Aluminum alloy composite material for 3D printing and preparation method and printing method thereof

Abstract

The invention discloses an aluminum alloy composite material for 3D printing, which comprises the following components in parts by weight: 90-98 parts of aluminum alloy powder, 1-5 parts of aluminum oxide powder, 1-2 parts of copper oxide powder and 1-3 parts of silicon carbide powder, the aluminum alloy powder and the silicon carbide powder are micron-scale powder, and the aluminum oxide powder and the copper oxide powder are nano-scale powder. According to the aluminum alloy composite material for 3D printing, the aluminum oxide powder and the silicon carbide powder are added into the aluminum alloy powder and serve as composite strengthening phases, and the strength and hardness of a printed product are remarkably improved; the copper oxide powder can serve as a plastic phase buffer to counteract stress concentration, brittle fracture caused by a ceramic phase is avoided, and therefore the toughness of the material is improved while the strength and hardness are improved. According to the aluminum alloy composite material for 3D printing disclosed by the invention, the nanoparticles can inhibit aluminum matrix crystal grain growth, refine crystal grains and improve comprehensive mechanical properties, the interface bonding force between the nanoparticles and an aluminum matrix is strong, loads can be effectively transmitted, and stress concentration is avoided.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to an aluminum alloy composite material for 3D printing, its preparation method, and its printing method. Background Technology

[0002] Aluminum alloys possess advantages such as low density, high specific strength, corrosion resistance, and good thermal conductivity, making them widely used in aerospace, automotive, electronics, and many other fields. Binder jet printing, as a crucial process in additive manufacturing, offers advantages such as high production efficiency, relatively low cost, and the ability to manufacture complex structural parts. With the continuous maturation of binder jet printing technology, its application to printing on more materials has been explored, and aluminum alloys, due to their inherent advantages, have become a key research focus. However, aluminum alloy printed products suffer from problems such as low density, poor mechanical properties, easy deformation, and aluminization, as well as issues during sintering such as flammability and oxide buildup on powder surfaces hindering sintering. Effective solutions are needed. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, the present invention provides an aluminum alloy composite material for 3D printing, a preparation method thereof, and a printing method thereof.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A 3D printing aluminum alloy composite material, by weight, comprises 90-98 parts aluminum alloy powder, 1-5 parts alumina powder, 1-2 parts copper oxide powder, and 1-3 parts silicon carbide powder; wherein the aluminum alloy powder and the silicon carbide powder are micron-sized powders, and the alumina powder and the copper oxide powder are nano-sized powders.

[0006] Furthermore, the particle size of the aluminum alloy powder is 0–30 μm; the particle size of the alumina powder is 30–80 nm; the particle size of the copper oxide powder is 30–80 nm; and the particle size of the silicon carbide powder is 3–6 μm.

[0007] Furthermore, the purity of the aluminum alloy powder is greater than 99%; the aluminum alloy, by mass percentage, comprises 1.1% to 2.5% Mg, 0.6% to 1.2% Si, 0.2% to 1.0% Cu, and the remainder, excluding impurity elements, is Al.

[0008] Secondly, the present invention also provides a preparation method for aluminum alloy composite materials for 3D printing as described above, comprising the following steps:

[0009] Pre-dispersion: The alumina powder and the copper oxide powder are pre-dispersed with a dispersant to obtain a nanocomposite suspension.

[0010] Mixing powder: The aluminum alloy powder and the silicon carbide powder are uniformly mixed to obtain a mixed powder;

[0011] Mixing: The nanocomposite suspension is added dropwise to the mixed powder while stirring to obtain a uniformly mixed mixture.

[0012] The mixture is dried, then scattered and sieved to obtain the aluminum alloy composite material for 3D printing.

[0013] Furthermore, the dispersant is an ethanol or silane coupling agent.

[0014] Furthermore, the solid content of the nanocomposite suspension is 5% to 8%.

[0015] Furthermore, in the powder mixing step, the aluminum alloy powder and the silicon carbide powder are mixed by mechanical ball milling, with a ball-to-powder ratio of 10 to 12:1, a ball milling time of 10 to 16 hours, and a ball milling speed of 150 to 250 r / min.

[0016] Furthermore, in the mixing step, the dropping rate of the nanocomposite suspension is 5-10 ml / min, and the mixing time is 20-30 min.

[0017] Furthermore, in the drying step, the mixture is dried using a vacuum drying method at a temperature of 60–120°C for 1–3 hours.

