A method for preparing tungsten-copper composite material by combining binder jetting 3D printing technology

Abstract

The application discloses a method for preparing a tungsten-copper composite material by combining a binder jetting 3D printing technology, and the method comprises the following steps: (1) adding tungsten-copper mixed powder into a printer hopper, and printing a tungsten-copper green body by a binder jetting 3D printing device; and (2) placing a copper block below the printed tungsten-copper green body, and performing infiltration at 1300-1400 DEG C to obtain the tungsten-copper composite material. The method can prepare a composite material with uniform structure and high density, and the prepared composite material has small shrinkage and high size precision, is particularly suitable for near-net-shape forming of complex shapes, and improves the designability and processability of the tungsten-copper composite material, and expands the application field of the tungsten-copper composite material.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing of metal materials, and specifically to a method for preparing tungsten-copper composite materials using binder jet 3D printing technology. Background Technology

[0002] Tungsten-copper composites combine a range of excellent properties of both tungsten and copper, such as high electrical and thermal conductivity, high hardness, and strong resistance to arc erosion. Due to these superior properties, tungsten-copper composites are widely used in electronic packaging, electrical contacts, and aerospace applications. However, because tungsten and copper are immiscible in both solid and liquid phases, and their densities and melting points differ significantly, tungsten-copper composites cannot be manufactured using traditional smelting methods. To address this issue, tungsten-copper composites are primarily produced using powder metallurgy and melt infiltration methods. However, both methods struggle to fabricate complex, irregularly shaped components. Furthermore, workpieces prepared using these methods require machining to obtain the final product, and the high hardness of tungsten leads to high processing costs. Therefore, developing a new method for manufacturing complex tungsten-copper components is crucial for expanding the application areas of tungsten-copper composites.

[0003] Binder jet 3D printing is an additive manufacturing technology that can form parts at low temperatures. It uses a printhead to selectively eject a binder, bonding powder and powder layers together. After curing, a "green body" is formed, which is then sintered or infiltrated to improve the density and performance of the part. Compared to powder metallurgy and infiltration methods, binder jet 3D printing can rapidly produce components with complex structures, directly forming them without molds, thus significantly improving geometric freedom and production efficiency.

[0004] Because there is no external pressure to compact the powder during the printing process, the green body prepared by binder jet 3D printing has a low density. When the green body is sintered, the low density of the green body leads to large shrinkage and low dimensional accuracy of the sintered sample. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing tungsten-copper composite materials by combining binder jet 3D printing technology. This method utilizes a combination of binder jet 3D printing technology and pressureless melting infiltration technology to prepare tungsten-copper composite materials with complex structures, low shrinkage, high dimensional accuracy, and dense structure, which can be applied to a wider range of fields.

[0006] In one aspect of the invention, a method for preparing tungsten-copper composite materials using binder jetting 3D printing technology is provided. According to an embodiment of the invention, the method includes the following steps:

[0007] (1) Add tungsten copper mixed powder into the printer hopper and print tungsten copper green blanks by spraying binder through the 3D printing equipment.

[0008] (2) Place the copper block under the printed tungsten copper blank and perform melting infiltration to obtain the tungsten copper composite material.

[0009] In addition, a method for preparing tungsten-copper composite materials using binder jet 3D printing technology according to the above embodiments of the present invention may also have the following additional technical features:

[0010] In some embodiments of the present invention, in step (1), the tungsten powder in the tungsten-copper mixed powder is spherical tungsten powder with a particle size of 10-50 μm, and the copper powder is spherical copper powder with a particle size of 10-50 μm. The tungsten powder and copper powder are mixed by a powder mixer for 5-9 hours to obtain the tungsten-copper mixed powder.

[0011] In some embodiments of the present invention, the purity of the spherical tungsten powder and the spherical copper powder is above 99.9%, and the sphericity of the powder is above 98%.

[0012] In some embodiments of the present invention, in step (1), the mass percentage of copper in the tungsten-copper mixed powder is 5%-20%, and the mass percentage of tungsten is 80%-95%.

[0013] In some embodiments of the present invention, in step (1), tungsten copper mixed powder is added to the printer hopper, and the required layer thickness, binder saturation, powder bed temperature and drying time are set according to the particle size of the mixed powder. After printing, the green part is cured in a curing chamber.

