Copper-tin alloy 3D printing forming method based on infiltration method

Abstract

The invention relates to a process method for preparing a copper-tin alloy by combining a 3D printing technology and an infiltration method, which comprises the following steps: preparing a 3D printing wire containing a mixture of copper-tin powder and a binder, and sintering the copper-tin alloy by utilizing 3D printing and acid degreasing processes and adopting the infiltration method. The preparation method comprises the following steps: (1) adding a mixture of polyformaldehyde, polypropylene, zinc oxide, dioctyl phthalate and dibutyl phthalate into 80% by mass of copper powder and 20% by mass of tin powder according to a certain proportion, pouring into a kneading machine, heating to 160 DEG C, and internally mixing to prepare a uniform mixture; (2) adding the granules into a screw injection molding machine, and carrying out pressurized injection molding to obtain plastic wires with the diameter phi of 1.75 mm; (3) preparing a biscuit by adopting 3D printing; (4) degreasing the biscuit by adopting an acidic degreasing process; and (5) sintering to obtain the copper-tin alloy. According to the method, the copper-tin alloy is prepared through 3D printing and infiltration sintering, a mold does not need to be poured, and the method is suitable for flexible production of small-batch complex alloy components.

Description

Technical Field

[0001] The present invention relates to the field of metal 3D printing technology, and specifically to a method for manufacturing copper-tin alloy molding by melt infiltration and its preparation process. Compared with the traditional method for preparing copper-tin alloy, the copper-tin alloy is prepared by mixing different single metal powders and sintering them by melt infiltration; the metal element ratio of different single metal powders can be freely adjusted, and no special casting mold is required. The production process is pollution-free and suitable for flexible production of small batches and complex copper-tin alloy components. Background Art

[0002] Copper and its copper alloys are widely used metal materials in industry. They play an important role in industrial production due to their excellent properties such as good electrical conductivity, thermal conductivity and corrosion resistance. Among them, copper-tin alloy has excellent electrical conductivity, thermal conductivity, wear resistance and ductility, and has become the preferred material for the preparation of lubricating and wear-resistant parts. It is often widely used in engine bearings, turbines and bushings, brushes and other parts.

[0003] At present, the mainstream preparation methods of copper-tin alloys, such as tin bronze, include casting and metal injection molding (MIM). These traditional processes are suitable for large-scale manufacturing of metal parts, but due to the complexity of the process and the high cost of equipment manufacturing, it is difficult to produce small batches of complex-shaped parts. In recent years, with the increasing maturity of technologies such as additive manufacturing (AM), novel additive manufacturing technologies such as the use of composite filaments combining metal and polymer (such as fused deposition 3D printing) to manufacture small metal parts have attracted the attention of more scholars and scientific researchers.

[0004] Fused Deposition Modeling (FDM) is a method in which a hot-melt material is heated and melted at the 3D printing nozzle and extruded, and the extruded filling filament is deposited in a specified position. It is widely used in desktop plastic 3D printers due to its low printing cost, simple forming method, and simple print head structure. Compared with traditional 3D printing feed, there are relatively few studies on using metal feed for FDM 3D printing. Luquan Ren et al. proposed an extrusion 3D printing technology based on a paraffin binder system. Using copper powder and wax-based binder as raw materials, pure copper samples were successfully prepared. The sample hardness was 63.04HV and the density was 8.15g / cm 3 , the tensile strength is 6.73±0.6MPa.

[0005] The Chinese patent "A method for preparing metal materials based on 3D printing" (application number: CN202211411517.0, publication number: CN115921888A, publication date: 2023.04.07) discloses a preparation technology for 3D printed metal materials, which includes a variety of alloys including copper-tin alloys. The invention controls the porosity of the printed parts by grading metal mixed powders and controls the amount of infiltration materials used. The technology uses alloy powders for liquid phase sintering to obtain the corresponding alloys; however, the invention cannot directly adjust the ratio between different metal elements and is not suitable for flexible production of multi-element alloys with different metal element ratios.

