High-recycling feed regeneration method for metal injection molding

Abstract

The invention discloses a high-recycling feed regeneration method for metal injection molding, which comprises the following steps: 1, filling waste powder into a closed reaction kettle, introducing nitrogen to replace air, heating to 180 DEG C at a rate of 2 DEG C / min, preserving heat for 1 hour, injecting steam containing 0.5-1.5 wt% of nitric acid, catalytically decomposing a binder for 3-6 hours, and discharging a decomposed product; transferring the waste material powder to a fluidized bed reactor, heating to 450 DEG C in an argon environment at a rate of 5 DEG C / min, introducing pulse airflow, and keeping the temperature for 30 minutes; 2, carrying out surface passivation on the waste powder; 3, powder modification; 4, mixing the waste powder with a new material, and mixing with a binder; 5, extrusion injection; 6, degreasing and sintering; and crushing a drainage opening material, a defect material and the like obtained after injection, and repeating the steps 2-6. According to the high-recycling feed regeneration method for metal injection molding, the problems of carbon content control, powder oxidation and mechanical property stability of the regenerated material are solved through a gradient degreasing regeneration process, so that the regenerated product has good mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of metal injection molding, and particularly to a high-cycle utilization feedstock recycling method for metal injection molding. Background Art

[0002] In metal injection molding technology, feedstock is prepared by mixing metal powder and binder, and precision parts are obtained through injection, debinding, and sintering. Scrap materials (such as gate materials and defective parts) generated during the production process usually need to be pulverized again and incorporated into new feedstock for recycling.

[0003] Existing technical solutions include: 1. Mechanical pulverization + direct reuse Disadvantages: Residual binder is not treated. After 3 cycles, the tensile strength decreases by 15%, and the carbon content exceeds 0.5 wt%.

[0004] 2. Solvent extraction regeneration Disadvantages: A large amount of organic solvents are required, resulting in high costs and environmental pollution; the debinding efficiency is low (≥8 hours).

[0005] 3. Low-temperature vacuum debinding Disadvantages: The equipment is complex and it is difficult to scale up; the mixing ratio of recycled material and new material is limited (≤20%).

[0006] And the existing recycling processes have the following bottlenecks: 1. Out-of-control carbon content: Multiple thermal cycles lead to carbonized residue of the binder, affecting the performance of sintered parts (such as decreased plastic toughness).

[0007] 2. Powder oxidation: During the regeneration process, the metal powder is exposed to a high-temperature environment, and the surface oxide layer thickens, reducing the sintering density.

[0008] 3. Poor process compatibility: The fluidity and debinding efficiency of the recycled feedstock are significantly different from those of the new material, and the process parameters need to be adjusted greatly.

[0009] In view of the above considerations, it is necessary to design a high-cycle utilization feedstock preparation method that does not require complex equipment and can be applied on a large scale, solve the problems of carbon content control, powder oxidation, and mechanical property stability of the recycled feedstock, and achieve a recycled material incorporation ratio of ≥50% and still have good mechanical properties after multiple cycles of production. Summary of the Invention

[0010] The technical problem to be solved by the present invention is: to provide a high-cycle utilization feedstock recycling method for metal injection molding.

[0011] To solve the above technical problem, the technical solution adopted by the present invention is: a high-cycle utilization feedstock recycling method for metal injection molding, comprising the following steps: Step 1: Crush the waste materials into waste powder, load them into a closed reaction kettle, introduce nitrogen to displace air, heat up to 180°C at a heating rate of 2°C / min, maintain a constant temperature for 1 hour, and at the same time inject steam containing 0.5 - 1.5 wt% nitric acid to catalytically decompose the binder for 3 - 6 hours, and quickly discharge the decomposition products through a vacuum suction system; transfer the waste powder to a fluidized bed reactor, heat up to 450°C at a heating rate of 5°C / min in an argon environment, and introduce a pulsed gas flow, and keep warm for 30 minutes; Step 2: Passivate the surface of the waste powder; Step 3: Modify the waste powder to obtain recycled material; Step 4: Mix the recycled material and new material in proportion, and put them into a mixer together with the binder to obtain the feedstock; Step 5: Add the feedstock to an extruder, extrude it through the extruder and inject it into a mold to obtain a recycled part; Step 6: Subject the recycled part to degreasing and sintering in sequence to obtain a recycled product; Step 7: Crush the waste materials such as the sprue and defective parts obtained after injection in Step 4, and repeat Steps 2 to 6.

