A powder metallurgy material and its application

Abstract

The invention provides a powder metallurgy material and its application, relates to the technical field of metallurgical materials, and is made of the following components by weight percentage: graphene 3wt%-6wt%, nano zirconium diboride 0.5wt%-1.5wt%, copper powder 6wt%-10wt%, manganese powder 0.8wt%-1.2wt%, nano tungsten carbide 0.3wt%-0.6wt%, lubricant 0wt%-1wt%, rare earth 0.01wt-0.05wt%, niobium powder 0.1wt%-0.3wt%, hafnium powder 0.03wt%-0.05wt%, rhenium powder 0.001wt%-0.003wt%, chromium powder 3wt%-5wt%, and the balance is iron powder. The powder metallurgy material has good mechanical properties, good wear resistance, corrosion resistance and heat resistance, and long service life.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical materials, and in particular to a powder metallurgical material and application thereof. Background Art

[0002] Powder metallurgy is a process that uses metal powder (or a mixture of metal powder and non-metal powder) as raw materials to form and sinter metal materials, composite materials and various types of products. Powder metallurgy technology has a series of advantages such as significant energy saving, material saving, excellent performance, high product precision and good stability. It is very suitable for mass production and has been widely used in transportation, machinery, nuclear industry and other fields, becoming one of the most dynamic branches in new materials science.

[0003] Traditional powder metallurgy materials have technical problems such as high cost, poor tensile strength, certain restrictions on the size and shape of products, and poor toughness of sintered parts. Existing ordinary powder metallurgy materials also have more or less defects such as the inability to improve tensile strength and elongation at the same time, insufficient friction performance, and the need to further improve heat resistance and corrosion resistance.

[0004] In order to solve the above problems, the Chinese invention patent with the authorization publication number CN104388740B discloses a copper-based graphite and zirconium powder metallurgy composite material and its preparation method. The composite material is composed of the following weight percentages of materials: graphite 5%-12%, zirconium 0.5%-1%, titanium 0.8%-1.5%, chromium 2%-3%, lead 1%-3%, zinc 5%-8%, tin 4%-6%, and the balance is copper. Preparation method: a. Mix the materials evenly according to their weight percentage; b. Sinter at 600-900℃ for 8-10 hours under nitrogen protection. The invention prepares copper-based graphite and zirconium powder metallurgy composite materials to refine the alloy grains, hinder the expansion of cracks in the alloy, and improve the performance of the alloy. The inventive material has good tensile properties and can meet various requirements in practical applications. However, its performance stability, wear resistance, heat resistance and corrosion resistance still need to be further improved.

[0005] It can be seen that the development of a powder metallurgy material with good mechanical properties, good wear resistance, corrosion resistance and heat resistance, and long service life meets market demand, has broad market value and application prospects, and plays a vital role in promoting the further development of powder metallurgy technology. Summary of the invention

[0006] In view of the above problems, the object of the present invention is to provide a powder metallurgy material with good mechanical properties, good wear resistance, corrosion resistance and heat resistance, and long service life, and its application.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is: a powder metallurgy material is made of the following components in weight percentage: 3wt%-6wt% of graphene, 0.5wt%-1.5wt% of nano zirconium diboride, 6wt%-10wt% of copper powder, 0.8wt%-1.2wt% of manganese powder, 0.3wt%-0.6wt% of nano tungsten carbide, 0wt%-1wt% of lubricant, 0.01wt%-0.05wt% of rare earth, 0.1wt%-0.3wt% of niobium powder, 0.03wt%-0.05wt% of hafnium powder, 0.001wt%-0.003wt% of rhenium powder, 3wt%-5wt% of chromium powder, and the balance is iron powder.

[0008] Preferably, the powder metallurgy material further comprises: 0.01wt%-0.03wt% of a binder, 0.1wt%-0.2wt% of bicyclo[2.2.1]heptanedimethylamine, and 0.05wt%-0.15wt% of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group.

[0009] Preferably, the graphene is a single-layer graphene with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the particle size of the nano zirconium diboride is 30-80 nm; and the particle size of the nano tungsten carbide is 20-60 nm.