[0014] In some embodiments of the present invention, the printing layer thickness is 50-100 μm, the binder saturation is 60%-100%, the metal powder bed temperature is 45-80℃, and the drying time is 7-12s. The binder is a polymer binder, specifically a mixture of polyethylene glycol and stearic acid, with a mass ratio of polyethylene glycol to stearic acid of 8:2. The binder can decompose into gas when kept at 600-700℃ for 1-2 hours.

[0015] In some embodiments of the present invention, the curing time is 4-8 hours, and the curing temperature is 120-180°C.

[0016] In some embodiments of the present invention, in step (2), during melting and infiltration, the temperature is first raised to 600-700°C and held for 1-2 hours, and then raised to 1300-1400°C and held for 2-4 hours. The protective atmosphere is high-purity argon gas, and the argon content of the high-purity argon gas is greater than 99.99%.

[0017] In some embodiments of the present invention, in step (2), the mass percentage of copper in the tungsten-copper composite material is 20%-40%.

[0018] In another aspect of the present invention, the present invention proposes a method for preparing tungsten-copper composite materials according to the aforementioned binder jet 3D printing technology.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] (1) This invention prepares tungsten copper green blanks by using binder jet 3D printing technology, and then uses pressureless melting and infiltration technology to infiltrate copper. During the melting and infiltration process, the copper powder inside the green blank melts and promotes the rearrangement of tungsten particles, while the external copper liquid penetrates into the green blank under the action of capillary force to fill the pores inside the green blank, thus obtaining a composite material with uniform structure and dense structure.

[0021] (2) The present invention adopts a process that combines binder jetting 3D printing technology with pressureless melting and infiltration technology. By filling the pores inside the green blank with external copper liquid during the melting and infiltration process, a tungsten copper composite material with small shrinkage and high dimensional accuracy can be obtained.

[0022] (3) The method described in this invention is simple to operate and has high control precision. It is particularly suitable for near-net-shape forming of complex shapes, which improves the designability and processability of tungsten copper composite materials and expands the application field of tungsten copper composite materials. Attached Figure Description

[0023] Figure 1 In the figures, (a) is the XRD pattern of the tungsten powder used in Examples 2 and 3 of the present invention, (b) is the SEM image of the tungsten powder used in Examples 2 and 3 of the present invention, (c) is the XRD pattern of the copper powder used in Examples 2 and 3 of the present invention, and (d) is the SEM image of the copper powder used in Examples 2 and 3 of the present invention.

[0024] Figure 2 The tungsten copper green blank and tungsten copper composite material prepared in Example 2 of the present invention are shown on the left and on the right. The green blank is a tungsten copper green blank, and the tungsten copper composite material is obtained after the green blank is melt-infiltrated.

[0025] Figure 3 Here is a SEM image of the tungsten-copper composite material prepared in Example 2 of this invention;

[0026] Figure 4 This is a SEM image of the tungsten-copper composite material prepared in Example 3 of the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] A method for preparing tungsten-copper composite materials using binder jetting 3D printing technology, comprising the following specific steps:

[0030] Step 1: Material selection. Select spherical tungsten powder with an average particle size of 35μm and spherical copper powder with an average particle size of 35μm as raw materials. The purity of the spherical tungsten powder and spherical copper powder is above 99.9%, and the sphericity of the powder is above 98%.

[0031] Step 2: Powder mixing. Spherical tungsten powder and spherical copper powder are mixed in a powder mixer for 9 hours to obtain tungsten-copper mixed powder, wherein the mass percentage of copper in the tungsten-copper mixed powder is 5% and the mass percentage of tungsten is 95%.