[0006] The Chinese patent "A method for preparing a high-strength wear-resistant copper-tin alloy" (application number: CN202311555903.1, publication number: CN117845079A, publication date: 2024.04.09) discloses a preparation technology for a copper-tin alloy, which is to mix the alloy raw materials, place them in a high-temperature furnace for smelting and casting to obtain an ingot, and then perform a three-stage annealing process on the ingot under a set temperature gradient, and finally perform a solid solution treatment and cold rolling to obtain a copper-tin alloy. The technology requires high temperatures, complex process flow, and mold shaping and casting, which is not suitable for the flexible production of small and complex parts.

[0007] It can be seen that the defects of the existing technology include: it is impossible to flexibly adjust the ratio between different metal elements, making it difficult to manufacture multi-component alloys with different ratios of metal elements; the casting method has a high temperature and takes a long time, the process is relatively cumbersome, and has certain technical requirements for operators; and the method requires the manufacture of molds outside, which easily leads to material waste.

[0008] The reason for the above defects is that the casting method includes the steps of melting, pouring, cooling, etc., which is relatively cumbersome and complicated to make, resulting in high technical requirements for operators. Due to the particularity of the casting method, it is necessary to use clay, gypsum and other materials to make the mold in advance. When the casting process is completed or there is a need to change the shape of the workpiece, the mold is difficult to reuse and causes waste. Summary of the invention

[0009] The purpose of the present invention is to provide a 3D printing molding method for a copper-tin alloy based on a melt infiltration method and a preparation process thereof. The copper-tin alloy prepared by the present invention adopts single copper powder and single tin powder with a particle size of φ10 to 60 μm, and is heated with a mixture of polyoxymethylene (POM), polypropylene (PP), zinc oxide, dioctyl phthalate and dibutyl phthalate to form a mixed material, and a fused deposition type 3D printing process is adopted to prepare a single-substance blank containing a binder and copper-tin. The copper-tin alloy is prepared by a melt infiltration method using a design process. Compared with the traditional preparation of copper-tin alloy, the alloy is prepared by sintering using 3D printing technology combined with a melt infiltration method, and no special casting mold is required, and there is no pollution during the production process.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0011] A copper-tin alloy 3D printing molding method based on the infiltration method comprises the following steps:

[0012] A. mixing metal powder, metal oxide powder and a binder to obtain a mixed powder; the metal powder includes copper powder and tin powder;

[0013] B. heating and kneading the mixed powder to obtain mixed granular material;

[0014] C. injection-molding and extruding the mixed granular material to obtain a plastic filament;

[0015] D. Using the plastic filament to perform 3D printing to obtain a blank;

[0016] E. Degreasing the biscuit to obtain a defatted biscuit;

[0017] F. sintering the degreased green blank at variable temperature to obtain a copper-tin alloy specimen.

[0018] The present invention relates to a method for preparing a copper-tin alloy by a melt infiltration method using a 3D printing molding process. The method uses single copper powder and single tin powder with a particle size of φ10-60μm, and adopts a powder mixing process to prepare a φ1.75mm plastic wire for 3D printing. A single blank containing a binder and copper-tin is manufactured by a 3D printing process, and the copper-tin alloy is manufactured by a melt infiltration method using a design process. The method for preparing a copper-tin alloy by melt infiltration is as follows: (1) adding a certain proportion of polyoxymethylene (POM), polypropylene (PP), zinc oxide, dioctyl phthalate and dibutyl phthalate to 80% by mass of copper and 20% by mass of tin powder, pouring the mixture into a kneader, heating it to 160° C. and kneading it to prepare a uniform mixed granular material; (2) adding the granular material to a screw injection molding machine, and pressurizing and injection molding it into a φ1.75 mm plastic wire; (3) using a 3D printing method to prepare a copper-tin alloy powder blank; (4) using an acid degreasing process to degrease the blank; and (5) sintering the blank to obtain a copper-tin alloy. The copper-tin alloy prepared by the present invention is obtained by using single substance copper and tin through a special sintering process. Compared with the traditional copper-tin alloy preparation process, no alloy powder is needed. Instead, single substance copper and single substance tin powder are mixed with a binder and then sintered into the copper-tin alloy through a melt infiltration method. The ratio between different metal elements can be flexibly adjusted, and no special casting mold is required. There is no pollution in the production process, which is suitable for small-batch and flexible production of complex copper-tin alloy structures.