[0010] Preferably, the particle size of the copper powder is 800-1200 mesh; the particle size of the manganese powder is 1000-1300 mesh; the particle size of the rare earth is 500-800 mesh; the particle size of the niobium powder is 800-1000 mesh; the particle size of the hafnium powder is 600-1000 mesh; the particle size of the rhenium powder is 900-1300 mesh; the particle size of the chromium powder is 800-1000 mesh; and the particle size of the iron powder is 1000-1400 mesh.

[0011] Preferably, the lubricant is zinc stearate.

[0012] Preferably, the rare earth is at least one of lanthanum and cerium.

[0013] Preferably, the binder is a mixture of sodium silicate and sodium tripolyphosphate in a mass ratio of (3-5):1.

[0014] Preferably, there is no special requirement for the source of the polyethersulfone type hyperbranched epoxy resin with epoxy terminal groups. In one embodiment of the present invention, the polyethersulfone type hyperbranched epoxy resin with epoxy terminal groups is prepared according to the method of implementation case 18 in the authorization publication number CN104311832B.

[0015] Another object of the present invention is to provide a method for preparing the powder metallurgy material, comprising the following steps:

[0016] Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly;

[0017] Step S2: putting the mixed raw materials into a mold, pressing to obtain a compact, and then sintering in a vacuum atmosphere or under nitrogen protection.

[0018] Step S3: After heat treatment, a powder metallurgy material is obtained.

[0019] Preferably, the heat treatment in step S3 includes quenching and tempering treatment; the quenching temperature is 1000-1100°C, the holding time is 1-2 hours, and oil cooling to room temperature; the tempering temperature is 650-700°C, and the tempering treatment time is 1-2 hours.

[0020] Preferably, the sintering in step S2 is hot pressing sintering, the sintering temperature is 1250-1300° C., the holding time is 1-2 h, and the pressure applied to the mold is 10-20 MPa.

[0021] Preferably, the pressing pressure in step S2 is 300-500 MPa.

[0022] Another object of the present invention is to provide an application of the powder metallurgy material in the preparation of automobile bearings.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The preparation method of the powder metallurgy material disclosed in the present invention has simple process, convenient operation, high preparation efficiency and finished product qualification rate, low dependence on equipment, suitable for continuous large-scale production, and has high promotion and application value.

[0025] (2) The powder metallurgy material disclosed in the present invention is made of the following components in percentage by weight: 3wt%-6wt% of graphene, 0.5wt%-1.5wt% of nano zirconium diboride, 6wt%-10wt% of copper powder, 0.8wt%-1.2wt% of manganese powder, 0.3wt%-0.6wt% of nano tungsten carbide, 0wt%-1wt% of lubricant, 0.01wt%-0.05wt% of rare earth, 0.1wt%-0.3wt% of niobium powder, 0.03wt%-0.05wt% of hafnium powder, 0.001wt%-0.003wt% of rhenium powder, 3wt%-5wt% of chromium powder, and the balance is iron powder; through the mutual cooperation between the components, a suitable grain size and grain shape can be obtained, and at the same time, the material densification degree is improved, and the strength and toughness are improved, so that the manufactured material has good mechanical properties, good wear resistance, corrosion resistance and heat resistance, and a long service life.

[0026] (3) The powder metallurgy material disclosed in the present invention, with the added graphene, nano zirconium diboride, and nano tungsten carbide, cooperates with each other to refine the alloy grains and hinder the expansion of cracks in the alloy, thereby effectively improving the wear resistance and mechanical properties of the material, making it suitable for manufacturing bearings, extending the service life, and reducing wear.

[0027] (4) The powder metallurgy material disclosed in the present invention further comprises: 0.01wt%-0.03wt% of a binder, 0.1wt%-0.2wt% of bicyclo[2.2.1]heptanedimethylamine, and 0.05wt%-0.15wt% of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group. The addition of the above components and their coordination can improve the compatibility between the components, thereby improving the comprehensive performance and performance stability of the material. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the product of the present invention is further described in detail below in conjunction with embodiments.

