Method for improving friction performance of 3D printing forming copper-based material

Abstract

The invention provides a method for improving the friction performance of a 3D printing forming copper-based material. The preparation method comprises the steps that (1) the copper-based material and molybdenum disulfide powder are mixed to obtain mixed powder; wherein the molybdenum disulfide powder accounts for 0.5%-5% of the total mass of the copper-based material and the molybdenum disulfide powder, and the particle size of the molybdenum disulfide powder ranges from the micron scale to the nanometer scale; and (2) the mixed powder obtained in the step (1) is subjected to 3D printing forming, and the 3D printing forming copper-based material is obtained after aftertreatment. A proper amount of molybdenum disulfide is doped into the copper-based material, so that the printed and formed copper-based material has excellent friction performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of copper-based materials, and in particular relates to a method for improving the friction performance of 3D printed copper-based materials. Background Art

[0002] With the rapid development of 3D printing technology, 3D printing applications of metal materials have gradually gained widespread attention, especially in the fields of aerospace, automotive, electronics, and machinery. Copper and copper alloys are widely used due to their excellent electrical and thermal conductivity and corrosion resistance. However, copper and copper alloys often perform poorly in friction and wear environments, especially under high temperature or high pressure friction conditions, prone to problems such as rapid wear and severe surface damage. To improve the friction performance of copper and copper alloys, special treatment is usually required on the surface or during the forming process to enhance their wear resistance and anti-friction properties.

[0003] At present, certain research results have been achieved in improving the friction properties of copper alloys through alloying, surface coating or adding friction modifiers. However, most methods are difficult to achieve compatibility with 3D printing technology, and may affect other physical and chemical properties of copper alloys while improving friction performance.

[0004] Therefore, finding a new method that can be implemented in the 3D printing process and effectively improve the friction properties of copper and copper alloys is an urgent problem to be solved. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for improving the friction performance of 3D printed copper-based materials, by adding an appropriate amount of molybdenum disulfide (MoS2) into the copper-based material, so that the printed copper-based material has excellent friction performance.

[0006] The technical solution of the present invention is:

[0007] A first aspect of the present invention provides a method for improving the friction performance of a 3D printed copper-based material, characterized in that the preparation method comprises:

[0008] 1) mixing a copper-based material with molybdenum disulfide powder to obtain a mixed powder; wherein the molybdenum disulfide powder accounts for 0.5% to 5% of the total mass of the mixed powder of the copper-based material and molybdenum disulfide, and the particle size of the molybdenum disulfide powder is in the micrometer to nanometer range;

[0009] 2) The mixed powder obtained in step 1) is subjected to 3D printing and post-processing to obtain a 3D printed copper-based material.

[0010] A second aspect of the present invention provides a 3D printing copper-based material, which is prepared using the method described in the present invention.

[0011] By adopting the above technical solution, the beneficial effects of the present invention are:

[0012] 1. Improve friction performance: Molybdenum disulfide has good self-lubricating properties. As a solid lubricant in copper or copper alloys, it can effectively reduce friction, reduce wear rate, and significantly improve the friction performance of copper and copper alloys, especially under high temperature and high load friction conditions.

[0013] 2. Compatibility with 3D printing technology: The addition of molybdenum disulfide does not affect the 3D printing process of copper and copper alloy powders, demonstrating excellent machinability and compatibility. Therefore, the method of the present invention fully leverages the advantages of 3D printing technology in the production of complex and customized copper alloy structures.

[0014] 3. Environmental friendliness and cost-effectiveness: Molybdenum disulfide is a common and economical lubricating material with good stability and high-temperature resistance. It can effectively improve the friction performance of copper and copper alloys without adding additional environmental burden.

[0015] 4. Improve material life: By optimizing friction performance, the present invention can effectively extend the service life of copper and copper alloys in friction environments and reduce the cost of frequent replacement and maintenance. DETAILED DESCRIPTION

[0016] Hereinafter, an embodiment of a method for improving the friction performance of a 3D printed copper-based material provided by the present invention will be described in detail.

