generates flexible disturbances on the sintering sand, preventing sand particles from being continuously blown away at fixed points. The forming partition plate is always uniformly wrapped, ensuring the parts have intact edges and corners and eliminating surface "sand adhesion" defects. The reciprocating movement expands the effective purging volume, shortens the furnace atmosphere replacement time, reduces the consumption of atmosphere conditioning gases (hydrogen, nitrogen, argon, etc.), and accelerates the production cycle.

[0026] In summary, this application includes the following beneficial technical effects:

[0027] 1. The exhaust pipe is located directly above the placement platform. The downward spray of air forms an air curtain that immediately isolates the degreased volatiles from the air, inhibiting carbon oxidation and reducing the thickness of the decarburized layer. The heat insulation pipe blocks heat conduction between the low-temperature zone at the fan end and the high-temperature zone in the sintering box, preventing the fan impeller from deforming due to heat and extending its service life. The air delivery hose absorbs the axial displacement of the heat insulation pipe, ensuring zero leakage throughout the process, improving hydrogen utilization, and reducing the risk of combustion and explosion.

[0028] 2. Periodic forward and reverse rotation causes the vent holes of the exhaust pipe to sweep across the cavity in a "sweeping" manner, resulting in a periodic and symmetrical distribution of the transverse airflow velocity field. This homogenizes the transverse temperature difference, ensures consistent circumferential shrinkage of mating parts, and significantly reduces roundness error. Alternating reverse blowing breaks the boundary layer, allowing volatiles to exchange rapidly with fresh gas. Degreasing residual carbon can be fully reduced during the low-temperature pre-sintering stage, reducing "carbon black" deposition during subsequent high-temperature sintering and improving the cycle life of sintering sand. The half-gear and gear ring are purely mechanically driven, requiring no additional servo controller. The structure is compact, has a low failure rate, and can operate for extended periods in a reducing atmosphere.

[0029] 3. The spiral groove-protrusion structure directly converts rotational power into axial reciprocating motion, eliminating the need for an independent linear drive source and simplifying the system. The exhaust pipe moves back and forth longitudinally, creating multiple "push-pull" effects in the cavity depth direction, smoothing out the longitudinal oxygen partial pressure gradient and reducing the density difference between the upper and lower sections of the part. The three-dimensional spiral airflow generates flexible disturbances on the sintering sand, preventing sand particles from being continuously blown away at fixed points. The forming partition plate is always uniformly wrapped, ensuring the parts have intact edges and corners and eliminating surface "sand adhesion" defects. The reciprocating movement expands the effective purging volume, shortens the furnace atmosphere replacement time, reduces the consumption of atmosphere conditioning gases (hydrogen, nitrogen, argon, etc.), and speeds up the production cycle. Attached Figure Description

[0030] Figure 1 This is a first-view schematic diagram of the overall structure of an embodiment of this application.

[0031] Figure 2 This is a second-view schematic diagram of the overall structure of an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the overall internal structure of the sintering box according to an embodiment of this application;

[0033] Figure 4 This is a first-view perspective perspective of a gas regulation component according to an embodiment of this application;

[0034] Figure 5 This is a second perspective view of a gas regulation component according to an embodiment of this application;

[0035] Figure 6 This is an exploded view of the gas regulation component according to an embodiment of this application;

[0036] Figure 7 This is a cross-sectional view of the fixed cylinder according to an embodiment of this application;

[0037] Figure 8 This is an exploded view of the sintering mold and forming partition plate according to an embodiment of this application;

[0038] Figure 9 This is a schematic diagram illustrating the process principle of an embodiment of this application.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Sintering box; 2. Placement platform; 3. Sintering mold; 4. Gas conditioning assembly; 41. Gas conveying assembly; 411. Support platform; 412. Fixing plate; 413. Fan; 414. Air supply hose; 415. Conveying pipe; 416. Gas outlet pipe; 417. Heat insulation pipe; 42. Forward and reverse drive assembly; 421. Drive motor; 422. Transmission gear; 423. Gear ring; 424. Half gear; 425. Transmission groove; 426. Transmission protrusion; 427. Transmission shaft; 428. Fixed gear; 43. Longitudinal and transverse movement assembly; 431. Fixing cylinder; 432. Protrusion; 433. Spiral groove; 5. Limiting groove; 6. Sintering sand. Detailed Implementation

[0041] The following is in conjunction with the appendix Figure 1 - Appendix Figure 9 This application will be described in further detail below.

