Injection molding aluminum alloy plastic-based feed and preparation process thereof

Abstract

The invention discloses an injection molding aluminum alloy plastic-based feed and a preparation process thereof, and the preparation process comprises the following steps: weighing aluminum alloy raw material powder according to the following percentage content, preparing a binder, preparing the feed, preparing a green body, carrying out catalytic degreasing, carrying out thermal de-sintering, carrying out heat treatment and the like. According to the method, the composition of the 6061 aluminum alloy and the special requirements of the injection molding process of the 6061 aluminum alloy are combined, the influence of factors such as the binder formula, the degreasing temperature, the degreasing time, the sintering temperature and the sintering time is optimized, the process steps of combining oxalic acid steam with a hot air circulation system and the like are introduced, and finally the comprehensive performance of the feed is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal alloy injection molding, in particular to an injection molding aluminum alloy plastic-based feedstock and a preparation process thereof. BACKGROUND

[0002] Metal powder injection molding technology (MIM for short) is an advanced manufacturing method combining high-precision plastic injection molding process with traditional powder metallurgy technology. It is mainly used for producing small metal parts with complex shape and high precision. The MIM process mainly includes four steps: first, finely mixed metal powder and high molecular binder (such as thermoplastic polymer) to make feedstock; then, the feedstock is injected into the mold after heating and cooled to form the preliminary shape of the required part; next, the debinding step removes most of the binder through chemical or thermal treatment; finally, the metal powder particles in the part are combined through high-temperature sintering, and the density and strength are greatly improved, and finally a nearly fully dense metal part is obtained.

[0003] 6061 aluminum alloy (main alloying elements are Mg and Si, typical state is T6) is widely used in aerospace, automobile, industrial machinery and sports equipment due to its high strength, excellent weldability and easy processability. The traditional production process of aluminum alloy includes melting and casting, extrusion molding, die casting and powder metallurgy, etc., among which hot extrusion and forging are the main production methods. However, when it comes to the manufacture of small and complex-shaped precision parts, these traditional processes face challenges. For example, die casting can guarantee high product density and precision, but it is difficult and costly to produce complex small parts; in contrast, MIM process is more suitable because it uses smaller raw material powder and has higher shape design freedom. However, when MIM process is applied to 6061 aluminum alloy, due to the influence of aluminum alloy composition, binder composition, debinding temperature, debinding time, sintering temperature, sintering time and other factors, the product has the problems of high sintering residual carbon content, low density and poor mechanical properties. SUMMARY

[0004] In order to solve the above-mentioned problems, the present application provides an injection molding aluminum alloy plastic-based feedstock preparation process, which comprises the following steps: The aluminum alloy raw material powder is weighed according to the following percentage content: silicon 0.4-0.8%, copper 0.15-0.40%, magnesium 0.9-1.2%, chromium 0.04-0.35%, iron <0.15%, manganese <0.15%, zinc <0.25%, titanium <0.05%, and the rest is aluminum; Preparation of binder; Preparation of feedstock: aluminum alloy raw material powder and binder are mixed in an atmosphere-protected internal mixer, mixed at a temperature of 150-190℃ for 60-90min, and then extruded and granulated to obtain the feedstock; a reasonable mixing temperature can avoid thermal degradation of the binder and ensure that the binder is fully melted; Preparation of green body: the feedstock is melted and plasticized, then injected into a mold cavity, cooled and shaped, and taken out to obtain a green body; Catalytic debinding: oxalic acid vapor is injected into a hot air circulation system, and the oxalic acid reacts with the binder in the green body under forced convection to cause catalytic cracking; Thermal debinding and sintering: the green body after catalytic debinding is placed in a heating device with an inert protective gas atmosphere, and is first gradually heated to 420-450℃ for debinding, and then gradually heated to 590-610℃ for sintering treatment to obtain a sintered part; Heat treatment: the sintered part is solution treated at 510-550℃ for 1-2h and then water cooled, and then aged at 160-180℃ for 6-12h; a reasonable solution temperature and solution time can ensure that a supersaturated solid solution is obtained, and a reasonable aging temperature and aging time are helpful for the precipitation of strengthening phase Mg2Si to improve the mechanical properties of the finished product. Here, solution treatment refers to heating the alloy material to a specific temperature range, keeping it for a certain period of time to make as many elements as possible dissolved in the matrix to form a uniform solid solution; here, aging refers to a heat treatment process in which the alloy material after solution treatment and quenching is kept at a lower temperature for a certain period of time to promote the precipitation of a second phase from the supersaturated solid solution, thereby enhancing the strength and hardness of the material.