[0029] Example 1

[0030] A powder metallurgy material is made of the following components in percentage by weight: 3wt% of graphene, 0.5wt% of nano zirconium diboride, 6wt% of copper powder, 0.8wt% of manganese powder, 0.3wt% of nano tungsten carbide, 0.1wt% of lubricant, 0.01wt% of rare earth, 0.1wt% of niobium powder, 0.03wt% of hafnium powder, 0.001wt% of rhenium powder, 3wt% of chromium powder, and the balance is iron powder.

[0031] The powder metallurgy material further comprises: 0.01 wt% of a binder, 0.1 wt% of bicyclo[2.2.1]heptanedimethylamine, and 0.05 wt% of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group.

[0032] The graphene is a single-layer graphene with a sheet diameter of 0.5 μm and a thickness of 0.8 nm; the particle size of the nano zirconium diboride is 30 nm; the particle size of the nano tungsten carbide is 20 nm; the particle size of the copper powder is 800 mesh; the particle size of the manganese powder is 1000 mesh; the particle size of the rare earth is 500 mesh; the particle size of the niobium powder is 800 mesh; the particle size of the hafnium powder is 600 mesh; the particle size of the rhenium powder is 900 mesh; the particle size of the chromium powder is 800 mesh; and the particle size of the iron powder is 1000 mesh.

[0033] The lubricant is zinc stearate; the rare earth is lanthanum; the binder is a mixture of sodium silicate and sodium tripolyphosphate in a mass ratio of 3:1; the polyethersulfone type hyperbranched epoxy resin with epoxy end groups is prepared according to the method of implementation case 18 in the authorization publication number CN104311832B.

[0034] A method for preparing the powder metallurgy material comprises the following steps:

[0035] Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly;

[0036] Step S2, loading the mixed raw materials into a mold, pressing to obtain a compact, and then sintering in a vacuum atmosphere; the sintering is hot pressing sintering, the sintering temperature is 1250° C., the holding time is 1 hour, the pressure applied to the mold is 10 MPa; the pressing pressure is 300 MPa;

[0037] Step S3, after heat treatment, a powder metallurgy material is obtained; the heat treatment includes quenching and tempering treatment; the quenching temperature is 1000°C, the holding time is 1 hour, and oil cooling to room temperature; the tempering temperature is 650°C, and the tempering treatment time is 1 hour.

[0038] An application of the powder metallurgy material in preparing automobile bearings.

[0039] Example 2

[0040] A powder metallurgy material is made of the following components in percentage by weight: 4wt% of graphene, 0.7wt% of nano zirconium diboride, 7wt% of copper powder, 0.9wt% of manganese powder, 0.4wt% of nano tungsten carbide, 0.2wt% of lubricant, 0.02wt% of rare earth, 0.15wt% of niobium powder, 0.035wt% of hafnium powder, 0.0015wt% of rhenium powder, 3.5wt% of chromium powder, and the balance is iron powder.

[0041] The powder metallurgy material further comprises: 0.015 wt % of a binder, 0.12 wt % of bicyclo[2.2.1]heptanedimethylamine, and 0.08 wt % of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group.

[0042] The graphene is a single-layer graphene with a sheet diameter of 1.5 μm and a thickness of 0.9 nm; the particle size of the nano zirconium diboride is 40 nm; the particle size of the nano tungsten carbide is 30 nm; the particle size of the copper powder is 900 mesh; the particle size of the manganese powder is 1100 mesh; the particle size of the rare earth is 600 mesh; the particle size of the niobium powder is 900 mesh; the particle size of the hafnium powder is 700 mesh; the particle size of the rhenium powder is 1000 mesh; the particle size of the chromium powder is 900 mesh; and the particle size of the iron powder is 1100 mesh.

[0043] The lubricant is zinc stearate; the rare earth is cerium; the binder is a mixture of sodium silicate and sodium tripolyphosphate in a mass ratio of 3.5:1; the polyethersulfone type hyperbranched epoxy resin with epoxy end groups is made according to the method of implementation case 18 in the authorization publication number CN104311832B.