[0019] The present invention uses a melt infiltration process to prepare 3D printed copper-tin alloy molded parts. The melt infiltration process is to degrease the mixed powder with oxalic acid and then sinter it to form an internally connected copper skeleton; the temperature is heated to a level between liquid tin and solid tin, and the tin (Sn) melts and infiltrates into the pores of the copper (Cu) skeleton, and then the temperature is continued to rise and sinter to form a copper-tin alloy.

[0020] Compared with other alloy preparation methods, the infiltration method usually does not require complex equipment and processes and has lower costs. It uses single metal powders to mix and sinter, and compared with directly using alloy powders, it can flexibly adjust the ratio between different metal elements.

[0021] The present invention uses the melt infiltration method to prepare FDM type 3D printed copper-tin alloy molded parts, expanding the process of flexible small-batch production of small complex metal structures.

[0022] Preferably, in step F, the variable temperature sintering operation includes: a heating rate of 3 to 5°C / min at 25 to 220°C, with an error controlled within ±1.5°C; keeping warm at 225°C for 2 to 5 hours; a heating rate of 0.2 to 0.5°C / min at 225 to 680°C, with an error controlled within ±0.1°C; keeping warm at 680°C for 2 to 6 hours; and then cooling to room temperature to obtain the copper-tin alloy specimen.

[0023] Preferably, in step A, the particle size of the metal powder is 10.0 to 60.0 μm; the particle size of the metal oxide powder is 0.1 to 1.0 μm.

[0024] Preferably, in step A, in the metal powder, the mass ratio of the copper powder to the tin powder is 8:2; in the mixed powder, the mass ratio of the metal powder, the metal oxide powder and the binder is 83-89:0.5-1.5:10.5-15.5.

[0025] Preferably, in step A, the metal oxide powder includes zinc oxide, which functions to compound with the adhesive and metal in the filament, and can significantly improve the wear resistance and rigidity of the 3D printed part; the binder includes one or more of polyoxymethylene, polypropylene, and a plasticizer; the plasticizer includes one or more of dioctyl phthalate and dibutyl phthalate.

[0026] Preferably, the binder includes the polyoxymethylene, the polypropylene, and the plasticizer mixed in a mass ratio of 10-12:0.5-1.5:0.5-1.5; the plasticizer includes the dioctyl phthalate and the dibutyl phthalate mixed in a mass ratio of 0.2-0.4:9.9-10.1.

[0027] Preferably, the average particle size of the single copper and tin powders is 10.0-60.0 μm; the mass ratio of the mixture of dioctyl phthalate and dibutyl phthalate is 0.3:10. The mass fractions of the components are copper, tin powder (86%), polyoxymethylene (POM) 11%, polypropylene (PP) 1%, zinc oxide 1%, dioctyl phthalate (DOP) and dibutyl phthalate (DBP) 1%.

[0028] Preferably, step A also includes: ball milling the metal powder and the metal oxide powder to initially achieve material mixing, and then mixing with the binder to obtain the mixed powder; in step B, the conditions for the banburying include: mixing at a rotation speed of 60 to 70 rpm and a temperature of 170 to 185°C for 6 to 9 hours; in step C, the temperature of the injection extrusion includes 170 to 185°C; in step D, the temperature of the 3D printing includes 190 to 195°C; in step E, the degreasing method includes acid degreasing; in step F, the variable temperature sintering is carried out under a vacuum environment.

[0029] Preferably, in step C, the diameter of the plastic wire is 1.75 mm; in step E, the degreasing agent includes oxalic acid; in step F, the variable temperature sintering is carried out at a vacuum degree of 1 to 2×10 -1 Pa environment.

[0030] Preferably, in step B, the equipment for performing the internal mixing includes a kneader; in step C, the equipment for performing the injection extrusion includes a screw injection molding machine; in step D, the equipment for performing the 3D printing includes an FDM type 3D printer; in step F, the equipment for performing the variable temperature sintering includes a high temperature resistance furnace.