[0005] Preferably, the preparation of the binder comprises the following steps: mixing 44-74 parts by mass of polyformaldehyde, 5-9 parts of maleic anhydride grafted polypropylene, 4-10 parts of polyethylene glycol, 10-20 parts of polyvinyl alcohol, 2-6 parts of silane coupling agent KH550, 1-3 parts of nano-talc powder, 2-4 parts of triethyl citrate, 1-2 parts of epoxy soybean oil, and 1-2 parts of sodium bicarbonate.

[0006] Preferably, the polyethylene glycol is any one of PEG-400, PEG-2000, and PEG-4000.

[0007] Preferably, the aluminum alloy raw material powder D10 is 3-5 μm, D50 is 10-12 μm, and D90 is 10-25 μm; D10 of 3-5 μm means that 10% of the particles in the entire aluminum alloy raw material have a particle size of less than or equal to 3-5 μm, D50 of 10-12 μm means that 50% of the particles in the entire aluminum alloy raw material have a particle size of less than or equal to 10-12 μm, and D90 of 10-25 μm means that 90% of the particles in the entire aluminum alloy raw material have a particle size of less than or equal to 10-25 μm; such a particle size distribution characteristic has good matching with the injection molding process, which can ensure the flowability of the feeding system and is conducive to promoting the densification behavior in the subsequent sintering stage.

[0008] Preferably, in the preparation of the preparation feeding step, the aluminum alloy raw material and the binder are mixed in a volume ratio of 55.6-60%:40-44.4%; too high a proportion of the binder will result in insufficient green body strength after injection, high porosity after debinding, high shrinkage rate during sintering, and difficulty in obtaining a high-density metal part; too low a proportion of the binder will result in high viscosity and poor flowability of the feed, and problems such as rough surface and flow marks of the metal part.

[0009] Preferably, in the preparation of the green body step, the melting plasticization temperature is 160-190℃; a reasonable melting plasticization temperature can not only avoid thermal degradation of the binder but also ensure good flowability of the binder and avoid uneven filling.

[0010] Preferably, in the catalytic debinding step, the temperature of the hot air circulation system is controlled at 120-130℃, and the supply rate of oxalic acid vapor is 3-7 g / min; suitable catalytic reaction temperature and oxalic acid vapor supply rate can not only promote rapid and uniform removal of the binder but also avoid rapid debinding that causes the green body to deform or have structural defects.

[0011] Preferably, in the thermal debinding and sintering step, the temperature is gradually increased to 420-450℃ as follows: first increased to 160-170℃, kept for 30-60 min to ensure that the low molecular components fully escape, then increased to 250-280℃, kept for 90-120 min to control the decomposition rate and reduce structural defects, then continuously increased to 350-380℃, kept for 90-120 min to remove residual binder, and then increased to 420-450℃, kept for 30-60 min; too high a temperature in this process will cause the embryo to deform, and too high a temperature in this process will prematurely enter the sintering stage.

[0012] Preferably, in the heat debindering step, the sintering process is as follows: continue to heat from 420~450℃ to 580~600℃, maintain the vacuum heating, and keep the temperature for 40~60min, the temperature is too high, which may cause local melting; continue to heat to 590~610℃, and keep the temperature for 2~3h, then cool to 190~210℃, the temperature and time control is suitable, which can realize sufficient sintering and avoid producing coarse grains.

[0013] Another purpose of the present application is to provide an injection molded aluminum alloy plastic-based feedstock prepared by the above-mentioned injection molding aluminum alloy plastic-based feedstock preparation process.