[0042] Example 1: A method for co-sintering of metal injection-molded mating parts, comprising the following steps:

[0043] Step 1: Degreasing, using solvents to decompose the binder in the metal powder;

[0044] Step 2: Pre-sintering, carried out at a low temperature (close to or below the melting point of the metal powder) to ensure that the metal powder particles can begin to fuse but are not yet fully densified;

[0045] Step 3: Sintering. Sintering is a key step in completely fusing and densifying metal powder. During sintering, metal particles diffuse and fuse to form a strong metal structure, and the density of the part increases significantly.

[0046] Step 4: High-pressure sintering. High-pressure sintering is a process that applies isostatic pressure to further improve the density of the parts and reduce porosity and defects.

[0047] Step 5: Surface treatment, improving surface smoothness through mechanical polishing;

[0048] Step Six: Quality Inspection and Characterization. The density of the parts is tested by water displacement and gas displacement methods. The hardness of the parts is tested by Rockwell hardness and Vickers hardness. The microstructure of the metal is observed by microscopy to determine the sintering quality and particle size distribution. The tensile strength, ductility and toughness of the parts are tested by tensile test and impact test.

[0049] The processing equipment described in step three includes a sintering box 1 and a placement platform 2 located inside the sintering box 1. A sintering mold 3 is placed on the placement platform 2. A forming partition plate is provided inside the sintering mold 3. Sintering sand 6 is attached to the forming partition plate. A limiting groove 5 is opened on the inner wall of the sintering mold 3. The two ends of the forming partition plate with sintering sand 6 are inserted into the limiting groove 5. A gas regulating component 4 is provided on one side of the sintering box 1. The gas regulating component 4 includes a gas conveying component 41, a forward and reverse drive component 42, and a longitudinal lateral movement component 43. The gas conveying component 41 is located on one side of the sintering box 1. The forward and reverse drive component 42 and the longitudinal lateral movement component 43 are located on the gas conveying component 41.

[0050] The setting of the forming partition plate and sintering sand 6 allows two parts to be sintered simultaneously in the sintering mold 3. The fact that the two parts are in the same sintering environment can reduce the sintering error of the parts, reduce the part shaping process required for parts with large sintering errors, and improve the production efficiency of parts.

[0051] It should be noted that multiple forming partition plates with sintering sand 6 attached inside the sintering mold 3 can be set, and multiple sets of limiting grooves 5 can be set, so that multiple parts can be sintered on the inside of the sintering mold 3 at the same time.

[0052] The gas delivery assembly 41 includes a support platform 411, a fixing plate 412, a fan 413, an air delivery hose 414, a delivery pipe 415, an outlet pipe 416, and a heat insulation pipe 417. The support platform 411 is located on one side of the sintering box 1.

[0053] The fixing plate 412 and the fan 413 are arranged on both sides of the upper end face of the support platform 411. One end of the air supply hose 414 is connected to the air outlet of the fan 413. The heat insulation pipe 417 passes through the fixing plate 412, and the other end of the air supply hose 414 is connected to one end of the heat insulation pipe 417.

[0054] One end of the conveying pipe 415 is connected to the heat insulation pipe 417. The end of the conveying pipe 415 away from the heat insulation pipe 417 extends to the inside of the sintering box 1. The vent pipe 416 is located inside the sintering box 1. The vent pipe 416 is provided with multiple sets of vent holes, and each set of vent holes has multiple vent holes. One end of the vent pipe 416 is connected to the conveying pipe 415 extending to the inside of the sintering box 1. The vent pipe 416 is located above the placement platform 2.