[0012] The beneficial effects of the present invention are as follows: The high-cycle utilization feedstock recycling method for metal injection molding solves the problems of carbon content control, powder oxidation, and mechanical property stability of the recycled material through a gradient degreasing recycling process, realizes that the incorporation ratio of the recycled material is ≥50%, and the mechanical properties of the recycled product after 5 cycles of production remain above 90% of the initial product. Description of the Drawings

[0013] Figure 1 It is a flow chart of the high-cycle utilization feedstock recycling method for metal injection molding according to Embodiment 1 of the present invention. Detailed Embodiments

[0014] To describe the technical content, achieved objectives and effects of the present invention in detail, the following is described in conjunction with the embodiments and accompanied by the drawings.

[0015] Please refer to Figure 1 , a high-cycle utilization feedstock recycling method for metal injection molding, including the following steps: Step 1: Crush the waste materials into waste powder, load them into a closed reaction kettle, introduce nitrogen to displace air, heat up to 180°C at a heating rate of 2°C / min, maintain a constant temperature for 1 hour, and at the same time inject steam containing 0.5 - 1.5 wt% nitric acid to catalytically decompose the binder for 3 - 6 hours, and quickly discharge the decomposition products through a vacuum suction system; transfer the waste powder to a fluidized bed reactor, heat up to 450°C at a heating rate of 5°C / min in an argon environment, and introduce a pulsed gas flow, and keep warm for 30 minutes; Step 2: passivate the surface of the waste powder; Step 3: modify the waste powder to obtain recycled material; Step 4: mix the recycled material and virgin material in proportion, and place them together with a binder into a mixer for mixing to obtain a feedstock; Step 5: add the feedstock into an extruder, extrude it through the extruder and inject it into a mold to obtain a recycled part; Step 6: subject the recycled part to degreasing and sintering in sequence to obtain a recycled product; Step 7: crush the waste materials such as the sprue and defective parts obtained after injection in Step 4, and repeat Steps 2 to 6.

[0016] As can be seen from the above description, the beneficial effects of the present invention are as follows: The high-cycle utilization feedstock recycling method for metal injection molding solves the problems of carbon content control, powder oxidation and mechanical property stability of recycled materials through a gradient degreasing recycling process, and realizes that the incorporation ratio of recycled materials ≥ 50% and the mechanical properties of the products after 5 cycles of production remain above 90% of the initial products.

[0017] Further, after Step 1, there is also a step: dynamically monitor the surface carbon layer stripping effect of the waste powder through a carbon-sulfur analyzer until the carbon content ≤ 0.3 wt%.

[0018] Further, the surface passivation process in Step 2 is as follows: immerse the waste powder in a 0.1 M citric acid-ethanol solution with a volume ratio of 1:3, perform ultrasonic treatment at 40 °C for 30 minutes, after centrifugal separation, dry it in a vacuum drying oven for 6 h to form a dense passivation film.

[0019] Further, the powder modification process in Step 3 is as follows: mix the passivated waste powder with 0.2-0.5 wt% of nano-yttrium oxide in a mixer for 2 h.

[0020] Further, the mixing ratio of the recycled material and virgin material in Step 4 is 50-70%:30-50%.

[0021] Further, the extrusion process in Step 5 includes: premixing at 160 °C; then raising the temperature to 180 °C, setting the screw speed of the injection machine to 200 rpm; finally lowering the temperature to 170 °C, setting the vacuum degree of the injection machine to -0.08 MPa.

[0022] Further, the injection process in Step 5 is as follows: set the injection pressure of the injection machine to 120 MPa, the injection pressure time to 2 s, quickly fill the mold cavity with the feedstock through the injection machine, and then perform pressure holding, the pressure holding pressure is 60 MPa, and the pressure holding time is 5 s.

[0023] Further, the degreasing process in Step Six is as follows: Argon with a flow rate of 5 L / min is introduced, heated to 600 °C at a rate of 3 °C / min, and held at this temperature for 1 hour.

[0024] Further, the sintering process in Step Six is as follows: The argon flow rate is reduced to 2 L / min, heated to 1350 °C at a rate of 5 °C / min, and held at this temperature for 2 hours.

[0025] Further, after Step Seven, Step Eight is also included: The recycled products obtained after multiple cycles are tested for density, tensile strength, and carbon content.