[0044] A method for preparing the powder metallurgy material comprises the following steps:

[0045] Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly;

[0046] Step S2, loading the mixed raw materials into a mold, pressing to obtain a compact, and then sintering under nitrogen protection; the sintering is hot pressing sintering, the sintering temperature is 1260° C., the holding time is 1.2 h, the pressure applied to the mold is 13 MPa; the pressing pressure is 350 MPa;

[0047] Step S3, after heat treatment, a powder metallurgy material is obtained; the heat treatment includes quenching and tempering treatment; the quenching temperature is 1030°C, the holding time is 1.2 hours, and oil cooling to room temperature; the tempering temperature is 670°C, and the tempering treatment time is 1.2 hours.

[0048] An application of the powder metallurgy material in preparing automobile bearings.

[0049] Example 3

[0050] A powder metallurgy material is made of the following components in percentage by weight: 4.5wt% of graphene, 1wt% of nano zirconium diboride, 8wt% of copper powder, 1wt% of manganese powder, 0.45wt% of nano tungsten carbide, 0.5wt% of lubricant, 0.035wt% of rare earth, 0.2wt% of niobium powder, 0.04wt% of hafnium powder, 0.002wt% of rhenium powder, 4wt% of chromium powder, and the balance is iron powder.

[0051] The powder metallurgy material further comprises: 0.02 wt % of a binder, 0.15 wt % of bicyclo[2.2.1]heptanedimethylamine, and 0.1 wt % of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group.

[0052] The graphene is a single-layer graphene with a sheet diameter of 3.5 μm and a thickness of 1 nm; the particle size of the nano zirconium diboride is 60 nm; the particle size of the nano tungsten carbide is 40 nm; the particle size of the copper powder is 1000 mesh; the particle size of the manganese powder is 1150 mesh; the particle size of the rare earth is 650 mesh; the particle size of the niobium powder is 900 mesh; the particle size of the hafnium powder is 850 mesh; the particle size of the rhenium powder is 11500 mesh; the particle size of the chromium powder is 900 mesh; and the particle size of the iron powder is 1200 mesh.

[0053] The lubricant is zinc stearate; the rare earth is lanthanum; the binder is a mixture of sodium silicate and sodium tripolyphosphate in a mass ratio of 4:1; the polyethersulfone type hyperbranched epoxy resin with epoxy end groups is prepared according to the method of implementation case 18 in the authorization publication number CN104311832B.

[0054] A method for preparing the powder metallurgy material comprises the following steps:

[0055] Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly;

[0056] Step S2, loading the mixed raw materials into a mold, pressing to obtain a green compact, and then sintering in a vacuum atmosphere; the sintering is hot pressing sintering, the sintering temperature is 1280° C., the holding time is 1.5 h, the pressure applied to the mold is 15 MPa; the pressing pressure is 400 MPa;

[0057] Step S3, after heat treatment, a powder metallurgy material is obtained; the heat treatment includes quenching and tempering treatment; the quenching temperature is 1060°C, the holding time is 1.5 hours, and oil cooling to room temperature; the tempering temperature is 680°C, and the tempering treatment time is 1.5 hours.

[0058] An application of the powder metallurgy material in preparing automobile bearings.

[0059] Example 4

[0060] A powder metallurgy material is made of the following components in percentage by weight: 5.5wt% of graphene, 1.3wt% of nano zirconium diboride, 9.5wt% of copper powder, 1.1wt% of manganese powder, 0.55wt% of nano tungsten carbide, 0.9wt% of lubricant, 0.04wt% of rare earth, 0.1wt%-0.3wt% of niobium powder, 0.03wt%-0.05wt% of hafnium powder, 0.001wt%-0.003wt% of rhenium powder, 3wt%-5wt% of chromium powder, and the balance is iron powder.

[0061] The powder metallurgy material further comprises: 0.025 wt% of a binder, 0.18 wt% of bicyclo[2.2.1]heptanedimethylamine, and 0.14 wt% of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group.