[0055] In use: After the gas delivery assembly 41 (support platform 411, fixing plate 412, fan 413, air delivery hose 414, delivery pipe 415, outlet pipe 416, heat insulation pipe 417) is started, the fan 413 sends the gas from the external storage tank containing protective gas (hydrogen, nitrogen or a mixture thereof) through the air delivery hose 414, heat insulation pipe 417, and delivery pipe 415 into the outlet pipe 416. The outlet pipe 416 is suspended directly above the placement platform 2, and its multiple circumferentially distributed outlet holes vertically spray the gas and form an initial protective layer between the sintering mold 3 and the forming partition plate, which quickly reduces the oxygen partial pressure.

[0056] The exhaust pipe 416 is located directly above the placement platform 2. The downward spray of air forms an air curtain that immediately isolates the degreased volatiles from the air, inhibits carbon oxidation, and reduces the thickness of the decarburized layer. The heat insulation pipe 417 blocks the heat conduction between the low-temperature zone of the fan 413 and the high-temperature zone of the sintering box 1, preventing the impeller of the fan 413 from deforming due to heat and extending its service life. The air delivery hose 414 absorbs the axial displacement of the heat insulation pipe 417, ensuring zero leakage throughout the process, improving hydrogen utilization, and reducing the risk of combustion and explosion.

[0057] Example 2: A method for co-sintering of metal injection molded mating parts, wherein the forward and reverse drive assembly 42 includes a drive motor 421, a transmission gear 422, a gear ring 423, a half gear 424, a transmission groove 425, a transmission protrusion 426, a transmission shaft 427 and a fixed gear 428, and the drive motor 421 is mounted on a fixed plate 412 by a support frame.

[0058] It should be noted that a controller is installed on the support platform 411, which is used to control the operating status of the drive motor 421.

[0059] Two transmission gears 422 are provided, and the two transmission gears 422 are rotatably connected to one side wall of the fixed plate 412 and mesh with each other. The toothed ring 423 is rotatably connected to the other side wall of the fixed plate 412 and is sleeved on the heat insulation pipe 417 that passes through the fixed plate 412.

[0060] Two half-gears 424 are provided, and the two half-gears 424 are arranged in a circular array with the toothed ring 423 as the center. The two half-gears 424 are respectively connected to the two transmission gears 422, and both half-gears 424 are tangent to the toothed ring 423.

[0061] The transmission groove 425 is formed on the outer wall of the heat insulation tube 417, and multiple transmission grooves 425 are equally spaced. The transmission protrusion 426 is set on the inner wall of the toothed ring 423, and multiple transmission protrusions 426 are provided. The multiple transmission protrusions 426 are slidably connected in the multiple transmission grooves 425 respectively.

[0062] One end of the drive shaft 427 is connected to the impeller of the fan 413. Two fixed gears 428 are provided. The two fixed gears 428 are rotatably connected to the two side walls of the fixed plate 412 and are connected to each other. One fixed gear 428 meshes with a drive gear 422. The end of the drive shaft 427 away from the fan 413 is connected to the other fixed gear 428.

[0063] In use: When the forward and reverse drive assembly 42 (drive motor 421, transmission gear 422, gear ring 423, half gear 424, transmission groove 425, transmission protrusion 426, transmission shaft 427, fixed gear 428) is working, the drive motor 421 drives the transmission gear 422 to rotate, the transmission gear 422 drives the meshing transmission gear 422 and fixed gear 428 to rotate, and the fixed gear 428 drives the impeller of the fan 413 through the transmission shaft 427, thus driving the fan 413 to work, thereby driving the fan 413 to expel externally stored protective gas (hydrogen, nitrogen). Gas (or a mixture thereof) is transported from the gas tank to the inside of the sintering box 1. Due to the difference in the number of teeth between the half gear 424 and the transmission gear 422, the gear ring 423 is alternately meshed to achieve periodic forward and reverse rotation. The transmission protrusion 426 on the inner side of the gear ring 423 slides into the transmission groove 425 on the outer wall of the heat insulation tube 417, transmitting the rotational motion to the heat insulation tube 417 without loss. This drives the exhaust pipe 416 at the end to perform an alternating clockwise-counterclockwise compound rotation in the horizontal plane. This motion breaks the traditional fixed airflow path, allowing the jet airflow to cover the entire cavity in an oscillating form, eliminating the static dead zone.