[0026] Please refer to Figure 1 , Example 1 of the present invention is: A high-cycle utilization feeding recycling method for metal injection molding, including the following steps: Step One, waste material gradient degreasing pretreatment. Select 316L stainless steel waste material (D 50 = 12 μm, sphericity 96%, oxygen content 0.25 wt%). After crushing the waste material into waste powder, it is loaded into a closed reaction kettle, and nitrogen is introduced to displace air until the oxygen content ≤ 0.1%. It is heated to 180 °C at a heating rate of 2 °C / min, maintained at a constant temperature for 1 hour, and at the same time, steam containing 1 wt% nitric acid (steam flow rate 10 L / min) is injected to catalytically decompose the binder for 5.5 h, and the decomposition products are quickly discharged through a vacuum suction system (vacuum degree ≤ 10 Pa); The waste powder is transferred to a fluidized bed reactor, heated to 450 °C at a heating rate of 5 °C / min in an argon environment (argon flow rate 20 L / min), and a pulsed gas flow (frequency 10 Hz, pulse amplitude ± 5 kPa) is introduced, and held at this temperature for 30 min; The surface carbon layer stripping effect of the waste powder is dynamically monitored by a carbon-sulfur analyzer until the carbon content ≤ 0.3 wt%.

[0027] Step Two, surface passivation of the waste powder. The surface passivation process is as follows: The waste powder is immersed in a 0.1 M citric acid-ethanol solution with a volume ratio of 1:3, ultrasonically treated at 40 °C for 30 minutes (frequency 40 kHz, power 200 W), after centrifugal separation, it is dried in a vacuum drying oven (60 °C, -0.1 MPa) for 6 h to form a dense passivation film.

[0028] Step Three, powder modification of the waste powder to obtain recycled material. The powder modification process is as follows: The passivated waste powder is mixed with 0.3 wt% of nano-yttrium oxide (particle size 50 nm) in a V-type mixer for 2 h (rotation speed 30 rpm).

[0029] Step Four: Mix the recycled material and the new material in a certain proportion, and put them into a mixer together with the binder to obtain the feedstock. Specifically, the components of the binder are: paraffin wax (65wt%), polyethylene (25wt%), and stearic acid (10wt%); the mixing ratio of the recycled material to the new material is 60%:40%.

[0030] Step Five: Add the feedstock into an extruder, extrude it through the extruder and inject it into a mold to obtain the recycled part. The extrusion process includes: premixing at 160°C to preliminarily soften the binder (paraffin wax + polyethylene) and avoid high-temperature degradation of the binder; secondly, the high-shear stage, raise the temperature to 180°C, set the screw speed of the injection machine at 200 rpm to break the powder agglomerates and improve the fluidity; finally, the homogenization stage, lower the temperature to 170°C, set the vacuum degree of the injection machine at -0.08 Mpa to remove bubbles and reduce internal stress. The injection process is: set the injection pressure of the injection machine at 120 MPa, the injection time at 2 s, and make the feedstock quickly fill the mold cavity through the injection machine, and then carry out pressure holding, the pressure holding pressure is 60 MPa, and the pressure holding time is 5 s to compensate for shrinkage and reduce flash.

[0031] Step Six: Subject the recycled part to degreasing and sintering in sequence to obtain the recycled product. The degreasing process is: introduce argon with a flow rate of 5 L / min, heat it up to 600°C at a rate of 3°C / min, and keep it warm for 1 hour to completely remove the residual binder. The sintering process is: reduce the argon flow rate to 2 L / min, heat it up to 1350°C at a rate of 5°C / min, and keep it warm for 2 hours to achieve densification.

[0032] Step Seven: Crush the waste materials such as the sprue and defective parts obtained after injection in Step Four to a particle size of ≤200 μm, and repeat Steps Two to Six.

[0033] Step Eight: Test the recycled products obtained after multiple cycles for density, tensile strength, carbon content, etc. The test shows that the density of the recycled product is 7.86 g / cm 3 , the carbon content is 0.22 wt% (close to the level of 0.2 wt% of the new material), and the tensile strength is 520 MPa; after 5 cycles, the tensile strength of the recycled product can maintain 95% of the initial product, which is significantly better than the traditional recycling process, and the tensile strength of the recycled product decreases by 24% after 5 cycles.