[0031] A copper-tin alloy specimen obtained by a copper-tin alloy 3D printing molding method based on the melt infiltration method.

[0032] The key points of the present invention are "melt infiltration method" and "metal 3D printing"; the invention point is "simplifying the manufacturing difficulty of copper-tin alloy and reducing the waste caused by material loss."

[0033] The present invention uses copper-tin powder and binders such as POM and PP, plasticizers, and toughening agents to knead into printing feed, and then uses an FDM type 3D printer to print out a molded part; then the molded part is placed in an atmosphere furnace, and the melt infiltration principle is used to heat tin (Sn) with a lower melting point to a molten state at a lower temperature and then infiltrate into the pores of the copper (Cu) skeleton, and then the temperature is increased to continue sintering to form a copper-tin alloy.

[0034] The existing casting technology requires that the raw materials be mixed at a relatively high temperature, smelted in a high-temperature furnace, and then cast into a pre-prepared and preheated mold to obtain a copper-tin alloy.

[0035] The existing technology has complicated steps and high costs, which easily leads to waste; however, the present invention skips the step of manufacturing molds, and can manufacture copper-tin alloy parts with various complex structures according to actual needs and can flexibly adjust the proportions of different metal elements.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention uses single copper and tin powders with a particle size of φ10 to 60 μm to sinter into an alloy through a melt infiltration method, without the need for copper-tin alloy powder, making the alloy preparation more convenient;

[0038] The present invention uses polyoxymethylene (POM), polypropylene (PP) and other binders to heat copper and tin powders to make φ1.75mm plastic wires, and uses 3D printing technology to print parts of different shapes. No special casting mold is required, and there is no pollution in the production process.

[0039] The invention controls the sintering process, so that the copper-tin alloy obtained has the characteristics of short alloy formation time, stable and good alloy performance, and effectively prevents segregation.

[0040] The present invention uses the melt infiltration method to prepare FDM type 3D printing copper-tin alloy molded parts, and the obtained copper-tin alloy is obtained by using copper and tin single powders through a special sintering process; compared with the traditional copper-tin alloy preparation process, the present invention does not need alloy powder, but uses single copper and single tin powders mixed with a binder and sintered into copper-tin alloys through the melt infiltration method; the present invention expands the process of small-batch, easy-to-operate, and flexible production of copper-tin alloy molded parts; the manufacturing process does not require the manufacture of molds outside and is controllable throughout the process, and does not cause material waste; compared with other alloy preparation methods such as casting, the present invention reduces many complicated process flows and greatly reduces the operational difficulty of copper-tin alloy production. In addition, the present invention can freely adjust the metal element ratio of different single powders and does not require a special casting mold. There is no pollution in the production process, which is suitable for the flexible production of single-piece small-batch complex metal components. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of the preparation process of the present invention.

[0042] Figure 2 This is a SEM scanning image of the central area of ​​the sample cross section before degreasing.

[0043] Figure 3 This is the SEM scanning image of the central area of ​​the sample cross section after degreasing.

[0044] Figure 4 This is a SEM electron microscope scanning image of the central cross-section of the copper-tin alloy specimen after sintering in a high-temperature resistance furnace.

[0045] Figure 5 for Figure 4 EDS energy spectrum analysis diagram (Sn element). DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] Example 1

[0048] like Figure 1 As shown, a method for manufacturing copper-tin alloy molding by melt infiltration method and its preparation process, the preparation method comprises the following steps:

[0049] (1) Take 80.00g of copper powder with an average particle size of 60μm, 20.00g of tin powder, 1.40g of zinc oxide powder with an average particle size of 0.10μm; 13.45g of polyoxymethylene (POM), 1.20g of polypropylene (PP), 0.08g of dioctyl phthalate (DOP), and 1.30g of dibutyl phthalate (DBP);

[0050] (2) The copper, tin and zinc oxide powders obtained in step (1) were loaded into a zirconia ball mill, with a ball-to-material ratio of 1:7, and the mixture was milled and mixed on a ball mill to prepare a mixture;

[0051] (3) Start the kneading machine and set the kneading machine speed to 60rpm. First add high-melting-point polyoxymethylene, melt it at high temperature and stir it thoroughly, then add low-melting-point polypropylene, dioctyl phthalate, and dibutyl phthalate. Finally, add copper-tin powder and zinc oxide powder. At this time, the temperature is controlled at 170°C for full mixing for 6 hours, and extrude the pellets.