[0064] The periodic forward and reverse rotation causes the vent holes of the vent pipe 416 to sweep across the cavity in a "sweeping" manner, resulting in a periodic and symmetrical distribution of the transverse airflow velocity field. This homogenizes the transverse temperature difference, ensures consistent circumferential contraction of the mating parts, and significantly reduces roundness error. Alternating reverse blowing breaks the boundary layer, allowing volatiles to exchange rapidly with fresh gas. Degreasing residual carbon can be fully reduced during the low-temperature pre-sintering stage, reducing "carbon black" deposition during subsequent high-temperature sintering and improving the cycle life of the sintering sand 6. The half gear 424 and the gear ring 423 are purely mechanically driven, requiring no additional servo controller. They have a compact structure, low failure rate, and can operate for extended periods in a reducing atmosphere.

[0065] Example 3: A method for co-sintering of metal injection molded mating parts, wherein the longitudinal transverse moving assembly 43 includes a fixed cylinder 431 fixedly disposed on a fixed plate 412 and a protrusion 432 disposed on a heat insulation tube 417, the heat insulation tube 417 passing through the fixed cylinder 431, the inner wall of the fixed cylinder 431 being provided with a spiral groove 433, and the protrusion 432 on the heat insulation tube 417 being slidably connected in the spiral groove 433.

[0066] In use: The longitudinal transverse component 43 (fixed cylinder 431, protrusion 432, spiral groove 433) utilizes a "rotation-linear" composite mechanism: when the heat insulation tube 417 is driven to rotate by the toothed ring 423, the protrusion 432 slides in the spiral groove 433 of the fixed cylinder 431, forcing the heat insulation tube 417 to simultaneously undergo axial reciprocating movement. As a result, the exhaust pipe 416 rotates while periodically moving back and forth along the axial direction, and its jet trajectory is upgraded from "planar cycloid" to "three-dimensional spiral", realizing multiple coverage and entrainment of the atmosphere, further enhancing airflow disturbance and heat exchange.

[0067] The spiral groove 433-protrusion 432 structure directly converts rotational power into axial reciprocating motion, eliminating the need for an independent linear drive source and simplifying the system. The exhaust pipe 416 moves back and forth longitudinally, causing the airflow to form multiple "push-pull" effects in the cavity depth direction, smoothing out the longitudinal oxygen partial pressure gradient and reducing the density difference between the upper and lower sections of the part. The three-dimensional spiral airflow generates flexible disturbance on the sintering sand 6, preventing sand particles from being continuously blown away at fixed points, ensuring that the forming partition plate is always uniformly wrapped, the edges and corners of the part are intact, and the surface "sand sticking" defect disappears. The reciprocating movement expands the effective purging volume, shortens the furnace atmosphere replacement time, reduces the consumption of atmosphere conditioning gases (hydrogen, nitrogen, argon, etc.), and speeds up the production cycle.