[0034] Please refer to Figure 1 , Example Two of the present invention is: A method for recycling a highly recyclable feedstock for metal injection molding, including the following steps: Step One: Gradient degreasing pretreatment of waste materials, select 316L stainless steel waste materials (D 50= 8 μm, sphericity 97%, oxygen content 0.18 wt%). After crushing the waste into waste powder, it is loaded into a closed reactor, and nitrogen is introduced to displace the air until the oxygen content ≤ 0.1%. It is heated to 180 °C at a heating rate of 2 °C / min and maintained at a constant temperature for 1 hour. At the same time, steam containing 1.5 wt% nitric acid (steam flow rate 10 L / min) is injected to catalytically decompose the binder for 3 h, and the decomposition products are quickly discharged through a vacuum suction system (vacuum degree ≤ 10 Pa). The waste powder is transferred to a fluidized bed reactor and heated to 450 °C at a heating rate of 5 °C / min in an argon environment (argon flow rate 20 L / min), and a pulsed gas flow (frequency 10 Hz, pulse amplitude ±5 kPa) is introduced, and the temperature is kept constant for 30 min. The surface carbon layer stripping effect of the waste powder is dynamically monitored by a carbon-sulfur analyzer until the carbon content ≤ 0.3 wt%.

[0035] Step 2: Surface passivation of the waste powder. The surface passivation process is as follows: The waste powder is immersed in a 0.1 M citric acid-ethanol solution with a volume ratio of 1:3, and ultrasonic treatment is carried out at 40 °C for 40 minutes (frequency 40 kHz, power 200 W). After centrifugal separation, it is dried in a vacuum drying oven (60 °C, -0.1 MPa) for 6 h to form a dense passivation film.

[0036] Step 3: Powder modification of the waste powder to obtain recycled material. The powder modification process is as follows: The passivated waste powder is mixed with 0.5 wt% of nano-yttrium oxide (particle size 50 nm) in a V-type mixer for 2 h (rotation speed 30 rpm).

[0037] Step 4: Mix the recycled material and the new material in proportion and place them in a mixer together with the binder to obtain the feedstock. Specifically, the components of the binder are: paraffin wax (68 wt%), polyethylene (22 wt%), stearic acid (10 wt%); the mixing ratio of the recycled material and the new material is 70%:30%.

[0038] Step 5: Add the feedstock to an extruder, extrude it through the extruder and inject it into a mold to obtain a recycled part. The extrusion process includes: premixing at 160 °C to preliminarily soften the binder (paraffin wax + polyethylene) to avoid high-temperature degradation of the binder; secondly, the high-shear stage, raise the temperature to 180 °C, set the screw speed of the injection machine to 200 rpm to break the powder agglomerates and improve the fluidity; finally, the homogenization stage, lower the temperature to 170 °C, set the vacuum degree of the injection machine to -0.08 Mpa to remove bubbles and reduce internal stress. The injection process is: set the injection pressure of the injection machine to 120 MPa, injection pressure time 2 s, and make the feedstock quickly fill the mold cavity through the injection machine, and then carry out pressure holding, the pressure holding pressure is 60 MPa, and the pressure holding time is 5 s to compensate for shrinkage and reduce flash.

[0039] Step 6: Subject the regenerated parts to degreasing and sintering in sequence to obtain the regenerated products. The degreasing process is as follows: Introduce argon with a flow rate of 5 L / min, heat it up to 600 °C at a rate of 3 °C / min, and hold the temperature for 1 hour to completely remove the residual binder. The sintering process is as follows: Reduce the argon flow rate to 2 L / min, heat it up to 1350 °C at a rate of 5 °C / min, and hold the temperature for 2 hours to achieve densification.

[0040] Step 7: Crush the waste materials such as the sprue materials and defective materials obtained after injection in Step 4 to a particle size ≤ 200 μm, and repeat Steps 2 to 6.

[0041] Step 8: Conduct tests on the density, tensile properties, carbon content, etc. of the regenerated products obtained after multiple cycles. The density of the regenerated products obtained from the tests is 7.84 g / cm 3 , the carbon content is 0.24 wt% (close to the level of 0.2 wt% of the new material), and the tensile strength is 500 MPa; after 5 cycles, the tensile strength of the regenerated products can maintain 93% of the initial products, which is significantly better than the traditional recycling process.

[0042] Comparative Example 1: A method for recycling and regenerating the feedstock in metal injection molding includes the following steps: Step 1: Select 316L stainless steel waste materials (D 50 = 12 μm, sphericity 96%, oxygen content 0.25 wt%), crush the waste materials into waste powder, and the particle size of the waste powder is 200 μm.

[0043] Step 2: Mix the regenerated materials (i.e., waste powder) with the new materials in a certain proportion, and place them in a mixer together with the binder to obtain the feedstock. Specifically, the components of the binder are: paraffin wax (65 wt%), polyethylene (25 wt%), stearic acid (10 wt%); the mixing ratio of the regenerated materials to the new materials is 30%:70%.