[0017] The "ranges" disclosed herein are defined in terms of lower and upper limits, where a given range is defined by selecting a lower limit and an upper limit, and the selected lower and upper limits define the boundaries of the particular range. Ranges defined in this manner can be inclusive or exclusive of the end values ​​and can be combined arbitrarily, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise indicated, the numerical range "a to b" is a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0018] After extensive research, the inventors of the present invention found that traditional copper alloys have insufficient performance in friction and wear scenarios, and it is difficult to balance conductivity and self-lubrication. After adding molybdenum disulfide, the friction coefficient of the composite material can be reduced while maintaining high conductivity, solving the need for dynamic components such as bearings and brushes to synergistically optimize the dual functions of "conductivity-lubrication". In addition, the layered structure of molybdenum disulfide forms a dispersion strengthening effect in the copper matrix, which can increase the hardness of the material, achieve "strength-conductivity" synergistic optimization, and meet the needs of precision components. On this basis, this application was completed.

[0019] [Methods to improve the friction performance of 3D printed copper-based materials]

[0020] The present invention provides a method for improving the friction performance of a 3D printed copper-based material. The preparation method comprises:

[0021] 1) mixing a copper-based material with molybdenum disulfide powder to obtain a mixed powder; wherein the molybdenum disulfide powder accounts for 0.5% to 5% of the total mass of the copper-based material and the molybdenum disulfide powder, and the particle size of the molybdenum disulfide powder is in the micrometer to nanometer range;

[0022] 2) The mixed powder obtained in step 1) is subjected to 3D printing and post-processing to obtain a 3D printed copper-based material.

[0023] In the method for improving the friction performance of 3D printing copper-based materials provided by the present invention, step 1) is to mix the copper-based material with molybdenum disulfide powder to obtain a mixed powder. Specifically,

[0024] In step 1) of the present invention, the copper-based material is selected from one or more of pure copper, copper-aluminum alloy, copper-nickel alloy, and the like. The copper-based material is in the form of a powder. Optionally, the particle size of the copper-based material can be, for example, 15 to 45 μm, more preferably 15 to 30 μm, 30 to 45 μm, or the like.

[0025] In step 1) of the present invention, the mixing is selected from one of mechanical mixing, ball milling or ultrasonic treatment to ensure the uniformity of dispersion of molybdenum disulfide in the copper powder or copper alloy powder.

[0026] In some embodiments, the mechanical mixing speed is 200-300 rpm, optionally, the speed can be, for example, 200-250 rpm or 250-300 rpm, etc. The mixing time is 1-3 h, optionally, the mixing time can be, for example, 1-2 h or 2-3 h, etc.

[0027] In some embodiments, the ball milling ratio is 1-3:1-1, optionally, the ball milling ratio is 1-2:1-1 or 2-3:1-1. The ball milling time is 1-3 hours, optionally, the ball milling time can be, for example, 1-2 hours or 2-3 hours.

[0028] In some embodiments, the ultrasonic treatment frequency is 40 kHz to 60 kHz. Alternatively, the ultrasonic treatment frequency can be, for example, 40 kHz to 50 kHz or 50 kHz to 60 kHz. The treatment time is 0.5 to 2 hours. Alternatively, the treatment time can be, for example, 0.5 to 1 hour or 1 to 2 hours.

[0029] In step 1) of the present invention, the molybdenum disulfide powder accounts for 0.5% to 5% of the total mass of the copper-based material and the molybdenum disulfide powder. Alternatively, for example, the molybdenum disulfide powder accounts for 0.5% to 1%, 1% to 3%, or 3% to 5% of the total mass of the copper-based material and the molybdenum disulfide powder. Preferably, the molybdenum disulfide powder accounts for 1% to 3% of the total mass of the copper-based material and the molybdenum disulfide powder. Within this range, the advantages are balanced energy absorption and heat conduction, and optimal forming density. A concentration greater than 5% has the disadvantage of easily forming agglomerates on the powder surface, resulting in reduced powder flowability. A concentration less than 0.5% has the disadvantage of good powder flowability, but may lead to unfused defects due to insufficient light absorption.

[0030] In step 1) of the present invention, the particle size of the molybdenum disulfide powder is 0.5-5 μm. Alternatively, the particle size of the molybdenum disulfide powder can be, for example, 0.5-3 μm, 3-5 μm, 0.5-2 μm, 2-4 μm, or 4-5 μm. Within this range, the advantages are good powder dispersibility and relatively stable interfacial bonding. Outside this range, the disadvantages are that too small particle size easily agglomerates, forming stress concentration points, and is prone to work hardening during ball milling.