[0018] Thirdly, the present invention also provides a printing method applied to any of the above-described aluminum alloy composite materials for 3D printing, wherein the aluminum alloy composite material binder is used for 3D printing of aluminum alloy products; specifically, the binder jet 3D printing includes the following steps:

[0019] The aluminum alloy composite material is added to the powder spreading device, and the binder is added to the inkjet device. The printing parameters are adjusted according to the established two-dimensional slicing model for printing. After printing, the work box is placed in a vacuum curing box for heat curing, and the powder is cleaned to obtain a green body. The binder is an ether-based low-carbon binder.

[0020] The green body is degreased and sintered; the degreasing temperature is 450℃~550℃, the holding time is 4~8h, the heating rate is 1~5℃ / min, and the degreasing atmosphere is nitrogen; the sintering temperature is 600~680℃, the holding time is 4~10h, and the heating rate is 10~15℃ / min.

[0021] The method of the present invention has the following advantages compared with the prior art:

[0022] This invention discloses an aluminum alloy composite material for 3D printing. Alumina powder and silicon carbide powder are added to aluminum alloy powder, serving as a composite reinforcing phase to significantly improve the strength and hardness of the printed product. Copper oxide powder acts as a plastic phase to buffer and offset stress concentration, preventing brittle fracture caused by the ceramic phase, thereby improving both strength and toughness while enhancing the material's toughness. Furthermore, the nanoparticles in this 3D printing aluminum alloy composite material inhibit grain growth in the aluminum matrix, refine the grains, and improve overall mechanical properties. The strong interfacial bonding between the nanoparticles and the aluminum matrix effectively transfers loads and prevents stress concentration.

[0023] The aluminum alloy composite material for 3D printing disclosed in this invention uses a high-vacuum sintering furnace to prevent oxidation of the aluminum alloy in the binder jet printing process. After sintering, further processing can be used for densification and performance optimization, eliminating porosity, increasing density, optimizing the precipitate distribution of the aluminum alloy matrix, and synergistically enhancing the strengthening effect of nanoparticles. Detailed Implementation

[0024] To facilitate understanding of the present invention, a more complete description will be given below with reference to relevant embodiments. Preferred embodiments of the invention are shown in the embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] One of the objectives of this invention is to disclose an aluminum alloy composite material for 3D printing, comprising, by weight, 90-98 parts aluminum alloy powder, 1-5 parts alumina powder, 1-2 parts copper oxide powder and 1-3 parts silicon carbide powder, wherein the aluminum alloy powder and silicon carbide powder are micron-sized powders, and the alumina powder and copper oxide powder are nano-sized powders.

[0027] Specifically, the particle size of the aluminum alloy powder can be 0–30 μm, and the loose packing density can be greater than or equal to 1.00 g / cm³. 3The powder exhibits good flowability and dispersion, with no agglomeration. The purity of the aluminum alloy powder is greater than 99%. The aluminum alloy composition, by mass percentage, includes 1.1%–2.5% Mg, 0.6%–1.2% Si, and 0.2%–1.0% Cu, with the remainder being Al excluding impurities. The particle size of the alumina powder can be 30–80 nm; the particle size of the copper oxide powder can be 30–80 nm, and the purity of the nano-sized powder is greater than 99.99%. The particle size of the silicon carbide powder can be 3–6 μm. The preferred ratio of alumina powder, silicon carbide powder, and copper oxide powder in the aluminum alloy powder is 5:3:2 or 10:8:5.

[0028] Both alumina and silicon carbide powders are high-hardness ceramic phases, with particle sizes smaller than aluminum alloy powder. When uniformly distributed within the aluminum alloy matrix, they enhance strength and hardness by hindering dislocation movement through dispersion strengthening. When combined, nano-sized alumina fills the gaps between silicon carbide particles, forming a denser reinforcing network with a more significant strengthening effect than a single reinforcing phase. Nano-sized copper oxide powder can be reduced to metallic copper by aluminum during sintering. The resulting copper particles are distributed at grain boundaries or phase interfaces, acting as a ductile phase buffer to offset stress concentration and prevent brittle fracture caused by the ceramic phase, thus improving both strength and toughness while enhancing the material's toughness. Furthermore, during sintering, because copper oxide has a lower melting point than alumina and silicon carbide, it readily forms a liquid phase or a low-melting-point eutectic phase, promoting atomic diffusion, lowering the sintering activation energy, accelerating the densification process, and reducing porosity. Alumina and silicon carbide have good high-temperature stability and can form a rigid framework during sintering, which can inhibit excessive growth of matrix grains. Combined with the liquid-phase sintering effect of copper oxide, they can achieve a synergistic effect of "densification" and "grain refinement", avoiding the grain coarsening problem caused by simple liquid-phase sintering.