[0062] The graphene is a single-layer graphene with a sheet diameter of 4.5 μm and a thickness of 1.1 nm; the particle size of the nano zirconium diboride is 70 nm; the particle size of the nano tungsten carbide is 50 nm; the particle size of the copper powder is 1100 mesh; the particle size of the manganese powder is 1250 mesh; the particle size of the rare earth is 750 mesh; the particle size of the niobium powder is 950 mesh; the particle size of the hafnium powder is 950 mesh; the particle size of the rhenium powder is 1200 mesh; the particle size of the chromium powder is 950 mesh; and the particle size of the iron powder is 1350 mesh.

[0063] The lubricant is zinc stearate; the rare earth is lanthanum and cerium mixed in a mass ratio of 3:5; the binder is a mixture of sodium silicate and sodium tripolyphosphate mixed in a mass ratio of 4.5:1; the polyethersulfone type hyperbranched epoxy resin with epoxy end groups is made according to the method of implementation case 18 in the authorization publication number CN104311832B.

[0064] A method for preparing the powder metallurgy material comprises the following steps:

[0065] Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly;

[0066] Step S2, loading the mixed raw materials into a mold, pressing to obtain a compact, and then sintering under nitrogen protection; the sintering is hot pressing sintering, the sintering temperature is 1290° C., the holding time is 1.9 h, the pressure applied to the mold is 19 MPa; the pressing pressure is 450 MPa;

[0067] Step S3, after heat treatment, a powder metallurgy material is obtained; the heat treatment includes quenching and tempering treatment; the quenching temperature is 1090°C, the holding time is 1.8 hours, and oil cooling to room temperature; the tempering temperature is 690°C, and the tempering treatment time is 1.8 hours.

[0068] An application of the powder metallurgy material in preparing automobile bearings.

[0069] Example 5

[0070] A powder metallurgy material is made of the following components in percentage by weight: 6wt% of graphene, 1.5wt% of nano zirconium diboride, 10wt% of copper powder, 1.2wt% of manganese powder, 0.6wt% of nano tungsten carbide, 1wt% of lubricant, 0.05wt% of rare earth, 0.3wt% of niobium powder, 0.05wt% of hafnium powder, 0.003wt% of rhenium powder, 5wt% of chromium powder, and the balance is iron powder.

[0071] The powder metallurgy material further comprises: 0.03 wt % of a binder, 0.2 wt % of bicyclo[2.2.1]heptanedimethylamine, and 0.15 wt % of a polyethersulfone type hyperbranched epoxy resin having an epoxy end group.

[0072] The graphene is a single-layer graphene with a sheet diameter of 5 μm and a thickness of 1.2 nm; the particle size of the nano zirconium diboride is 80 nm; the particle size of the nano tungsten carbide is 60 nm; the particle size of the copper powder is 1200 mesh; the particle size of the manganese powder is 1300 mesh; the particle size of the rare earth is 800 mesh; the particle size of the niobium powder is 1000 mesh; the particle size of the hafnium powder is 1000 mesh; the particle size of the rhenium powder is 1300 mesh; the particle size of the chromium powder is 1000 mesh; and the particle size of the iron powder is 1400 mesh.

[0073] The lubricant is zinc stearate; the rare earth is cerium; the binder is a mixture of sodium silicate and sodium tripolyphosphate in a mass ratio of 5:1; the polyethersulfone type hyperbranched epoxy resin with epoxy end groups is made according to the method of implementation case 18 in the authorization publication number CN104311832B.

[0074] A method for preparing the powder metallurgy material comprises the following steps:

[0075] Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly;

[0076] Step S2, loading the mixed raw materials into a mold, pressing to obtain a green compact, and then sintering in a vacuum atmosphere; the sintering is hot pressing sintering, the sintering temperature is 1300° C., the holding time is 2 h, the pressure applied to the mold is 20 MPa; the pressing pressure is 500 MPa;

[0077] Step S3, after heat treatment, a powder metallurgy material is obtained; the heat treatment includes quenching and tempering treatment; the quenching temperature is 1100°C, the holding time is 2 hours, and oil cooling to room temperature; the tempering temperature is 700°C, and the tempering treatment time is 2 hours.

[0078] An application of the powder metallurgy material in preparing automobile bearings.

[0079] Comparative Example 1

[0080] A powder metallurgy material is substantially the same as that of Example 1, except that nano zirconium diboride and rhenium powder are not added.