[0031] In the method for improving the friction performance of 3D printed copper-based materials provided by the present invention, step 2) is to 3D print the mixed powder obtained in step 1), and then perform post-processing to obtain the 3D printed copper-based material. Specifically:

[0032] In step 2) of the present invention, 3D printing adopts one or more of selective laser melting and electron beam melting; 3D printing forming is to subject the mixed powder to laser scanning or electron beam heating to melt it and form it layer by layer.

[0033] Optionally, during selective laser melting, the laser power is 330-370 W. Optionally, the laser power can be, for example, 330-350 W or 350-370 W. The scanning speed is 400-600 mm / s. Optionally, the scanning speed can be, for example, 400-500 mm / s or 500-600 mm / s. The scanning pitch is 0.08-0.12 mm. Optionally, the scanning pitch can be, for example, 0.08-0.10 mm or 0.10-0.12 mm. The layer thickness is 20-30 μm. Optionally, the layer thickness can be, for example, 20-25 μm or 25-30 μm. The protective atmosphere is argon. Within the aforementioned selective laser melting range, the advantages are a stable molten pool, high density, and excellent performance. Disadvantages outside the range are defects such as weak interlayer bonding or excessive energy input leading to spatter.

[0034] Optionally, in electron beam melting, the electron beam power is 1.5 to 3 kW. Optionally, the electron beam power can be, for example, 1.5 to 2 kW or 2 to 3 kW. The electron flow current is 10 to 15 mA. Optionally, the electron flow current can be, for example, 10 to 12 mA or 12 to 15 mA. The layer thickness is 50 to 80 μm. Optionally, the layer thickness can be, for example, 50 to 60 μm, 60 to 70 μm or 70 to 80 μm. The scanning spacing is 60 to 100 μm. Optionally, the scanning spacing is 60 to 80 μm or 80 to 100 μm. Within the aforementioned range of electron beam melting conditions, the advantage is that it can balance melt penetration and heat input, ensuring high density and excellent performance. The disadvantage outside the range is excessive unfused defects or the generation of adverse effects such as spattering and spheroidization.

[0035] In step 2) of the present invention, post-treatment includes heat treatment and / or mechanical processing to further improve the density and surface quality of the material and improve its friction performance. In some embodiments, the temperature of the heat treatment is 400-600°C. Alternatively, the temperature of the heat treatment can be, for example, 400-500°C or 500-600°C. The time of the heat treatment is 1-2 hours. Alternatively, the time of the heat treatment can be, for example, 1-1.5 hours or 1.5-2 hours. The mechanical processing is polishing or fine grinding of the formed part, and the surface roughness is Ra0.8-Ra0.05. Alternatively, the surface roughness can be, for example, Ra0.8-Ra0.4, Ra0.4-Ra0.05, Ra0.8-Ra0.6, Ra0.6-Ra0.4, Ra0.4-Ra0.2, Ra0.2-Ra0.05, etc. Within the aforementioned range, the advantage is that the strength can be improved and various properties can be balanced. The disadvantage outside the range is that the strengthening effect is lost and the performance drops sharply.

[0036] 【3D printing copper-based materials】

[0037] The present invention also provides a 3D printing formed copper-based material, which is obtained by using the method for improving the friction performance of the 3D printing formed copper-based material as described in the present invention.

[0038] The beneficial effects of the present invention are:

[0039] 1. Improve friction performance: Molybdenum disulfide has good self-lubricating properties. As a solid lubricant in copper or copper alloys, it can effectively reduce friction, reduce wear rate, and significantly improve the friction performance of copper and copper alloys, especially under high temperature and high load friction conditions.

[0040] 2. Compatibility with 3D printing technology: The addition of molybdenum disulfide does not affect the 3D printing process of copper and copper alloy powders, demonstrating excellent machinability and compatibility. Therefore, the method of the present invention fully leverages the advantages of 3D printing technology in the production of complex and customized copper alloy structures.

[0041] 3. Environmental friendliness and cost-effectiveness: Molybdenum disulfide is a common and economical lubricating material with good stability and high-temperature resistance. It can effectively improve the friction performance of copper and copper alloys without adding additional environmental burden.