[0032] Step 3: Printing a tungsten-copper green blank. The tungsten-copper mixed powder is added to the printer hopper. The printing layer thickness is set to 50 μm, binder saturation to 60%, metal powder bed temperature to 60℃, and drying time to 10 s. The binder is a mixture of polyethylene glycol and stearic acid in a mass ratio of 8:2. The green blank is then printed using a binder jetting 3D printing device, resulting in a size of 12×12×3 mm. After printing, the green blank is cured in a curing chamber for 8 hours at 120℃ to remove moisture. The mass of the tungsten-copper green blank is measured to be 4.86 g. Based on the mass divided by the volume, the density of the tungsten-copper green blank is calculated to be 61.71% (theoretical density 18.23 g / cm³). 3 );

[0033] Step 4: Melting and infiltration. Place a 0.92g copper block under the printed tungsten copper green billet and perform melting and infiltration in a tube furnace. The protective atmosphere is high-purity argon with an argon content greater than 99.99%. The melting and infiltration temperature is raised from room temperature to 650℃ and held for 1 hour to decompose polyethylene glycol and stearic acid into gas. Then, the melting and infiltration temperature is raised to 1300℃ and held for 2 hours. After the holding period, the furnace is cooled to room temperature to obtain the W-20Cu composite material.

[0034] The W-20Cu composite material obtained in this embodiment has a density of 96.02% and a thermal conductivity of 201 W·m⁻¹, as tested. -1 ·K -1 It has a hardness of 226HV, a linear shrinkage rate of less than 3%, good shape retention, and high dimensional accuracy.

[0035] Example 2

[0036] A method for preparing tungsten-copper composite materials using binder jetting 3D printing technology, comprising the following specific steps:

[0037] Step 1: Material selection. Select spherical tungsten powder with an average particle size of 35μm and spherical copper powder with an average particle size of 35μm as raw materials. The purity of the spherical tungsten powder and spherical copper powder is above 99.9%, and the sphericity of the powder is above 98%.

[0038] Step 2: Powder mixing. Spherical tungsten powder and spherical copper powder are mixed in a powder mixer for 9 hours to obtain tungsten-copper mixed powder, wherein the mass percentage of copper in the tungsten-copper mixed powder is 10% and the mass percentage of tungsten is 90%.

[0039] Step 3: Printing a tungsten-copper green blank. The tungsten-copper mixed powder is added to the printer hopper. The printing layer thickness is set to 50 μm, binder saturation to 60%, metal powder bed temperature to 60℃, and drying time to 10 s. The binder is a mixture of polyethylene glycol and stearic acid in a mass ratio of 8:2. The green blank, measuring 12×12×3 mm, is then printed using a binder jetting 3D printing device. After printing, the green blank is cured in a curing chamber for 8 hours at 120℃ to remove moisture. The mass of the tungsten-copper green blank is measured to be 4.51 g. Based on the mass divided by the volume, the density of the tungsten-copper green blank is calculated to be 60.41% (theoretical density 17.28 g / cm³). 3 );

[0040] Step 4: Melting and infiltration. Place a 1.29g copper block under the printed tungsten copper green billet and perform melting and infiltration in a tube furnace. The protective atmosphere during melting and infiltration is high-purity argon gas with an argon content greater than 99.99%. The melting and infiltration temperature is raised from room temperature to 650℃ and held for 1 hour to decompose polyethylene glycol and stearic acid into gas. Then, the melting and infiltration temperature is raised to 1300℃ and held for 2 hours. After the holding period, the furnace is cooled to room temperature to obtain the W-30Cu composite material.

[0041] Figure 1 (b) is an SEM image of the tungsten powder used in this embodiment, and (d) is an SEM image of the copper powder used in this embodiment. It can be seen that the tungsten powder and copper powder have high sphericity and wide particle size distribution. During the printing process, small powder particles can fill the gaps between large powder particles, which is beneficial to improving the density of the composite material.

[0042] Figure 2 The images show the tungsten-copper green blank and tungsten-copper composite material prepared in this embodiment. The left side shows the tungsten-copper green blank, and the right side shows the tungsten-copper composite material obtained after pressureless melt infiltration of the green blank. Figure 2It can be seen that, compared with the original size of the green blank, the external copper liquid fills the pores inside the green blank during the pressureless melting process, so that the linear shrinkage of the W-30Cu composite material in the length, width and height directions is within 0.5% after melting, with high shape retention and high dimensional accuracy.

