NANO-LANTHANUM OXIDE REINFORCED TUNGSTEN-BASED COMPOSITE MATERIAL AND PREPARATION METHOD THEREOF

Abstract

The present disclosure discloses a nano-lanthanum oxide reinforced tungsten-based composite material and a preparation method thereof. A pure tungsten powder and a nano-lanthanum oxide powder are mixed to obtain a mixed powder, and in the mixed powder, the nano-lanthanum oxide powder accounts for 0.5-2% of the mixed powder by mass percent; and then, 3D printing forming is conducted on the mixed powder to obtain a bulk material of the nano-lanthanum oxide reinforced tungsten-based composite material. The nano-lanthanum oxide reinforced tungsten-based composite material of the present disclosure has excellent mechanical properties.

Claims

1. A nano-lanthanum oxide reinforced tungsten-based composite material, wherein, a pure tungsten powder and a nano-lanthanum oxide powder are mixed to obtain a mixed powder, and in the mixed powder, the nano-lanthanum oxide powder accounts for 0.5-2% of the mixed powder by mass percent; and then, 3D printing is conducted on the mixed powder to obtain the nano-lanthanum oxide reinforced tungsten-based composite material.

2. The nano-lanthanum oxide reinforced tungsten-based composite material according to claim 1, wherein, the pure tungsten powder has a particle size of 5-25 μm.

3. The nano-lanthanum oxide reinforced tungsten-based composite material according to claim 1, wherein, the nano-lanthanum oxide powder has a particle size of 50-100 nm.

4. A preparation method of a nano-lanthanum oxide reinforced tungsten-based composite material, comprising: step 1: weighing and mixing a pure tungsten powder and a nano-lanthanum oxide powder to obtain a mixed powder, wherein, the pure tungsten powder accounts for 98-99.5% of the mixed powder by mass percent, and the nano-lanthanum oxide powder accounts for 0.5-2% of the mixed powder by mass percent; step 2: fully mixing the mixed powder in an argon atmosphere to obtain a fully mixed powder; and step 3: conducting 3D printing by using the fully mixed powder obtained in step 2 as a 3D printing material to obtain the nano-lanthanum oxide reinforced tungsten-based composite material.

5. The preparation method according to claim 4, wherein, in step 1, the pure tungsten powder has a particle size of 5-25 μm.

6. The preparation method according to claim 4, wherein, in step 1, the nano-lanthanum oxide powder has a particle size of 50-100 nm.

7. The preparation method according to claim 4, wherein, in step 2, the step of fully mixing the mixed powder in an argon atmosphere to obtain a fully mixed powder comprises: putting the mixed powder into a ball mill, introducing argon into the ball mill for protection, conducting mixing for 1.5-3.5 h without milling balls to obtain a fully mixed powder, and sealing and storing the fully mixed powder in a vacuum environment.

8. The preparation method according to claim 7, wherein, in step 2, the ball mill has a motor rotation speed of 900-1,100 r/min, air cooling is conducted for 10 min after mixing is conducted for 30 min, and the mixing is repeated 4 times for a total of 2 h.

9. The preparation method according to claim 4, wherein, in step 3, conducting 3D printing by using the fully mixed powder obtained in step 2 as a 3D printing material to obtain the nano-lanthanum oxide reinforced tungsten-based composite material comprises: constructing a three-dimensional model by using CAD software in a computer, and conducting slice layering and path planning of an energy source; and based on the slice layering and the path planning of an energy source, conducting 3D printing in an argon environment by using the fully mixed powder obtained in step 2 as a 3D printing material to obtain the nano-lanthanum oxide reinforced tungsten-based composite material.

10. The preparation method according to claim 9, wherein, in step 3, based on the slice layering and the path planning of an energy source, conducting 3D printing in an argon environment by using the fully mixed powder obtained in step 2 as a 3D printing material to obtain the nano-lanthanum oxide reinforced tungsten-based composite material comprises: setting a layer thickness to 25 μm, putting a stainless steel substrate in a forming cavity, putting the fully mixed powder obtained by mixing in step 2 in a powder cylinder, and introducing argon into the closed forming cavity; and based on the slice layering and the path planning of an energy source, conducting processing layer by layer according to preset process parameters to obtain the nano-lanthanum oxide reinforced tungsten-based composite material, wherein, the preset process parameters comprise a set laser power of 250-350 W, a scanning speed of 200-400 mm/s and a scanning spacing of 90-150 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a diagram showing internal defects of a W-0.5% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in Example 1 of the present disclosure and observed with an optical microscope;

[0030] FIG. 2 is a diagram showing microscopic structures of the W-0.5% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in Example 1 of the present disclosure and observed with an optical microscope;

[0031] FIG. 3 is a diagram showing internal defects of a W-1% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in Example 2 of the present disclosure and observed with an optical microscope;