[0029] A second objective of this invention is to provide a preparation method applicable to the aluminum alloy composite material described in any of the above embodiments. Specifically, the preparation method may include the following steps:

[0030] S11. Prepare materials by weighing 90-98 parts of aluminum alloy powder, 1-5 parts of alumina powder, 1-2 parts of copper oxide powder and 1-3 parts of silicon carbide powder.

[0031] S12. Pre-dispersion: Alumina powder and copper oxide powder are added to a dispersant and pre-dispersed using ultrasonic vibration for 20–30 minutes to obtain a nanocomposite suspension. The dispersant can be ethanol or a silane coupling agent. The solid content of the dispersed nanocomposite suspension is 5%–8%.

[0032] S13. Powder Mixing: Aluminum alloy powder and silicon carbide powder are uniformly mixed using a mechanical ball milling method to obtain a mixed powder. During the mechanical ball milling process, the ball-to-powder ratio is 10–12:1, the milling time is 10–16 hours, and the milling speed is 150–250 r / min to avoid powder particle breakage caused by high-speed ball milling.

[0033] S14. Mixing: Slowly add the nanocomposite suspension obtained in step S12 to the mixed powder obtained in step S13, stirring continuously while adding, to obtain a uniformly mixed material. The adding rate can be controlled at 5-10 ml / min, and the mixing time can be controlled at 20-30 min.

[0034] S15. The mixture obtained in step S14 is subjected to vacuum drying. During the process, the vacuum degree is maintained below -0.08MPa, the drying temperature is 60-120℃, and the drying time is 1-3h. After drying, the mixture is scattered and sieved to obtain the aluminum alloy composite material for 3D printing of the present invention.

[0035] A third objective of this invention is to provide a printing method that uses the aluminum alloy composite material for 3D printing described in any of the above embodiments to perform binder jet 3D printing of aluminum alloy products. The binder jet 3D printing technology can manufacture aluminum alloy products with complex structures, achieving product lightweighting. Specifically, the manufacturing process may include the following steps:

[0036] S21. Printing: Add the aluminum alloy composite material to the powder spreading device of the printer, and the binder to the inkjet device. Adjust the printing parameters according to the established two-dimensional slicing model and proceed with printing. An ether-based low-carbon-residue binder can be used, with a binder saturation of 40%–60%. Set the printed layer thickness to 30μm–60μm.

[0037] S22. Curing: After printing, the work chamber is placed in a curing chamber for heat curing, and the powder is removed to obtain the green compact. The curing temperature can be 150–300℃, and the curing time can be 1–6 hours. The green compact's properties are tested, including dimensions, surface quality, and strength. The compressive strength of the green compact must be ≥5MPa.

[0038] S23. Degreasing and sintering treatment of the green body. The degreasing temperature is 450℃~550℃, the holding time is 4~8h, the heating rate is 1~5℃ / min, and the degreasing atmosphere is nitrogen. Sintering treatment can be carried out in a high-vacuum sintering furnace with a vacuum degree below 10. -3The sintering temperature was 600–680℃, the holding time was 4–10 h, and the heating rate was 10–15℃ / min. The use of a high-vacuum sintering furnace prevented oxidation of the aluminum alloy. After sintering, further processing can be used for densification and performance optimization. For example, hot isostatic pressing (HIP) can further eliminate porosity and improve density; T6 heat treatment (solution + aging) can optimize the precipitate distribution in the aluminum alloy matrix, synergistically enhancing the strengthening effect of nanoparticles.

[0039] Example 1

[0040] A 3D printing aluminum alloy composite material, by weight, comprises 93.1 parts aluminum alloy powder, 3 parts alumina powder, 1.5 parts copper oxide powder, and 2.4 parts silicon carbide powder. The aluminum alloy powder has a particle size of 0–30 μm and a loose bulk density of 1.074 g / cm³. 3 The aluminum alloy composition includes 1.15% Mg, 0.79% Si, 0.35% Cu, and 97.47% Al. The average particle size of the alumina powder and copper oxide powder is 50 nm, and the average particle size of the silicon carbide powder is 4 μm.