[0043] Figure 3 The image shows an SEM image of the tungsten-copper composite material prepared in this embodiment. As can be seen from the image, the surface of the composite material is dense and there are no obvious pores. Tungsten is uniformly distributed in the copper matrix, which is beneficial for heat transfer and improves the thermal conductivity of the composite material.

[0044] The W-30Cu composite material obtained in this embodiment has a density of 97.72% and a thermal conductivity of 217 W·m⁻². -1 ·K -1 It has a hardness of 208HV, a linear shrinkage rate of less than 0.5%, high density, good shape retention, and high dimensional accuracy.

[0045] Example 3

[0046] A method for preparing tungsten-copper composite materials using binder jetting 3D printing technology, comprising the following specific steps:

[0047] Step 1: Material selection. Select spherical tungsten powder with an average particle size of 35μm and spherical copper powder with an average particle size of 35μm as raw materials. The purity of the spherical tungsten powder and spherical copper powder is above 99.9%, and the sphericity of the powder is above 98%.

[0048] Step 2: Powder mixing. Spherical tungsten powder and spherical copper powder are mixed in a powder mixer for 9 hours to obtain tungsten-copper mixed powder, wherein the mass percentage of copper in the tungsten-copper mixed powder is 20% and the mass percentage of tungsten is 80%.

[0049] Step 3: Printing a tungsten-copper green blank. The tungsten-copper mixed powder is added to the printer hopper. The printing layer thickness is set to 50 μm, binder saturation to 60%, metal powder bed temperature to 60℃, and drying time to 10 s. The binder is a mixture of polyethylene glycol and stearic acid in a mass ratio of 8:2. The green blank, measuring 12×12×3 mm, is then printed using a binder jetting 3D printing device. After printing, the green blank is cured in a curing chamber for 8 hours at 120℃ to remove moisture. The mass of the tungsten-copper green blank is measured to be 4.02 g. Based on the mass divided by the volume, the density of the tungsten-copper green blank is calculated to be 59.30% (theoretical density 15.65 g / cm³). 3 );

[0050] Step 4: Melting and infiltration. Place a 1.34g copper block under the printed tungsten copper green billet and perform melting and infiltration in a tube furnace. The protective atmosphere during melting and infiltration is high-purity argon gas with an argon content greater than 99.99%. The melting and infiltration temperature is raised from room temperature to 650℃ and held for 1 hour to decompose polyethylene glycol and stearic acid into gas. Then, the melting and infiltration temperature is raised to 1300℃ and held for 2 hours. After the holding period, the furnace is cooled to room temperature to obtain the W-40Cu composite material.

[0051] Figure 1 (b) is an SEM image of the tungsten powder used in this embodiment, and (d) is an SEM image of the copper powder used in this embodiment. It can be seen that the tungsten powder and copper powder have high sphericity and wide particle size distribution. During the printing process, small powder particles can fill the gaps between large powder particles, which is beneficial to improving the density of the composite material.

[0052] Figure 4 The image shows an SEM image of the tungsten-copper composite material prepared in this embodiment. As can be seen from the image, the surface of the tungsten-copper composite material is dense and there are no obvious pores. Tungsten is uniformly distributed in the copper matrix, and the copper forms a continuous network structure, which is conducive to heat transfer and improves the thermal conductivity of the composite material.

[0053] The W-40Cu composite material obtained in this embodiment has a density of 98.56% and a thermal conductivity of 229 W·m⁻¹, as tested. -1 ·K -1 It has a hardness of 193HV, a linear shrinkage rate of less than 0.5%, high density, good shape retention, and high dimensional accuracy.

[0054] Example 4

[0055] A method for preparing tungsten-copper composite materials using binder jetting 3D printing technology, comprising the following specific steps:

[0056] Step 1: Material selection. Select spherical tungsten powder with an average particle size of 35μm and spherical copper powder with an average particle size of 35μm as raw materials. The purity of the spherical tungsten powder and spherical copper powder is above 99.9%, and the sphericity of the powder is above 98%.

[0057] Step 2: Powder mixing. Spherical tungsten powder and spherical copper powder are mixed in a powder mixer for 9 hours to obtain tungsten-copper mixed powder, wherein the mass percentage of copper in the tungsten-copper mixed powder is 5% and the mass percentage of tungsten is 95%.