[0014] The beneficial effects are as follows: the new compounded binder added by the present application for the injection molding process of 6061 aluminum alloy plastic-based feedstock not only has strong intermolecular force and good interface compatibility with 6061 aluminum alloy, but also has decomposition temperature matching with the sintering temperature of 6061 aluminum alloy, high debinding efficiency, less sintering residual carbon, good fluidity, and compatibility with subsequent solid solution and aging heat treatment process, which can significantly improve the density and mechanical properties of 6061 aluminum alloy plastic-based feedstock. Specifically, the new compounded binder mainly uses polyformaldehyde as the main binder, which has low viscosity and excellent melt flowability. Polyethylene glycol and polyvinyl alcohol with low viscosity and easy melting are used to significantly reduce the melt viscosity of the whole binder. The added triethyl citrate has low viscosity and high plasticizing efficiency, and has good compatibility with polyethylene glycol. Combined with the good dispersibility of nano-talc powder, the rheological property of the feedstock is adjusted to ensure that the feedstock can quickly fill the complex cavity during injection molding, laying a complete blank foundation for subsequent processing. The amino functional group of silane coupling agent KH550 forms a chemical bond with aluminum and magnesium elements in 6061 aluminum alloy, and the maleic anhydride group of PP-g-MAH and the epoxy group in the molecule of epoxy soybean oil react with the aluminum oxide film on the surface of 6061 aluminum alloy to enhance the interface bonding force between the metal powder and the binder, reduce the risk of cracking or delamination after debinding, improve the uniformity and stability of the feedstock, and greatly reduce the risk of component segregation in the blank. The decomposition temperature range of the main component of the binder, polyformaldehyde, is highly matched with the pre-sintering temperature of 6061 aluminum alloy. Oxalic acid is used in combination with hot air to accelerate the removal of polyformaldehyde, polyvinyl alcohol, and polyethylene glycol. Then, sodium bicarbonate is used to form a microporous network by decomposing gas, which promotes the diffusion and discharge of decomposition products such as formaldehyde and carbon dioxide, significantly shortens the debinding time, reduces the carbon residue in the blank after debinding, and the residual carbon content in the blank after sintering is less than 0.02%. At the same time, it promotes the uniform precipitation of Mg2Si strengthening phase when the carbon element forms brittle Al4C3 phase with aluminum, finally makes the hardness of 6061 aluminum alloy feedstock reach more than 100HV, the tensile strength reach more than 310MPa, the yield strength reach more than 270MPa, and the elongation after heat treatment reach more than 11%, which significantly optimizes the comprehensive mechanical properties of 6061 aluminum alloy plastic-based feedstock injection molded products. DETAILED DESCRIPTION

[0015] The application will be further described in connection with the following detailed description of specific embodiments so that those skilled in the art might better understand the application.

[0016] The following examples are intended to be illustrative only and are not intended to limit the scope of the present application. Based upon a review of the specific examples contained herein, one of ordinary skill in the art, without undue experimentation, can ascertain other examples that are within the scope of the present application.

[0017] In the embodiments of the present application, all raw material components are commercially available products well known to those skilled in the art, unless otherwise specified. In the embodiments of the present application, the technical means used are conventional means well known to those skilled in the art, unless otherwise specified.

[0018] Raw material sources: Polyoxymethylene (POM), model number Japan Bao Li M270-44, purchased from Shanghai Handar New Materials Co., Ltd.; Maleic anhydride grafted polypropylene (PP-g-MAH), purchased from Shanghai Kaijin Chemical Co., Ltd.; Polyethylene glycol, PEG-400, PEG-2000, PEG-4000, all purchased from Haian Petrochemical Factory in Jiangsu Province; Polyvinyl alcohol (PVA), purchased from Chengdu Lanji Technology Co., Ltd.; Silane coupling agent KH550, purchased from Jinan Xiangfeng Weiyeh Chemical Co., Ltd.; Nanoscale talc powder, purchased from Foshan Huokui Refractory Materials Co., Ltd.; Triethyl citrate (TEC), purchased from Jinan Xiangfeng Weiyeh Chemical Co., Ltd.; Epoxy soybean oil (ESO), purchased from Shandong Kexing Chemical Co., Ltd.; Sodium bicarbonate, purchased from Quanzhou Halli Chemical Co., Ltd.; Paraffin wax, purchased from Shandong Xufa Chemical Co., Ltd.; Silane coupling agent KH560, purchased from Shandong Yuanjin New Materials Co., Ltd.; The remaining reagents are all conventional commercially available.