[0068] Working principle of this invention:

[0069] The preheated raw material is poured into the sintering mold 3. A forming partition plate with sintering sand 6 attached to the sintering mold 3 divides the raw material into two portions. Both portions of raw material are sintered in the same sintering mold 3. During sintering, the gas regulating component 4 is activated. After the gas conveying component 41 is activated, the blower 413 sends the gas from an externally stored protective gas (hydrogen, nitrogen, or a mixture thereof) tank sequentially through the air delivery hose 414, heat insulation pipe 417, and conveying pipe 415 into the outlet pipe 416. The outlet pipe 416 is suspended directly above the placement platform 2, and its circumference... Multiple evenly distributed vents vertically inject gas, forming an initial protective layer between the sintering mold 3 and the forming partition plate, rapidly reducing the oxygen partial pressure. When the forward and reverse drive assembly 42 is working, the drive motor 421 drives the transmission gear 422 to rotate, which in turn drives the meshing transmission gear 422 and the fixed gear 428 to rotate. The fixed gear 428 drives the impeller of the fan 413 through the drive shaft 427, thus driving the fan 413 to work. This drives the fan 413 to expel the externally stored protective gas (hydrogen, nitrogen, or... The gas in the mixed gas tank is transported to the inside of the sintering box 1. Due to the difference in the number of teeth between the half gear 424 and the transmission gear 422, the gear ring 423 is alternately meshed to achieve periodic forward and reverse rotation. The transmission protrusion 426 on the inner side of the gear ring 423 slides into the transmission groove 425 on the outer wall of the heat insulation tube 417, transmitting the rotational motion to the heat insulation tube 417 without loss. This drives the exhaust pipe 416 at the end to perform an alternating clockwise-counterclockwise compound rotation in the horizontal plane. This motion breaks the traditional fixed airflow path, causing the jet airflow to oscillate in an oscillating shape. The entire cavity is covered, eliminating static dead zones; the longitudinal transverse component 43 utilizes a "rotation-linear" composite mechanism: when the heat insulation tube 417 is driven to rotate by the toothed ring 423, the protrusion 432 slides in the spiral groove 433 of the fixed cylinder 431, forcing the heat insulation tube 417 to simultaneously undergo axial reciprocating movement. As a result, the exhaust pipe 416 rotates while periodically moving back and forth along the axial direction, and its spray trajectory is upgraded from "planar cycloid" to "three-dimensional spiral", realizing multiple coverage and entrainment of the atmosphere, further enhancing airflow disturbance and heat exchange.

[0070] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for co-sintering metal injection molded mating parts, characterized in that, Includes the following steps: Step 1: Degreasing, using solvents to decompose the binder in the metal powder; Step 2: Pre-sintering, carried out at a low temperature (close to or below the melting point of the metal powder) to ensure that the metal powder particles can begin to fuse but are not yet fully densified; Step 3: Sintering. Sintering is a key step in completely fusing and densifying metal powder. During sintering, metal particles diffuse and fuse to form a strong metal structure, and the density of the part increases significantly. Step 4: High-pressure sintering. High-pressure sintering is a process that applies isostatic pressure to further improve the density of the parts and reduce porosity and defects. Step 5: Surface treatment, improving surface smoothness through mechanical polishing; Step Six: Quality Inspection and Characterization. The density of the parts is tested by water displacement and gas displacement methods. The hardness of the parts is tested by Rockwell hardness and Vickers hardness. The microstructure of the metal is observed by microscopy to determine the sintering quality and particle size distribution. The tensile strength, ductility and toughness of the parts are tested by tensile test and impact test. The processing equipment described in step three includes a sintering box (1) and a placement platform (2) located inside the sintering box (1). A sintering mold (3) is placed on the placement platform (2). A forming partition plate is provided inside the sintering mold (3). Sintering sand (6) is attached to the forming partition plate. A limiting groove (5) is opened on the inner wall of the sintering mold (3). The two ends of the forming partition plate with sintering sand (6) are inserted into the limiting groove (5). A gas regulating component (4) is provided on one side of the sintering box (1). The gas regulating component (4) includes a gas conveying component (41), a forward and reverse drive component (42), and a longitudinal transverse movement component (43). The gas conveying component (41) is located on one side of the sintering box (1). The forward and reverse drive component (42) and the longitudinal transverse movement component (43) are located on the gas conveying component (41).