[0058] Step 3: Printing a tungsten-copper green blank. The tungsten-copper mixed powder is added to the printer hopper. The printing layer thickness is set to 50 μm, binder saturation to 60%, metal powder bed temperature to 60℃, and drying time to 10 s. The binder is a mixture of polyethylene glycol and stearic acid in a mass ratio of 8:2. The green blank is then printed using a binder jetting 3D printing device, resulting in a size of 12×12×3 mm. After printing, the green blank is cured in a curing chamber for 8 hours at 120℃ to remove moisture. The mass of the tungsten-copper green blank is measured to be 4.86 g. Based on the mass divided by the volume, the density of the tungsten-copper green blank is calculated to be 61.71% (theoretical density 18.23 g / cm³). 3 );

[0059] Step 4: Melting and infiltration. Place a 0.92g copper block under the printed tungsten copper green billet and perform melting and infiltration in a tube furnace. The protective atmosphere during melting and infiltration is high-purity argon gas with an argon content greater than 99.99%. The melting and infiltration temperature is raised from room temperature to 650℃ and held for 1 hour to decompose polyethylene glycol and stearic acid into gas. Then, the melting and infiltration temperature is raised to 1400℃ and held for 4 hours. After the holding period, the furnace is cooled to room temperature to obtain the W-20Cu composite material.

[0060] The W-20Cu composite material obtained in this embodiment has a density of 97.16% and a thermal conductivity of 205 W·m, according to testing. -1 ·K -1 It has a hardness of 228HV, a linear shrinkage rate of less than 3%, high density, good shape retention, and high dimensional accuracy.

[0061] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the present invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing tungsten-copper composite materials using binder jetting 3D printing technology, characterized in that, Includes the following steps: (1) Add tungsten copper mixed powder into the printer hopper and print tungsten copper blanks through a binder jet 3D printing device. The mass percentage of copper in the tungsten copper mixed powder is 5%-20%, and the mass percentage of tungsten is 80%-95%. (2) Place the copper block under the printed tungsten copper blank and perform melting infiltration to obtain tungsten copper composite material. During melting infiltration, first raise the temperature to 600-700℃ and keep it at that temperature for 1-2 hours, then raise it to 1300-1400℃ and keep it at that temperature for 2-4 hours. The protective atmosphere is high-purity argon gas with an argon content greater than 99.99%.

2. The method for preparing tungsten-copper composite materials using binder jet 3D printing technology according to claim 1, characterized in that: In step (1), the tungsten powder in the tungsten-copper mixed powder is spherical tungsten powder with a particle size of 10-50μm, and the copper powder is spherical copper powder with a particle size of 10-50μm. The tungsten powder and copper powder are mixed for 5-9 hours by a powder mixer to obtain the tungsten-copper mixed powder.

3. The method for preparing tungsten-copper composite materials using binder jet 3D printing technology according to claim 2, characterized in that: The purity of the spherical tungsten powder and spherical copper powder is above 99.9%, and the sphericity of the powder is above 98%.

4. The method for preparing tungsten-copper composite materials using binder jet 3D printing technology according to claim 1, characterized in that: In step (1), tungsten copper mixed powder is added to the printer hopper. The required layer thickness, binder saturation, powder bed temperature and drying time are set according to the particle size of the mixed powder. After printing, the green part is cured in the curing box.

5. The method for preparing tungsten-copper composite materials using binder jetting 3D printing technology according to claim 4, characterized in that: The printing layer thickness is 50-100μm, the binder saturation is 60%-100%, the metal powder bed temperature is 45-80℃, and the drying time is 7-12s. The binder is a polymer binder.

6. The method for preparing tungsten-copper composite materials using binder jetting 3D printing technology according to claim 4, characterized in that: The curing time is 4-8 hours, and the curing temperature is 120-180℃.

7. The method for preparing tungsten-copper composite materials using binder jet 3D printing technology according to claim 1, characterized in that: In step (2), the mass percentage of copper in the tungsten-copper composite material is 20%-40%.

8. A tungsten-copper composite material prepared by a method for preparing tungsten-copper composite materials using a binder jet 3D printing technology according to any one of claims 1-7.

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