[0019] Example 1 The present embodiment provides a preparation process for injection molding aluminum alloy plastic-based feed, comprising the following steps: The aluminum alloy raw material powder is weighed according to the following percentage content: silicon 0.4%, copper 0.15%, magnesium 0.9%, chromium 0.04%, and the rest is aluminum; wherein the D10 of the aluminum alloy raw material powder is 3 μm, the D50 is 10 μm, and the D90 is 10 μm; Preparation of binder: the binder is prepared by mixing 74 parts of polyformaldehyde, 5 parts of maleic anhydride grafted polypropylene, 4 parts of polyethylene glycol PEG-400, 10 parts of polyvinyl alcohol, 2 parts of silane coupling agent KH550, 1 part of nano-talc powder, 2 parts of triethyl citrate, 1 part of epoxy soybean oil, and 1 part of sodium bicarbonate; Preparation of feedstock: aluminum alloy raw material powder and binder are mixed in a volume ratio of 55.6%:44.4% in a banbury mixer under argon atmosphere protection, and mixed at a temperature of 150°C for 60 min to form a uniform paste, which is then extruded and granulated to obtain 1mm feedstock; Preparation of green body: the feedstock is injected into a mold cavity after being melted and plasticized in an injection molding machine at 160°C, and then cooled and shaped to obtain a green body; Catalytic debinding: oxalic acid vapor is injected into a hot air circulation system at a supply rate of 3g / min at 120°C, and the oxalic acid reacts with the binder in the green body to cause catalytic cracking in a forced convection environment; Thermal debinding and sintering: the green body after catalytic debinding is placed in a graphite vacuum furnace with an argon protection gas atmosphere, and is first gradually heated to 420°C for debinding, and then gradually heated to 590°C for sintering treatment to obtain a sintered part; more specifically, the process is as follows: first heated to 160°C, held for 30 min, then heated to 250°C, held for 90 min, then heated to 350°C, held for 90 min, then heated to 420°C, held for 30 min, then heated to 580°C, held for 40 min in vacuum, then heated to 590°C, held for 2h, and then cooled to 190°C; Heat treatment: the sintered part is solution treated at 510°C for 1h and then water cooled, and then aged at 160°C for 6h.

[0020] Example 2 The present embodiment provides a process for preparing an injection molded aluminum alloy plastic-based feedstock, comprising the following steps: The aluminum alloy raw material powder is weighed according to the following percentage content: silicon 0.6%, copper 0.25%, magnesium 1.1%, chromium 0.2%, iron 0.1%, manganese 0.1%, zinc 0.12%, titanium 0.03%, and the rest is aluminum; wherein the D10 of the aluminum alloy raw material powder is 4μm, the D50 is 11μm, and the D90 is 17μm; Preparation of binder: the binder is prepared by mixing 74 parts of polyformaldehyde, 5 parts of maleic anhydride grafted polypropylene, 4 parts of polyethylene glycol PEG-400, 10 parts of polyvinyl alcohol, 2 parts of silane coupling agent KH550, 1 part of nano-talc powder, 2 parts of triethyl citrate, 1 part of epoxy soybean oil, and 1 part of sodium bicarbonate; Preparation of feedstock: aluminum alloy raw material powder and binder were mixed in a mixer under argon atmosphere protection at a volume ratio of 58%:42%, and mixed at a temperature of 170℃ for 75 min to form a uniform paste, which was then extruded and granulated to obtain 4mm feedstock; Preparation of green body: the feedstock was injected into the mold cavity after melting and plasticizing in an injection molding machine at 175℃, and then cooled and shaped to obtain a green body; Catalytic debinding: oxalic acid vapor was injected into a hot air circulation system at a supply rate of 5g / min at 125℃, and the oxalic acid reacted with the binder in the green body to cause catalytic cracking in a forced convection environment; Thermal debinding and sintering: the green body after catalytic debinding was placed in a graphite vacuum furnace with argon protection gas atmosphere, and first gradually heated to 430℃ for debinding, and then gradually heated to 595℃ for sintering treatment to obtain a sintered part; more specifically, the process was as follows: first heated to 165℃, held for 45 min, then heated to 265℃, held for 105 min, then heated to 365℃, held for 105 min, then heated to 435℃, held for 45 min, then continued to heat to 590℃, continued to maintain vacuum sintering and held for 50 min; then heated to 595℃ and held for 2.5h, and then cooled to 200℃; Heat treatment: the sintered part was solution treated at 530℃ for 1.5h and then water cooled, and then aged at 170℃ for 9h.