[0052] (4) Pour the pellets obtained in step (2) into the screw injection molding machine, and set the discharge port diameter to φ

[0053] 1.75mm, heated to 185℃, extruded and formed into wire of φ1.75mm;

[0054] (5) Add the filament obtained in step (4) to the FDM 3D printer, set the printing temperature to 190°C, and print the part containing the binder;

[0055] (6) The parts obtained in step (5) were degreased with oxalic acid to remove the binder;

[0056] (7) Place the green billet in a high-temperature resistance furnace and use the following heating process to control sintering: heating rate of 4°C / min at 25-220°C; keep at 225°C for 5h; heating rate of 0.2°C at 225-680°C

[0057] / min; keep at 680℃ for 2h; then cool to room temperature with the furnace. The sintering process adopts vacuum sintering.

[0058] The vacuum degree is 1×10 -1 Pa.

[0059] Example 2

[0060] like Figure 1 As shown, a method for manufacturing copper-tin alloy molding by melt infiltration method and its preparation process, the preparation method comprises the following steps:

[0061] (1) Take 90.00g of copper powder with an average particle size of 10μm, 10.00g of tin powder, 1.50g of zinc oxide powder with an average particle size of 1.0μm; 13.80g of polyoxymethylene (POM), 1.80g of polypropylene (PP), 0.03g of dioctyl phthalate (DOP), and 1.58g of dibutyl phthalate (DBP);

[0062] (2) The copper, tin and zinc oxide powders obtained in step (1) were loaded into a zirconia ball mill, with a ball-to-material ratio of 1:7, and the mixture was milled and mixed on a ball mill to prepare a mixture;

[0063] (3) Start the kneading machine and set the kneading machine speed to 65rpm. First add high-melting point polyoxymethylene, melt it at high temperature and stir it thoroughly, then add low-melting point polypropylene, dioctyl phthalate, dibutyl phthalate, and finally add copper tin powder and zinc oxide powder. At this time, the temperature is controlled at 178℃ and fully mixed for 8 hours, and extruded to make granules;

[0064] (4) Pour the pellets obtained in step (2) into the screw injection molding machine, and set the discharge port diameter to φ

[0065] 1.75mm, heated to 185℃, extruded and formed into wire of φ1.75mm;

[0066] (5) Add the filament obtained in step (4) to the FDM 3D printer and set the printing temperature to 195°C;

[0067] (6) Printing parts containing adhesive;

[0068] (7) The parts obtained in step (5) were degreased with oxalic acid to remove the binder;

[0069] (8) Place the green billet in a high-temperature resistance furnace and use the following heating process to control sintering: heating rate of 3.8℃ / min at 25-220℃; keep at 225℃ for 2h; heating rate of 0.5℃ at 225-680℃

[0070] / min; keep at 680℃ for 2h; then cool to room temperature with the furnace. The sintering process adopts vacuum sintering.

[0071] The vacuum degree is 2×10 -1 Pa.

[0072] Example 3

[0073] like Figure 1 As shown, a method for manufacturing copper-tin alloy molding by melt infiltration method and its preparation process, the preparation method comprises the following steps:

[0074] (1) Take 87.00g of copper powder with an average particle size of 60μm, 13.00g of tin powder, 1.10g of zinc oxide powder with an average particle size of 0.20μm; 14.75g of polyoxymethylene (POM), 1.35g of polypropylene (PP), 0.05g of dioctyl phthalate (DOP), and 1.68g of dibutyl phthalate (DBP);

[0075] (2) The copper, tin and zinc oxide powders obtained in step (1) were loaded into a zirconia ball mill, with a ball-to-material ratio of 1:7, and the mixture was milled and mixed on a ball mill to prepare a mixture;