[0042] 4. Improve material life: By optimizing friction performance, the present invention can effectively extend the service life of copper and copper alloys in friction environments and reduce the cost of frequent replacement and maintenance.

[0043] The beneficial effects of the present invention are further illustrated below with reference to the examples.

[0044] In order to make the invention objectives, technical solutions and beneficial technical effects of the present invention clearer, the present invention is further described in detail below with reference to the examples. However, it should be understood that the examples of the present invention are only for the purpose of explaining the present invention and are not intended to limit the present invention, and the examples of the present invention are not limited to the examples given in the specification. In the examples, where no specific experimental conditions or operating conditions are specified, the products were prepared under conventional conditions or under the conditions recommended by the material supplier.

[0045] Furthermore, it should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before or after the combination step, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the presence of other devices / apparatuses before or after the combination device / apparatus, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the present invention.

[0046] In the following examples, unless otherwise specified, various raw materials of the present invention can be purchased commercially or prepared according to conventional methods in the art.

[0047] Friction coefficient test method: Use a pin-on-disc friction and wear tester, and the conditions are:

[0048] Grinding material: Steel ball (6mm diameter)

[0049] Load: 50N, speed: 200rpm, test time: 30min

[0050] Environment: room temperature, humidity 40% to 60%

[0051] Take the average value during the stable phase.

[0052] Wear rate test method: The mass loss of the sample before and after wear (high-precision balance) is combined with the wear distance to calculate the volume wear rate. Refer to ASTM G99-17 "Standard Test Method for Wear Testing"

[0053] Surface finish test method: stylus surface roughness measuring instrument, conditions are:

[0054] The measurement length is 4mm, the cut-off wavelength is 0.8mm, and the average value of 3 measurements is taken.

[0055] According to GB / T 1031-2009 "Surface roughness parameters and their values", test the Ra value.

[0056] Example 1

[0057] 1. Prepare pure copper powder and molybdenum disulfide powder, wherein the particle size of the pure copper powder is 30 μm, the particle size of the molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 1% of the total mass of the pure copper powder and the molybdenum disulfide powder;

[0058] 2. Use a ball mill (ball milling ratio of 1:1) for 1 hour to mix the pure copper powder and molybdenum disulfide powder evenly;

[0059] 3. The mixed powder was 3D printed using selective laser melting (SLM) technology, with a laser power of 350 W, a scanning speed of 400 mm / s, a scanning interval of 0.10 mm, a layer thickness of 30 μm, and an argon protective atmosphere to print a disc sample with a diameter of 10 mm.

[0060] 4. Heat treat the printed samples (450°C, hold for 2 hours) and then perform wear tests.

[0061] The results show that the friction coefficient of the copper alloy sample doped with molybdenum disulfide in Example 1 is 0.10, and the wear rate is 4×10 -4 mm 3 N -1 m -1 , surface finish Ra0.2. Compared with pure copper samples, the friction coefficient is reduced by about 30% and the wear volume is reduced by 40%.

[0062] Example 2

[0063] 1. Prepare copper-aluminum alloy powder and molybdenum disulfide powder, wherein the particle size of pure copper powder is 30 μm, the particle size of molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 2% of the total mass of pure copper powder and molybdenum disulfide powder;

[0064] 2. Use ultrasonic treatment (frequency of 40 kHz, treatment time of 1 hour) to evenly disperse the molybdenum disulfide powder in the copper-aluminum alloy powder;

[0065] 3. Electron beam melting (EBM) technology is used for 3D printing, where the electron beam power is 1.5kW, the current is 15mA, the layer thickness is 50μm, and the scanning pitch is 80μm. Complex geometric structural components are printed; the component has a three-dimensional structure with integrated spiral cooling channels inside; the exterior is surrounded by a honeycomb grid, and the pores and struts are interwoven in a curved surface, which combines connectivity and macrostructural strength.

[0066] 4. Wear test of printed parts showed that the friction coefficient of the parts was 0.07 and the wear rate was 2×10 -4 mm 3 N -1 m -1 , surface finish Ra0.2. The wear resistance under friction conditions is significantly improved, and the surface finish and service life are effectively improved.