[0021] Example 3 The present example provides a process for preparing an injection molded aluminum alloy plastic-based feedstock, comprising the following steps: The aluminum alloy raw material powder was weighed according to the following percentage content: silicon 0.8%, copper 0.40%, magnesium 1.2%, chromium 0.35%, iron 0.15%, manganese 0.15%, zinc 0.25%, titanium 0.05%, and the rest was aluminum; wherein the D10 of the aluminum alloy raw material powder was 5μm, the D50 was 12μm, and the D90 was 25μm; Preparation of binder: the binder was prepared by mixing 44 parts of polyformaldehyde, 9 parts of maleic anhydride grafted polypropylene, 10 parts of polyethylene glycol PEG-4000, 20 parts of polyvinyl alcohol, 6 parts of silane coupling agent KH550, 3 parts of nano-talc powder, 4 parts of triethyl citrate, 2 parts of epoxy soybean oil, and 2 parts of sodium bicarbonate; Preparation of feedstock: aluminum alloy raw material powder and binder were mixed in a mixer under argon atmosphere protection at a volume ratio of 60%:40%, and mixed at a temperature of 190℃ for 90 min to form a uniform paste, which was then extruded and granulated to obtain 6mm feedstock; Preparation of green body: the feedstock was injected into the mold cavity after melting and plasticizing in an injection molding machine at 190℃, and then cooled and shaped to obtain a green body; Catalytic debinding: oxalic acid vapor was injected into a hot air circulation system at 130℃ at a supply rate of 7g / min, and the oxalic acid reacted with the binder in the green body in a forced convection environment to cause catalytic cracking; Thermal debinding and sintering: the green body after catalytic debinding was placed in a graphite vacuum furnace with an argon protective gas atmosphere, and was gradually heated to 450℃ for debinding and then gradually heated to 600℃ for sintering treatment to obtain a sintered part; more specifically, the process was as follows: first heated to 170℃ and held for 60min, then heated to 280℃ and held for 120min, then continued to heat to 380℃ and held for 120min, then continued to heat to 450℃ and held for 60min, then continued to heat to 600℃ and held for 60min; then continued to heat to 610℃ and held for 3h, and then cooled to 210℃; Thermal treatment: the sintered part was solutionized at 550℃ for 2h and then water-cooled, and then aged at 180℃ for 12h.

[0022] Comparative Example 1 This comparative example differs from Example 2 in that paraffin wax was used to replace the binder in Example 2, and the binder preparation step was omitted, and the other components and experimental steps were the same as in Example 2.

[0023] Comparative Example 2 This comparative example differs from Example 2 in that maleic anhydride grafted polypropylene was not added in the binder preparation step, and the other components and experimental steps were the same as in Example 2.

[0024] Comparative Example 3 This comparative example differs from Example 2 in that silane coupling agent KH560 was used to replace silane coupling agent KH550 in the binder preparation step, and the other components and experimental steps were the same as in Example 2.

[0025] Comparative Example 4 This comparative example differs from Example 2 in that sodium bicarbonate was not added in the binder preparation step, and the other components and experimental steps were the same as in Example 2.

[0026] Comparative Example 5 This comparative example differs from Example 2 in that the melt plasticization temperature was 210℃ in the green body preparation step, and the other components and experimental steps were the same as in Example 2.

[0027] Comparative Example 6 This comparative example differs from Example 2 in that the gradual heating to 460℃ for debinding in the thermal debinding and sintering step was as follows: first heated to 180℃ and held for 20min, then heated to 290℃ and held for 70min, then continued to heat to 390℃ and held for 70min, then continued to heat to 460℃ and held for 20min, and the other components and experimental steps were the same as in Example 2.

[0028] Comparative Example 7 The difference between this comparative example and Example 2 is that, in the heat debinding and sintering step, the temperature is gradually increased to 620℃, and the sintering process is as follows: continue to increase the temperature from 435℃ to 610℃, maintain the vacuum sintering, and keep the temperature for 30min, continue to increase the temperature to 620℃, and keep the temperature for 1.5h, then decrease the temperature to 180℃, and other components and experimental steps are the same as those of Example 2.