[0032] FIG. 4 is a diagram showing microscopic structures of the W-1% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in Example 2 of the present disclosure and observed with an optical microscope;

[0033] FIG. 5 is a diagram showing internal defects of a W-2% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in Example 3 of the present disclosure and observed with an optical microscope;

[0034] FIG. 6 is a diagram showing microscopic structures of the W-2% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in Example 3 of the present disclosure and observed with an optical microscope;

[0035] FIG. 7 is a diagram showing internal defects of a pure tungsten sample obtained by laser 3D printing in a comparative example of the present disclosure and observed with an optical microscope;

[0036] FIG. 8 is a diagram showing microscopic structures of the pure tungsten sample obtained by laser 3D printing in the comparative example of the present disclosure and observed with an optical microscope;

[0037] FIG. 9 is a comparison diagram showing microhardness tests of the samples prepared in Example 1, Example 2, Example 3 and the comparative example; and

[0038] FIG. 10 is a comparison diagram showing compression curves of the samples prepared in Example 1, Example 2, Example 3 and the comparative example.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] Some examples listed below are intended only to better illustrate the present disclosure, but contents of the present disclosure are not limited to application of the listed examples. Therefore, nonessential modifications and adjustments of embodiments made by those skilled in the art based on the above contents of the present disclosure still fall within the protection scope of the present disclosure when applied to other examples.

[0040] It should be noted that experimental methods without specific conditions in the following examples should be used in accordance with conventional conditions or conditions suggested by manufacturers.

Example 1

[0041] In this example, a preparation method of a lanthanum oxide reinforced tungsten-based composite material was provided. The method included the following steps:

[0042] step 1: a pure tungsten powder (with a particle size of 5-25 μm) and a nano-lanthanum oxide powder (with a particle size of 50-100 nm) were weighed and mixed to obtain a mixed powder, where, the pure tungsten powder accounted for 99.5% of the mixed powder by mass percent, and the nano-lanthanum oxide powder accounted for 0.5% of the mixed powder by mass percent;

[0043] step 2: the mixed powder was put into a ball mill for full mixing for 2 h to obtain a W-0.5% La.sub.2O.sub.3 powder, and the powder was sealed and stored in a vacuum environment, where, argon was introduced into the ball mill for protection to prevent oxidation of the powder during the mixing, and milling balls were not added during the mixing to protect the sphericity of the tungsten powder;

[0044] step 3: a three-dimensional model was conducted by using CAD software in a computer, and slice layering and planning of a laser path were conducted by using 3D printing slicing software; a layer thickness was set to 25 μm; a stainless steel substrate was put in a forming cavity, the powder obtained by mixing in step 2 was put in a powder cylinder, and argon was introduced into the closed forming cavity; processing was conducted layer by layer according to process parameters set in software, where, a set laser power was 300 W, a laser scanning speed was 200 mm/s, and a laser scanning spacing was 150 μm; and processing was conducted until a set layer number was achieved to obtain a sample; and

[0045] step 4: the sample obtained by laser 3D printing was ground and polished, observed with an optical microscope to obtain internal defects, etched with an etching agent and then observed with an optical microscope to obtain microscopic structures.

[0046] FIG. 1 was a diagram showing the internal defects of the W-0.5% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that the sample had few internal defects including only few short and narrow cracks and a small amount of pores.

[0047] FIG. 2 was a diagram showing the microscopic structures of the W-0.5% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that whole tungsten grains had relatively small size and relatively uniform size distribution.

Example 2

[0048] In this example, a 3D printing preparation method of a lanthanum oxide reinforced tungsten-based composite material was provided. The method included the following steps:

[0049] step 1: a pure tungsten powder (with a particle size of 5-25 μm) and a nano-lanthanum oxide powder (with a particle size of 50-100 nm) were weighed and mixed to obtain a mixed powder, where, the pure tungsten powder accounted for 99% of the mixed powder by mass percent, and the nano-lanthanum oxide powder accounted for 1% of the mixed powder by mass percent;

[0050] step 2: the mixed powder was put into a ball mill for full mixing for 2 h to obtain a W-1% La.sub.2O.sub.3 powder, and the powder was sealed and stored in a vacuum environment, where, argon was introduced into the ball mill for protection to prevent oxidation of the powder during the mixing, and milling balls were not added during the mixing to protect the sphericity of the tungsten powder;

[0051] step 3: a three-dimensional model was conducted by using CAD software in a computer, and slice layering and planning of a laser path were conducted by using 3D printing slicing software; a layer thickness was set to 25 μm; a stainless steel substrate was put in a forming cavity, the powder obtained by mixing in step 2 was put in a powder cylinder, and argon was introduced into the closed forming cavity; processing was conducted layer by layer according to process parameters set in software, where, a set laser power was 300 W, a laser scanning speed was 200 mm/s, and a laser scanning spacing was 150 μm; and processing was conducted until a set layer number was achieved to obtain a sample; and

[0052] step 4: the sample obtained by laser 3D printing was ground and polished, observed with an optical microscope to obtain internal defects, etched with an etching agent and then observed with an optical microscope to obtain microscopic structures.