[0067] Example 3

[0068] 1. Prepare pure copper powder and molybdenum disulfide powder, wherein the particle size of the pure copper powder is 30 μm, the particle size of the molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 0.5% of the total mass of the pure copper powder and the molybdenum disulfide powder;

[0069] 2. Use a ball mill (ball milling ratio of 1:1) for 1 hour to mix the pure copper powder and molybdenum disulfide powder evenly;

[0070] 3. The mixed powder was 3D printed using selective laser melting (SLM) technology with a laser power of 350 W, a scanning speed of 400 mm / s, a scanning interval of 0.10 mm, a layer thickness of 30 μm, and an argon protective atmosphere to produce a disc sample with a diameter of 10 mm.

[0071] 4. Heat treat the printed samples (450°C, hold for 2 hours) and then perform wear tests.

[0072] The results show that the friction coefficient of the copper alloy sample doped with molybdenum disulfide in Example 3 is 0.11, and the wear rate is 6×10 -4 mm 3 N -1 m -1 , surface finish Ra0.2.

[0073] Example 4

[0074] 1. Prepare pure copper powder and molybdenum disulfide powder, wherein the particle size of the pure copper powder is 30 μm, the particle size of the molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 3% of the total mass of the pure copper powder and the molybdenum disulfide powder;

[0075] 2. Use a ball mill (ball milling ratio of 1:1) for 1 hour to mix the pure copper powder and molybdenum disulfide powder evenly;

[0076] 3. The mixed powder was 3D printed using selective laser melting (SLM) technology with a laser power of 350 W, a scanning speed of 400 mm / s, a scanning interval of 0.10 mm, a layer thickness of 30 μm, and an argon protective atmosphere to produce a disc sample with a diameter of 10 mm.

[0077] 4. Heat treat the printed samples (450°C, hold for 2 hours) and then perform wear tests.

[0078] The results show that the friction coefficient of the copper alloy sample doped with molybdenum disulfide in Example 4 is 0.09, and the wear rate is 3×10 -4 mm 3 N -1 m -1 , surface finish Ra0.2.

[0079] Example 5

[0080] 1. Prepare pure copper powder and molybdenum disulfide powder, wherein the particle size of the pure copper powder is 30 μm, the particle size of the molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 5% of the total mass of the pure copper powder and the molybdenum disulfide powder;

[0081] 2. Use a ball mill (ball milling ratio of 1:1) for 1 hour to mix the pure copper powder and molybdenum disulfide powder evenly;

[0082] 3. The mixed powder was 3D printed using selective laser melting (SLM) technology with a laser power of 350 W, a scanning speed of 400 mm / s, a scanning interval of 0.10 mm, a layer thickness of 30 μm, and an argon protective atmosphere to produce a disc sample with a diameter of 10 mm.

[0083] 4. Heat treat the printed samples (450°C, hold for 2 hours) and then perform wear tests.

[0084] The results show that the friction coefficient of the copper alloy sample doped with molybdenum disulfide in Example 3 is 0.12, and the wear rate is 9×10 -4 mm 3 N -1 m -1 , surface finish Ra0.2.

[0085] Example 6

[0086] 1. Prepare pure copper powder and molybdenum disulfide powder, wherein the particle size of the pure copper powder is 30 μm, the particle size of the molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 3% of the total mass of the pure copper powder and the molybdenum disulfide powder;

[0087] 2. Use a ball mill (ball milling ratio of 3:1) for 1 hour to mix the pure copper powder and molybdenum disulfide powder evenly;

[0088] 3. The mixed powder was 3D printed using selective laser melting (SLM) technology with a laser power of 350 W, a scanning speed of 400 mm / s, a scanning interval of 0.10 mm, a layer thickness of 30 μm, and an argon protective atmosphere to produce a disc sample with a diameter of 10 mm.

[0089] 4. Heat treat the printed samples (450°C, hold for 2 hours) and then perform wear tests.

[0090] The results show that the friction coefficient of the copper alloy sample doped with molybdenum disulfide in Example 6 is 0.08, and the wear rate is 2.6×10 -4 mm 3 N -1 m-1 , surface finish Ra0.2.