[0029] The feedstocks prepared in Examples 1-3 and Comparative Examples 1-7 were tested for performance.

[0030] Test method: The sintering density was tested according to the Archimedes drainage method in GB / T 3850-2015; The residual carbon content was tested according to the inert gas melting method in GB / T 38981-2020 Clause 4.1; The sintering oxygen content was tested according to GB / T 20975.25-2008 "Chemical analysis method for aluminum and aluminum alloy Part 25: Determination of oxygen content Inert gas fusion-infrared absorption method"; The heat treatment hardness was tested according to GB / T 4340.1-2009 "Metallic materials Vickers hardness test Part 1: Test method"; The tensile strength, yield strength and elongation after heat treatment were all tested according to GB / T 228.1-2021 standard; Table 1 Test results of feedstock

[0031] From the above table, it can be seen that the aluminum alloy feedstocks prepared in Examples 1-3 all perform excellently in various performances, and the sintering density reaches 2.7g / cm 3The above, the residual carbon content is as low as 0.02wt% or less, the sintering oxygen content is as low as 0.15wt% or less, the hardness reaches 100HV or more, the tensile strength reaches 310MPa or more, the yield strength reaches 270MPa or more, and the elongation after heat treatment reaches 11% or more. Since the new compounded binder added in each of the above examples is designed for the injection molding process requirements of the 6061 aluminum alloy plastic-based feedstock, it not only has strong intermolecular force and good interface compatibility with 6061 aluminum alloy, but also has a decomposition temperature matching the sintering temperature of 6061 aluminum alloy, which can effectively improve the debinding efficiency and reduce the sintering residual carbon, while being compatible with subsequent solid solution and aging heat treatment processes, promoting the uniform precipitation of Mg2Si strengthening phase, and significantly improving the density and mechanical properties of 6061 aluminum alloy plastic-based feedstock. In Comparative Example 1, the binder in Example 2 is replaced with paraffin wax, the sintering density is reduced to 2.52g / cm³, the residual carbon content is increased to 0.18wt%, the tensile strength is only 245MPa, and the elongation after heat treatment is only 5.3%, indicating that paraffin wax has serious debinding residue and poor interface bonding force, resulting in a significant decline in the mechanical properties of the feedstock. In Comparative Example 2, the maleic anhydride grafted polypropylene is missing, the sintering oxygen content increases, and the hardness and tensile strength decrease, which may be due to the weakening of the interface bonding force between the binder and the metal powder after the maleic anhydride grafted polypropylene is missing. In Comparative Example 3, silane coupling agent KH560 is used instead of silane coupling agent KH550, and the density decreases, the residual carbon content increases, and the mechanical properties decrease, which may be due to the difficulty of forming effective chemical bonds between the epoxy group contained in silane coupling agent KH560 and aluminum, magnesium elements in the aluminum alloy, and polyformaldehyde, maleic anhydride grafted polypropylene components, resulting in a decrease in the interface compatibility between the metal powder and the binder, and a decrease in the uniformity of the feedstock. In Comparative Example 4, without adding sodium bicarbonate, the decomposition product is blocked, resulting in an increase in residual carbon content. In Comparative Example 5, the melting plasticization temperature is too high, causing the binder to degrade, resulting in a decrease in the flowability of the feedstock, and a decrease in the density due to insufficient filling. In Comparative Example 6 and Comparative Example 7, the density decreases, and the mechanical strength and elongation decrease, which may be due to the deformation of the blank or the grain coarsening caused by improper temperature and time control during debinding and sintering. The above comparative examples fully demonstrate that the optimization of the binder formulation and process parameters plays a key role in improving the comprehensive performance of aluminum alloy injection molding feedstock.

[0032] In summary, the present application optimizes the influence of binder formulation, debinding temperature, debinding time, sintering temperature, sintering time, etc. in combination with the composition of 6061 aluminum alloy and the special requirements of its injection molding process, and introduces the process steps of oxalic acid vapor combined with hot air circulation system, etc. Finally, the density and mechanical properties of the feedstock are significantly improved.

[0033] The above merely illustrates the embodiments of the present application, but should not be taken as limitations. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the scope of claims of the present application.