[0053] FIG. 3 was a diagram showing the internal defects of the W-1% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that the sample had few internal defects including only few short and narrow cracks and a small amount of pores.

[0054] FIG. 4 was a diagram showing the microscopic structures of the W-1% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that whole tungsten grains had relatively small size and relatively uniform size distribution.

Example 3

[0055] In this example, a laser 3D printing preparation method of a lanthanum oxide reinforced tungsten-based composite material was provided. The method included the following steps:

[0056] step 1: a pure tungsten powder (with a particle size of 5-25 μm) and a nano-lanthanum oxide powder (with a particle size of 50-100 nm) were weighed and mixed to obtain a mixed powder, where, the pure tungsten powder accounted for 98% of the mixed powder by mass percent, and the nano-lanthanum oxide powder accounted for 2% of the mixed powder by mass percent;

[0057] step 2: the mixed powder was put into a ball mill for full mixing for 2 h to obtain a W-2% La.sub.2O.sub.3 powder, and the powder was sealed and stored in a vacuum environment, where, argon was introduced into the ball mill for protection to prevent oxidation of the powder during the mixing, and milling balls were not added during the mixing to protect the sphericity of the tungsten powder;

[0058] step 3: a three-dimensional model was conducted by using CAD software in a computer, and slice layering and planning of a laser path were conducted by using 3D printing slicing software; a layer thickness was set to 25 μm; a stainless steel substrate was put in a forming cavity, the powder obtained by mixing in step 2 was put in a powder cylinder, and argon was introduced into the closed forming cavity; processing was conducted layer by layer according to process parameters set in software, where, a set laser power was 300 W, a laser scanning speed was 200 mm/s, and a laser scanning spacing was 150 μm; and processing was conducted until a set layer number was achieved to obtain a sample; and

[0059] step 4: the sample obtained by laser 3D printing was ground and polished, observed with an optical microscope to obtain internal defects, etched with an etching agent and then observed with an optical microscope to obtain microscopic structures.

[0060] FIG. 5 was a diagram showing the internal defects of the W-2% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that the sample had few internal defects including only few short and narrow cracks and a small amount of pores.

[0061] FIG. 6 was a diagram showing the microscopic structures of the W-2% La.sub.2O.sub.3 composite material sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that whole tungsten grains had relatively small size and relatively uniform size distribution.

Comparative Example

[0062] In this example, a laser 3D printing preparation method of pure tungsten was provided. The method included the following steps:

[0063] a three-dimensional model was conducted by using CAD software in a computer, and slice layering and planning of a laser path were conducted by using 3D printing slicing software; a layer thickness was set to 25 μm; a stainless steel substrate was put in a forming cavity, a pure tungsten powder (with a particle size of 5-25 μm) was put in a powder cylinder, and argon was introduced into the closed forming cavity; processing was conducted layer by layer according to process parameters set in software, where, a set laser power was 300 W, a laser scanning speed was 200 mm/s, and a laser scanning spacing was 150 μm; and processing was conducted until a set layer number was achieved to obtain a sample; and

[0064] step 4: the sample obtained by laser 3D printing was ground and polished, observed with an optical microscope to obtain internal defects, etched with an etching agent and then observed with an optical microscope to obtain microscopic structures.

[0065] FIG. 7 was a diagram showing the internal defects of the pure tungsten sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that the sample had many internal defects including a large number of long and wide cracks and large pores.

[0066] FIG. 8 was a diagram showing the microscopic structures of the pure tungsten sample obtained by laser 3D printing in this example and observed with an optical microscope. It could be seen that whole tungsten grains had relatively large size and nonuniform size distribution.

[0067] FIG. 9 was a comparison diagram showing microhardness tests of the samples prepared in Example 1, Example 2, Example 3 and the comparative example. It could be seen that the sample of the present disclosure had higher microhardness.

[0068] FIG. 10 was a comparison diagram showing compression curves of the samples prepared in Example 1, Example 2, Example 3 and the comparative example. It could be seen that the sample of the present disclosure had higher compressive strength.

[0069] By combining the examples above, a sample with fewer defects, fine and uniform microscopic structures and better mechanical properties is obtained by laser 3D printing in the present disclosure.

[0070] The examples of the present disclosure are described above with reference to the accompanying drawings, and a lanthanum oxide doped tungsten printed part with significantly reduced cracks is obtained. From the examples above, it can be seen that different final results are achieved when different materials are used in a production process. Better effects of the tungsten-based printed part may be achieved by those of ordinary skill in the art by improving the relevant process parameters and using different materials under the inspiration of the present disclosure, and all these effects fall within the protection scope of the present disclosure.