[0076] (3) Start the kneading machine and set the kneading machine speed to 70 rpm. First add high-melting point polyoxymethylene, melt it at high temperature and stir it thoroughly, then add low-melting point polypropylene, dioctyl phthalate, dibutyl phthalate, and finally add copper tin powder and zinc oxide powder. At this time, the temperature is controlled at 185°C for full mixing for 9 hours, and extrude the pellets;

[0077] (4) Pour the pellets obtained in step (2) into the screw injection molding machine, and set the discharge port diameter to φ

[0078] 1.75mm, heated to 180℃, extruded and formed into wire of φ1.75mm;

[0079] (5) Add the filament obtained in step (4) to the FDM 3D printer, set the printing temperature to 193°C, and print the part containing the binder;

[0080] (6) The parts obtained in step (5) were degreased with oxalic acid to remove the binder;

[0081] (7) Place the green billet in a high-temperature resistance furnace and use the following heating process to control sintering: heating rate of 5°C / min at 25-220°C; keep at 225°C for 4 hours; heating rate of 0.2°C at 225-680°C

[0082] / min; keep at 680℃ for 5h; then cool to room temperature with the furnace. The sintering process adopts vacuum sintering.

[0083] The vacuum degree is 1×10 -1 Pa.

[0084] Example 4

[0085] like Figure 1 As shown, a method for manufacturing copper-tin alloy molding by melt infiltration method and its preparation process, the preparation method comprises the following steps:

[0086] (1) Take 95.00g of copper powder with an average particle size of 30μm, 5.00g of tin powder, 1.44g of zinc oxide powder with an average particle size of 1.0μm; 14.95g of polyoxymethylene (POM), 1.24g of polypropylene (PP), 0.05g of dioctyl phthalate (DOP), and 1.42g of dibutyl phthalate (DBP);

[0087] (2) The copper, tin and zinc oxide powders obtained in step (1) were loaded into a zirconia ball mill, with a ball-to-material ratio of 1:7, and the mixture was milled and mixed on a ball mill to prepare a mixture;

[0088] (3) Start the kneading machine and set the kneading machine speed to 80 rpm. First add high-melting point polyoxymethylene, melt it at high temperature and stir it thoroughly, then add low-melting point polypropylene, dioctyl phthalate, dibutyl phthalate, and finally add copper tin powder and zinc oxide powder. At this time, the temperature is controlled at 170°C for full mixing for 6 hours, and extruded to make pellets;

[0089] (4) Pour the pellets obtained in step (2) into the screw injection molding machine, and set the discharge port diameter to φ

[0090] 1.75mm, heated to 170℃, extruded and formed into wire of φ1.75mm;

[0091] (5) Add the filament obtained in step (4) to the FDM 3D printer, set the printing temperature to 194°C, and print the part containing the binder;

[0092] (6) The parts obtained in step (5) were degreased with oxalic acid to remove the binder;

[0093] The green billet was placed in a high-temperature resistance furnace and sintered using the following heating process: the heating rate was 4.8°C / min at 25-225°C; the temperature was kept at 225°C for 2.5 hours; the heating rate was 0.5°C / min at 225-680°C; the temperature was kept at 680°C for 6 hours; and then the billet was cooled to room temperature. The sintering process was vacuum sintering with a vacuum degree of 2×10 -1 Pa.

[0094] Effect Example 1

[0095] Taking the sample of Example 1 as an example, the test was carried out and the results were as follows: Figures 2 to 5 The test results of other samples are basically similar and are not shown one by one.

[0096] Figure 2 , Figure 3 The SEM scanning images of the center area of ​​the sample cross section before and after degreasing are shown in Figure 2. By comparison, most of the cotton-like adhesive is removed after degreasing, forming a large number of tiny gaps as gas channels, and some skeleton components support the metal powder to keep the shape of the molded blank.

[0097] Figure 4 This is a SEM scanning electron microscope image of the central cross section of a copper-tin alloy specimen sintered in a high-temperature resistance furnace. Combined with X-ray diffraction analysis, it can be seen that the more convex gray dendrite structure is the Cu with a tin-biased phase. 41 Sn 11 , while the more concave structure is the copper-rich phase (Cu, Sn), which indicates that the green billet is fully sintered and basically alloyed.