Claims

1. A process for the production of an injection moulded aluminium alloy plastic based feedstock, characterised in that, The method comprises the following steps: The aluminum alloy raw material powder is prepared according to the following percentage content: 0.4-0.8% of silicon, 0.15-0.40% of copper, 0.9-1.2% of magnesium, 0.04-0.35% of chromium, <0.15% of iron, <0.15% of manganese, <0.25% of zinc, <0.05% of titanium, and the rest of aluminum; The binder is prepared; The feedstock is prepared by adding the aluminum alloy raw material powder and the binder into an atmosphere-protected internal mixer, mixing, and mixing at a temperature of 150-190 DEG C for 60-90 min to form a uniform paste, and then extruding and granulating to obtain the feedstock; The green body is prepared by injecting the molten and plasticized feedstock into a mold cavity, cooling and shaping, and taking out to obtain the green body; The catalytic debinding is performed by injecting oxalic acid vapor into a hot air circulation system to make the oxalic acid and the binder in the green body undergo a catalytic cracking reaction in a forced convection environment; The thermal debinding and sintering is performed by placing the green body after the catalytic debinding into a heating device with an inert protective gas atmosphere, gradually heating to 420-450 DEG C for debinding, and then gradually heating to 590-610 DEG C for sintering treatment to obtain a sintered part; The thermal treatment is performed by solid-solutionizing the sintered part at 510-550 DEG C for 1-2 h, water cooling, and then aging at 160-180 DEG C for 6-12 h.

2. The process for producing an injection molded aluminum alloy plastic-based feedstock according to claim 1, wherein The binder is prepared by mixing 44-74 parts of polyformaldehyde, 5-9 parts of maleic anhydride grafted polypropylene, 4-10 parts of polyethylene glycol, 10-20 parts of polyvinyl alcohol, 2-6 parts of silane coupling agent KH550, 1-3 parts of nano-talcum powder, 2-4 parts of triethyl citrate, 1-2 parts of epoxy soybean oil, and 1-2 parts of sodium bicarbonate.

3. The injection-molding aluminum alloy plastic-based feedstock preparation process of claim 2, wherein, The polyethylene glycol is any one of PEG-400, PEG-2000, and PEG-4000.

4. The process of claim 1 wherein the injection molded aluminum alloy plastic-based feedstock is prepared by the process comprising: The aluminum alloy raw material powder has a D10 of 3-5 um, a D50 of 10-12 um, and a D90 of 10-25 um.

5. The process of claim 1 wherein the injection molded aluminum alloy plastic-based feedstock is prepared by the process comprising: In the preparation of the feedstock, the aluminum alloy raw material and the binder are mixed at a volume ratio of 55.6-60%:40-44.4%.

6. The process of claim 1 wherein the injection molded aluminum alloy plastic-based feedstock is prepared by the process comprising: In the preparation of the green body, the temperature of the molten and plasticized material is 160-190 DEG C.

7. The injection molding aluminum alloy substrate feeding process according to claim 1, characterized in that, In the catalytic debinding, the temperature of the hot air circulation system is controlled at 120-130 DEG C, and the supply rate of the oxalic acid vapor is 3-7 g / min.

8. The process of claim 1 wherein the injection molded aluminum alloy plastic-based feedstock is prepared by the process comprising: In the thermal debinding and sintering, the gradual heating to 420-450 DEG C for debinding is performed by first heating to 160-170 DEG C, holding for 30-60 min, then heating to 250-280 DEG C, holding for 90-120 min, continuing to heat to 350-380 DEG C, holding for 90-120 min, and then heating to 420-450 DEG C, holding for 30-60 min.

9. The process of claim 1 wherein the injection molded aluminum alloy plastic-based feedstock is prepared by, In the heat debindering step, the temperature is gradually increased to 590-610 DEG C for sintering treatment as follows: from 420-450 DEG C, the temperature is continuously increased to 580-600 DEG C, and the sintering is maintained in vacuum for 40-60 min; the temperature is continuously increased to 590-610 DEG C, and the sintering is maintained for 2-3 h, and then the temperature is decreased to 190-210 DEG C.

10. An injection molded aluminum alloy plastic-based feedstock, characterized in that, The injection-molded aluminum alloy plastic-based feedstock is prepared according to the process of any one of claims 1 to 9.

Images