[0041] Furthermore, the particle size of the aluminum alloy powder is: D10: 6-9 μm, D50: 15-18 μm, D90: 22-25 μm.

[0042] The preparation method of aluminum alloy composite material for 3D printing in this embodiment includes the following steps:

[0043] S11, Material preparation: 93.1 parts aluminum alloy powder, 3 parts alumina powder, 1.5 parts copper oxide powder and 2.4 parts silicon carbide powder.

[0044] S12. Pre-dispersion: Alumina powder and copper oxide powder are added to a dispersant and pre-dispersed using ultrasonic vibration for 30 minutes to obtain a nanocomposite suspension. The dispersant is a silane coupling agent. The solid content of the dispersed nanocomposite suspension is 6%.

[0045] S13. Powder Mixing: Aluminum alloy powder and silicon carbide powder are uniformly mixed using a mechanical ball milling method to obtain a mixed powder. During the mechanical ball milling process, the ball-to-powder ratio is 12:1, the milling time is 16 hours, and the milling speed is 250 r / min.

[0046] S14. Mixing: Slowly add the nanocomposite suspension obtained in step S12 to the mixed powder obtained in step S13, stirring continuously while adding, to obtain a uniformly mixed material. The adding rate should be controlled at approximately 9 ml / min, and mixing should continue for 30 minutes.

[0047] S15. The mixture obtained in step S14 is subjected to vacuum drying. During the process, the vacuum degree is maintained below -0.08MPa, the drying temperature is 60-120℃, and the drying time is 1-3h. After drying, the mixture is scattered and sieved to obtain the aluminum alloy composite material for 3D printing in this embodiment.

[0048] This embodiment uses an aluminum alloy composite material for 3D printing to perform binder jet 3D printing of aluminum alloy products. The binder is an ether-based low-carbon binder with a binder saturation of 45% and a printed layer thickness of 30 μm. After printing, a curing treatment is performed at 160℃ for 4 hours. Then, the green body undergoes degreasing and sintering to obtain the aluminum alloy product. The degreasing temperature is 500℃, the holding time is 5 hours, the heating rate is 5℃ / min, and the degreasing atmosphere is nitrogen. The sintering temperature is 650℃, the holding time is 6 hours, and the heating rate is 12℃ / min. It should be noted that a high-vacuum sintering furnace with a vacuum degree of less than 10... -3 Pa.

[0049] The aluminum alloy product obtained in this embodiment has a density of 2.626 g / cm³. 3 It has a density of 97.3%, a hardness of 75HV, a tensile strength of 142MPa, and an elongation after fracture of 5%.

[0050] Example 2

[0051] A 3D printing aluminum alloy composite material, by weight, comprises 96.5 parts aluminum alloy powder, 1.5 parts alumina powder, 1 part copper oxide powder, and 1 part silicon carbide powder. The aluminum alloy powder has a particle size of 0–30 μm; the aluminum alloy composition includes 1.15% Mg, 0.79% Si, 0.35% Cu, and 97.47% Al. The average particle size of the alumina and copper oxide powders is 50 nm, and the average particle size of the silicon carbide powder is 4 μm.

[0052] The preparation method of aluminum alloy composite material for 3D printing in this embodiment includes the following steps:

[0053] S11, Material preparation: 96.5 parts aluminum alloy powder, 1.5 parts alumina powder, 1 part copper oxide powder and 1 part silicon carbide powder.

[0054] S12. Pre-dispersion: Alumina powder and copper oxide powder are added to a dispersant and pre-dispersed using ultrasonic vibration for 30 minutes to obtain a nanocomposite suspension. The dispersant is ethanol. The solid content of the dispersed nanocomposite suspension is 8%.

[0055] S13. Powder Mixing: Aluminum alloy powder and silicon carbide powder are uniformly mixed using a mechanical ball milling method to obtain a mixed powder. During the mechanical ball milling process, the ball-to-powder ratio is 10:1, the milling time is 13 hours, and the milling speed is 150 r / min.

[0056] S14. Mixing: Slowly add the nanocomposite suspension obtained in step S12 to the mixed powder obtained in step S13, stirring continuously while adding, to obtain a uniformly mixed material. The adding rate should be controlled at about 5 ml / min, and mixing should be carried out for 30 minutes.