[0091] Example 7

[0092] 1. Prepare pure copper powder and molybdenum disulfide powder, wherein the particle size of the pure copper powder is 30 μm, the particle size of the molybdenum disulfide powder is 1 μm, and the molybdenum disulfide powder accounts for 3% of the total mass of the pure copper powder and the molybdenum disulfide powder;

[0093] 2. Use a ball mill (ball milling ratio of 3:1) for 1 hour to mix the pure copper powder and molybdenum disulfide powder evenly;

[0094] 3. The mixed powder was 3D printed using selective laser melting (SLM) technology with a laser power of 370 W, a scanning speed of 450 mm / s, a scanning interval of 0.10 mm, a layer thickness of 30 μm, and an argon protective atmosphere to produce a disc sample with a diameter of 10 mm.

[0095] 4. Heat treat the printed samples (450°C, hold for 2 hours) and then perform wear tests.

[0096] The results show that the friction coefficient of the copper alloy sample doped with molybdenum disulfide in Example 3 is 0.07, and the wear rate is 2.2×10 -4 mm 3 N -1 m -1 , surface finish Ra0.2.

[0097] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0098] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for improving the friction performance of 3D printed copper-based materials, characterized in that: The preparation method comprises: 1) mixing a copper-based material with molybdenum disulfide powder to obtain a mixed powder; wherein the molybdenum disulfide powder accounts for 0.5% to 5% of the total mass of the mixed powder of the copper-based material and molybdenum disulfide, and the particle size of the molybdenum disulfide powder is in the micrometer to nanometer range; 2) The mixed powder obtained in step 1) is subjected to 3D printing and post-processing to obtain a 3D printed copper-based material.

2. The method for improving the friction performance of 3D printed copper-based materials according to claim 1, characterized in that: In step 1), the copper-based material is selected from one or more of pure copper, copper-aluminum alloy, and copper-nickel alloy.

3. The method for improving the friction performance of 3D printed copper-based materials according to claim 1, characterized in that: In step 1), the mixing is one of mechanical mixing, ball milling or ultrasonic treatment.

4. The method for improving the friction performance of 3D printed copper-based materials according to claim 3, characterized in that: In step 1), any one or more of the following conditions may also be included: A1) the mechanical mixing speed is 200-300 rpm, and the mixing time is 1-3 hours; A2) the ball milling ratio is 1-3:1-1; the ball milling time is 1-3 hours; A3) The frequency of the ultrasonic treatment is 40 kHz to 60 kHz, and the treatment time is 0.5 to 2 hours.

5. The method for improving the friction performance of 3D printed copper-based materials according to claim 1, characterized in that: In step 1), any one or more of the following conditions may also be included: B1) the molybdenum disulfide powder is 1% to 3% of the total mass of the copper-based material and the molybdenum disulfide powder; B2) the particle size of the molybdenum disulfide powder is 0.5 to 5 μm; B3) The particle size of the copper-based material is 15 to 45 μm.

6. The method for improving the friction performance of 3D printed copper-based materials according to claim 1, characterized in that: In step 2), 3D printing uses one or more of selective laser melting and electron beam melting; 3D printing forming is to subject the mixed powder to laser scanning or electron beam heating to melt it and form it layer by layer.

7. The method for improving the friction performance of 3D printed copper-based materials according to claim 6, characterized in that: In step 2), any one or more of the following conditions may also be included: C1) In selective laser melting, the laser power is 330-370 W, the scanning speed is 400-600 mm / s, the scanning pitch is 0.08-0.12 mm, the layer thickness is 20-30 μm, and the protective atmosphere is argon; C2) In electron beam melting, the electron beam power is 1.5 to 3 kW, the electron current is 10 to 15 mA, the layer thickness is 50 to 80 μm, and the scanning interval is 60 to 100 μm.

8. The method for improving the friction performance of 3D printed copper-based materials according to claim 1, characterized in that: In step 2), post-processing includes heat treatment and / or mechanical processing.

9. The method for improving the friction performance of 3D printed copper-based materials according to claim 8, characterized in that: In step 2), any one or more of the following conditions may also be included: D1) the temperature of the heat treatment is 400-600° C.; D2) the heat treatment time is 1 to 2 hours; D3) The machining is polishing or fine grinding of the formed part, with the surface roughness being Ra0.8 to Ra0.

05.

10. A 3D printing copper-based material prepared by the method according to any one of claims 1 to 9.