[0098] Figure 5 for Figure 4 EDS spectrum analysis diagram (Sn element). It can be clearly seen that the overall distribution of Sn elements is uniform, and a large amount of Sn elements are concentrated in the alloy, that is, the white dendritic structure Cu 41 Sn 11 .

[0099] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A 3D printing method for copper-tin alloy based on infiltration method, characterized in that: The following steps are involved: A. mixing metal powder, metal oxide powder and a binder to obtain a mixed powder; the metal powder includes copper powder and tin powder; B. heating and kneading the mixed powder to obtain mixed granular material; C. injection-molding and extruding the mixed granular material to obtain a plastic filament; D. Using the plastic filament to perform 3D printing to obtain a blank; E. Degreasing the biscuit to obtain a defatted biscuit; F. sintering the degreased green blank at variable temperature to obtain a copper-tin alloy specimen.

2. According to claim 1, the copper-tin alloy 3D printing molding method based on the infiltration method is characterized in that: In step F, the variable temperature sintering operation includes: a heating rate of 3 to 5°C / min at 25 to 220°C; keeping warm at 225°C for 2 to 5 hours; a heating rate of 0.2 to 0.5°C / min at 225 to 680°C; keeping warm at 680°C for 2 to 6 hours; and then cooling to room temperature to obtain the copper-tin alloy part.

3. According to claim 1, the copper-tin alloy 3D printing molding method based on the infiltration method is characterized in that: In step A, the particle size of the metal powder is 10.0 to 60.0 μm; the particle size of the metal oxide powder is 0.1 to 1.0 μm.

4. The copper-tin alloy 3D printing molding method based on the infiltration method according to claim 1 is characterized in that: In step A, in the metal powder, the mass ratio of the copper powder to the tin powder includes 8-9.5:0.5-2; in the mixed powder, the mass ratio of the metal powder, the metal oxide powder and the binder includes 83-89:0.5-1.5:10.5-15.

5.

5. The copper-tin alloy 3D printing molding method based on the infiltration method according to claim 1 is characterized in that: In step A, the metal oxide powder includes zinc oxide; the binder includes one or more of polyoxymethylene, polypropylene, and a plasticizer; and the plasticizer includes one or more of dioctyl phthalate and dibutyl phthalate.

6. The copper-tin alloy 3D printing molding method based on the infiltration method according to claim 5 is characterized in that: The binder includes the polyoxymethylene, the polypropylene, and the plasticizer in a mass ratio of 10 to 12: The plasticizer includes the dioctyl phthalate and the dibutyl phthalate mixed in a mass ratio of 0.2-0.4:9.9-10.

1.

7. The copper-tin alloy 3D printing molding method based on the infiltration method according to claim 1 is characterized in that: Step A also includes: ball milling the metal powder and the metal oxide powder, and then mixing them with the binder to obtain the mixed powder; in step B, the conditions of the banburying include: mixing at a rotation speed of 60 to 70 rpm and a temperature of 170 to 185°C for 6 to 9 hours; in step C, the temperature of the injection extrusion includes 170 to 185°C; in step D, the temperature of the 3D printing includes 190 to 195°C; in step E, the degreasing method includes acid degreasing; in step F, the variable temperature sintering is carried out under a vacuum environment.

8. The copper-tin alloy 3D printing molding method based on the infiltration method according to claim 1 is characterized in that: In step C, the diameter of the plastic wire is 1.75 mm; in step E, the degreasing agent is oxalic acid; in step F, the variable temperature sintering is performed at a vacuum degree of 1 to 2×10 -1 Pa environment.

9. The copper-tin alloy 3D printing molding method based on the infiltration method according to claim 1 is characterized in that: In step B, the equipment for performing the internal mixing includes a kneader; in step C, the equipment for performing the injection molding and extrusion includes a screw injection molding machine; in step D, the equipment for performing the 3D printing includes an FDM type 3D printer; in step F, the equipment for performing the variable temperature sintering includes a high temperature resistance furnace.

10. A copper-tin alloy specimen obtained by the copper-tin alloy 3D printing molding method based on the melt infiltration method according to claim 1.

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