[0057] S15. The mixture obtained in step S14 is subjected to vacuum drying. During the process, the vacuum degree is maintained below -0.08MPa, the drying temperature is 60-120℃, and the drying time is 1-3h. After drying, the mixture is scattered and sieved to obtain the aluminum alloy composite material for 3D printing in this embodiment.

[0058] This embodiment uses an aluminum alloy composite material for 3D printing to perform binder jet 3D printing of aluminum alloy products. The binder is an ether-based low-carbon binder with a binder saturation of 45% and a printed layer thickness of 30 μm. After printing, a curing treatment is performed at 160℃ for 4 hours. Then, the green body undergoes degreasing and sintering to obtain the aluminum alloy product. The degreasing temperature is 500℃, the holding time is 5 hours, the heating rate is 5℃ / min, and the degreasing atmosphere is nitrogen. The sintering temperature is 650℃, the holding time is 6 hours, and the heating rate is 12℃ / min. It should be noted that a high-vacuum sintering furnace with a vacuum degree of less than 10... -3 Pa.

[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An aluminum alloy composite material for 3D printing, characterized in that, By weight, it includes 90-98 parts aluminum alloy powder, 1-5 parts alumina powder, 1-2 parts copper oxide powder and 1-3 parts silicon carbide powder; The aluminum alloy powder and the silicon carbide powder are micron-sized powders, while the alumina powder and the copper oxide powder are nano-sized powders.

2. The aluminum alloy composite material for 3D printing according to claim 1, characterized in that, The aluminum alloy powder has a particle size of 0–30 μm; the alumina powder has a particle size of 30–80 nm; the copper oxide powder has a particle size of 30–80 nm; and the silicon carbide powder has a particle size of 3–6 μm.

3. The ceramic composite material for 3D printing according to claim 1, characterized in that, The purity of the aluminum alloy powder is greater than 99%; The aluminum alloy, by mass percentage, comprises 1.1% to 2.5% Mg, 0.6% to 1.2% Si, and 0.2% to 1.0% Cu, with the remainder being Al except for impurity elements.

4. A preparation method, applied to the aluminum alloy composite material for 3D printing as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Pre-dispersion: The alumina powder and the copper oxide powder are pre-dispersed with a dispersant to obtain a nanocomposite suspension. Mixing powder: The aluminum alloy powder and the silicon carbide powder are uniformly mixed to obtain a mixed powder; Mixing: The nanocomposite suspension is added dropwise to the mixed powder while stirring to obtain a uniformly mixed mixture. The mixture is dried, then scattered and sieved to obtain the aluminum alloy composite material for 3D printing.

5. The preparation method according to claim 4, characterized in that, The dispersant is an ethanol or silane coupling agent.

6. The preparation method according to claim 5, characterized in that, The solid content of the nanocomposite suspension is 5% to 8%.

7. The preparation method according to claim 4, characterized in that, In the powder mixing step, the aluminum alloy powder and the silicon carbide powder are mixed by mechanical ball milling, with a ball-to-powder ratio of 10 to 12:1, a ball milling time of 10 to 16 hours, and a ball milling speed of 150 to 250 r / min.

8. The preparation method according to claim 4, characterized in that, In the mixing step, the dropping rate of the nanocomposite suspension is 5-10 ml / min, and the mixing time is 20-30 min.

9. The preparation method according to claim 4, characterized in that, In the drying step, the mixture is dried using a vacuum drying method at a temperature of 60–120°C for 1–3 hours.

10. A printing method applied to an aluminum alloy composite material for 3D printing as described in any one of claims 1 to 3, characterized in that, Aluminum alloy products are 3D printed using the aforementioned aluminum alloy composite adhesive jetting. The adhesive jetting 3D printing includes the following steps: The aluminum alloy composite material is added to the powder spreading device, and the binder is added to the inkjet device. The printing parameters are adjusted according to the established two-dimensional slicing model for printing. After printing, the work box is placed in a vacuum curing chamber for heat curing, and the powder is removed to obtain a green body; the binder is an ether-based low-carbon residue binder. The green body is degreased and sintered; the degreasing temperature is 450℃~550℃, the holding time is 4~8h, the heating rate is 1~5℃ / min, and the degreasing atmosphere is nitrogen; the sintering temperature is 600~680℃, the holding time is 4~10h, and the heating rate is 10~15℃ / min.