[0044] Step 3: Add the feedstock to an extruder, extrude and inject it into a mold through the extruder to obtain the regenerated parts. The injection process is as follows: Set the injection pressure of the injection machine to 120 MPa, the injection pressure time to 2 s, and use the injection machine to quickly fill the mold cavity with the feedstock, and then perform pressure holding. The pressure holding pressure is 60 MPa, and the pressure holding time is 5 s to compensate for shrinkage and reduce flash.

[0045] Step 4: Subject the regenerated parts to degreasing and sintering in sequence to obtain the regenerated products. The degreasing process is as follows: Introduce argon with a flow rate of 5 L / min, heat it up to 600 °C at a rate of 3 °C / min, and hold the temperature for 1 hour to completely remove the residual binder. The sintering process is as follows: Reduce the argon flow rate to 2 L / min, heat it up to 1350 °C at a rate of 5 °C / min, and hold the temperature for 2 hours to achieve densification.

[0046] Step Five: Crush the waste materials such as the gate materials and defective materials obtained after injection in Step Three to a particle size of ≤200 μm, and repeat Step Three to Step Four.

[0047] Step Six: Conduct tests on the recycled products obtained after multiple cycles, including density, tensile strength, and carbon content. The density of the recycled products obtained from the tests is 7.68 g / cm 3 , the carbon content is 0.60 wt%, and the tensile strength is 460 MPa; after 5 cycles, the tensile strength of the recycled products can maintain 74% of the initial products.

[0048] Comparative Example 2 A method for recycling feedstock in metal injection molding includes the following steps: Step One: Select 316L stainless steel waste materials (D 50 = 12 μm, sphericity 96%, oxygen content 0.25 wt%), crush the waste materials into waste powder, load them into a closed reaction kettle, introduce nitrogen to displace air until the oxygen content ≤ 0.1%, heat up to 180 °C at a heating rate of 2 °C / min, maintain a constant temperature for 1 hour, and at the same time inject steam containing 1 wt% nitric acid (steam flow rate 10 L / min) to catalytically decompose the binder for 5.5 h, and quickly discharge the decomposition products through a vacuum suction system (vacuum degree ≤ 10 Pa); extract the waste powder with trichloroethylene solvent for 48 hours to obtain recycled materials.

[0049] Step Two: Mix the recycled materials and new materials in proportion, and place them together with the binder into a mixer to mix and obtain the feedstock. Specifically, the components of the binder are: polyethylene glycol (60 wt%) and polymethyl methacrylate (40 wt%); the mixing ratio of the recycled materials and new materials is 40%:60%.

[0050] Step Three: Add the feedstock to an extruder, extrude and inject it into a mold through the extruder to obtain recycled parts. The extrusion process includes: premixing at 160 °C to preliminarily soften the binder and avoid high-temperature degradation of the binder; followed by a high-shear stage, raising the temperature to 180 °C, setting the screw speed of the injection machine at 200 rpm to break the powder aggregates and improve fluidity; finally, a homogenization stage, lowering the temperature to 170 °C, setting the vacuum degree of the injection machine at -0.08 Mpa to remove air bubbles and reduce internal stress. The injection process is: setting the injection pressure of the injection machine at 120 MPa and the injection time at 2 s, quickly filling the mold cavity with the feedstock through the injection machine, and then performing pressure holding, with the pressure holding pressure at 60 MPa and the pressure holding time at 5 s to compensate for shrinkage and reduce flash.

[0051] Step 4: Subject the regenerated parts to degreasing and sintering in sequence to obtain regenerated products. The degreasing process is as follows: Introduce argon with a flow rate of 5 L / min, heat it up to 600°C at a rate of 3°C / min, and keep it at this temperature for 1 hour to completely remove the residual binder. The sintering process is as follows: Reduce the argon flow rate to 2 L / min, heat it up to 1350°C at a rate of 5°C / min, and keep it at this temperature for 2 hours to achieve densification.

[0052] Step 5: Crush the waste materials such as the sprue materials and defective materials obtained after injection in Step 3 to a particle size of ≤200 μm, and repeat Steps 2 to 4.

[0053] Step 6: Conduct tests on the regenerated products obtained after multiple cycles, such as density, tensile strength, and carbon content. The density of the regenerated product obtained from the test is 7.78 g / cm 3 , the carbon content is 0.38 wt%, and the tensile strength is 480 MPa; the tensile strength of the regenerated product after 5 cycles can maintain 86% of the initial product.