2. The method for co-sintering of metal injection-molded mating parts according to claim 1, characterized in that: The gas delivery assembly (41) includes a support platform (411), a fixing plate (412), a fan (413), an air delivery hose (414), a delivery pipe (415), an outlet pipe (416), and a heat insulation pipe (417). The support platform (411) is located on one side of the sintering box (1).

3. The method for co-sintering of metal injection-molded mating parts according to claim 2, characterized in that: The fixing plate (412) and the fan (413) are set on both sides of the upper end face of the support platform (411). One end of the air supply hose (414) is connected to the air outlet of the fan (413). The heat insulation pipe (417) passes through the fixing plate (412). The other end of the air supply hose (414) is connected to one end of the heat insulation pipe (417).

4. The method for co-sintering of metal injection-molded mating parts according to claim 2, characterized in that: The conveying pipe (415) is connected to one end of the heat insulation pipe (417). The end of the conveying pipe (415) away from the heat insulation pipe (417) extends to the inside of the sintering box (1). The gas outlet pipe (416) is located inside the sintering box (1). The gas outlet pipe (416) is provided with multiple sets of gas outlet holes. Each set of gas outlet holes has multiple holes. One end of the gas outlet pipe (416) is connected to the conveying pipe (415) extending to the inside of the sintering box (1). The gas outlet pipe (416) is located above the placement platform (2).

5. The method for co-sintering of metal injection-molded mating parts according to claim 2, characterized in that: The forward and reverse drive assembly (42) includes a drive motor (421), a transmission gear (422), a gear ring (423), a half gear (424), a transmission groove (425), a transmission protrusion (426), a transmission shaft (427), and a fixed gear (428). The drive motor (421) is mounted on a fixed plate (412) via a support frame.

6. The method for co-sintering of metal injection-molded mating parts according to claim 5, characterized in that: Two transmission gears (422) are provided. The two transmission gears (422) are rotatably connected to one side wall of the fixed plate (412) and the two transmission gears (422) mesh with each other. The toothed ring (423) is rotatably connected to the other side wall of the fixed plate (412) and the toothed ring (423) is sleeved on the heat insulation pipe (417) that passes through the fixed plate (412).

7. The method for co-sintering of metal injection-molded mating parts according to claim 5, characterized in that: Two half-gears (424) are provided. The two half-gears (424) are arranged in a circular array with the toothed ring (423) as the center. The two half-gears (424) are respectively connected to the two transmission gears (422). Both half-gears (424) are tangent to the toothed ring (423).

8. The method for co-sintering of metal injection-molded mating parts according to claim 5, characterized in that: The transmission groove (425) is opened on the outer wall of the heat insulation pipe (417), and multiple transmission grooves (425) are equally spaced. The transmission protrusion (426) is set on the inner wall of the toothed ring (423), and multiple transmission protrusions (426) are provided. Multiple transmission protrusions (426) are slidably connected in multiple transmission grooves (425).

9. The method for co-sintering of metal injection-molded mating parts according to claim 5, characterized in that: One end of the drive shaft (427) is connected to the impeller of the fan (413). There are two fixed gears (428). The two fixed gears (428) are rotatably connected to the two side walls of the fixed plate (412) and the two fixed gears (428) are connected. One fixed gear (428) meshes with a drive gear (422). The end of the drive shaft (427) away from the fan (413) is connected to the other fixed gear (428).

10. The method for co-sintering of metal injection-molded mating parts according to claim 2, characterized in that: The longitudinal transverse component (43) includes a fixed cylinder (431) fixedly mounted on a fixed plate (412) and a protrusion (432) mounted on a heat insulation pipe (417). The heat insulation pipe (417) passes through the fixed cylinder (431). A spiral groove (433) is provided on the inner wall of the fixed cylinder (431). The protrusion (432) on the heat insulation pipe (417) is slidably connected in the spiral groove (433).

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