[0054] The performance comparison table of the regenerated products obtained in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 is shown in Table 1 below:

[0055] Table 1 In summary, the high-cycle utilization feeding regeneration method for metal injection molding provided by the present invention solves the problems of carbon content control, powder oxidation, and mechanical property stability of the regenerated material through the gradient degreasing regeneration process, realizing that the incorporation ratio of the regenerated material is ≥50% and the mechanical properties of the regenerated product after 5 cycles of production remain above 90% of the initial product.

[0056] The above are only the embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A high-cycle utilization feeding regeneration method for metal injection molding, characterized in that It includes the following steps: Step 1: Crush the waste into waste powder and load it into a closed reaction kettle. Introduce nitrogen to displace air, heat it up to 180°C at a heating rate of 2°C / min, maintain a constant temperature for 1 hour, and simultaneously inject steam containing 0.5 - 1.5 wt% nitric acid to catalytically decompose the binder for 3 - 6 hours. Quickly discharge the decomposition products through a vacuum suction system; transfer the waste powder to a fluidized bed reactor, heat it up to 450°C at a heating rate of 5°C / min in an argon environment, and introduce a pulsed gas flow, and keep the temperature for 30 minutes; Step 2: Passivate the surface of the waste powder; Step 3: Modify the powder of the waste powder to obtain recycled material; Step 4: Mix the recycled material and new material in proportion, and place them together with the binder into a mixer to obtain a feedstock; Step 5: Add the feedstock to an extruder, extrude it through the extruder and inject it into a mold to obtain a recycled part; Step 6: Subject the recycled part to degreasing and sintering in sequence to obtain a recycled product; Step 7: Crush the waste materials such as the sprue and defective materials obtained after injection in Step 4, and repeat Steps 2 to 6.

2. A high-cycle utilization feedstock recycling method for metal injection molding according to claim 1, wherein, After Step 1, there is also a step: Dynamically monitor the surface carbon layer stripping effect of the waste powder through a carbon-sulfur analyzer until the carbon content ≤ 0.3 wt%.

3. A high-cycle utilization feedstock regeneration method for metal injection molding according to claim 1, characterized in that, The surface passivation process in Step 2 is: Immerse the waste powder in a 0.1M citric acid-ethanol solution with a volume ratio of 1:3, perform ultrasonic treatment at 40°C for 30 minutes, after centrifugal separation, dry it in a vacuum drying oven for 6 h to form a dense passivation film.

4. A high-cycle-reuse feedstock regeneration method for metal injection molding according to claim 1, characterized in that The powder modification process in Step 3 is: Mix the passivated waste powder with 0.2 - 0.5 wt% of nano-yttrium oxide in a mixer for 2 h.

5. A high-cycle utilization feedstock regeneration method for metal injection molding according to claim 1, characterized in that, The mixing ratio of the recycled material and new material in Step 4 is 50 - 70%:30 - 50%.

6. A high-cycle utilization feedstock recycling method for metal injection molding according to claim 1, characterized in that, The extrusion process in Step 5 includes: Premix at 160°C; then raise the temperature to 180°C, set the screw speed of the injection machine to 200 rpm; finally lower the temperature to 170°C, and set the vacuum degree of the injection machine to -0.08 MPa.

7. A high-cycle utilization feed regeneration method for metal injection molding according to claim 1, characterized in that, The injection process in Step 5 is: Set the injection pressure of the injection machine to 120 MPa, the injection pressure time to 2 s, quickly fill the mold cavity with the feedstock through the injection machine, and then perform pressure holding, the pressure holding pressure is 60 MPa, and the pressure holding time is 5 s.

8. A high-cycle utilization feed regeneration method for metal injection molding according to claim 1, characterized in that, The degreasing process in Step 6 is: Introduce argon with a flow rate of 5 L / min, heat it up to 600°C at a heating rate of 3°C / min, and keep the temperature for 1 hour.

9. A high-cycle utilization feedstock regeneration method for metal injection molding according to claim 1, characterized in that, The sintering process in Step 6 is: Reduce the argon flow rate to 2 L / min, heat it up to 1350°C at a heating rate of 5°C / min, and keep the temperature for 2 hours.

10. A high-cycle utilization feedstock regeneration method for metal injection molding according to claim 1, characterized in that, After Step 7, there is also Step 8: Test the density, tensile strength, and carbon content of the recycled products obtained after multiple cycles.

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