[0081] Comparative Example 2

[0082] A powder metallurgy material is substantially the same as that of Example 1, except that nano-tungsten carbide and rare earth are not added.

[0083] In order to further illustrate the unexpected positive technical effects achieved by the products of each embodiment of the present invention, the powder metallurgy materials prepared in each example were subjected to relevant performance tests. The test results are shown in Table 1. The test method is as follows:

[0084] (1) Wear resistance: A WTM-2E friction and wear tester was used, GCr15 ball bearing steel was used as the friction pair, the load was 100g, the friction diameter was 8mm, the rotation speed was 200r / min, and the time was 20min; before the experiment, the oxide scale on the surface to be ground was removed to expose the flat surface of the sample, the disc was rotated horizontally, and the sample was in vertical contact with the disc through the upper fixture, and the two rubbed and wore each other. The wear time was 20min to ensure that a stable wear state was achieved; the mass loss was measured using a Sartius Micro electronic balance, and the weight change of the sample during the wear process was studied, and the weight loss rate was calculated to measure the wear resistance of the material. The smaller the weight loss rate, the better the wear resistance.

[0085] (2) Hardness: The reference test standard is GBT 9097.1-2002 "Determination of apparent hardness of sintered metal materials (excluding cemented carbide) Part 1: Materials with basically uniform cross-sectional hardness". Test 6 points and calculate the average value.

[0086] (3) Tensile strength: Tested in accordance with standard GB / T228-2002 “Room temperature tensile test method for metal materials”.

[0087] (4) Corrosion resistance: The prepared powder metallurgy materials were subjected to a salt spray corrosion test at a test temperature of 35°C. A 5% mass concentration sodium chloride aqueous solution was sprayed in the test chamber to simulate the accelerated corrosion environment. The powder metallurgy materials were qualified for corrosion resistance if their tolerance time (i.e., the time they remained rust-free) exceeded 500 hours; otherwise, they were unqualified.

[0088] Table 1

[0089] project Weight loss rate (%) Hardness(HRB) Tensile strength(MPa) Corrosion resistance Example 1 0.32 68.5 1200 qualified Example 2 0.28 69.1 1211 qualified Example 3 0.25 69.9 1226 qualified Example 4 0.20 71.0 1235 qualified Example 5 0.18 72.2 1248 qualified Comparative Example 1 0.54 65.4 1054 qualified Comparative Example 2 0.46 62.7 1085 qualified

[0090] It can be seen from Table 1 that the powder metallurgy material disclosed in the embodiment of the present invention has better wear resistance and mechanical properties and good corrosion resistance than the comparative example product. The addition of nano zirconium diboride, rhenium powder, nano tungsten carbide and rare earth is beneficial to improving the above properties.

[0091] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as described above. However, any technician familiar with the profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the scope of the technical solution of the present invention, which are all equivalent embodiments of the present invention. At the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A powder metallurgy material, characterized in that: The invention is prepared from the following components in percentage by weight: 3wt%-6wt% of graphene, 0.5wt%-1.5wt% of nano zirconium diboride, 6wt%-10wt% of copper powder, 0.8wt%-1.2wt% of manganese powder, 0.3wt%-0.6wt% of nano tungsten carbide, 0wt%-1wt% of lubricant, 0.01wt%-0.05wt% of rare earth, 0.1wt%-0.3wt% of niobium powder, 0.03wt%-0.05wt% of hafnium powder, 0.001wt%-0.003wt% of rhenium powder, 3wt%-5wt% of chromium powder, 0.01wt%-0.03wt% of binder, 0.1wt%-0.2wt% of bicyclo[2.2.1]heptanedimethylamine, 0.05wt%-0.15wt% of polyethersulfone type hyperbranched epoxy resin with epoxy end groups, and the balance is iron powder.

2. The powder metallurgy material according to claim 1, characterized in that: The graphene is a single-layer graphene with a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm; the particle size of the nano zirconium diboride is 30-80 nm; and the particle size of the nano tungsten carbide is 20-60 nm.

3. The powder metallurgy material according to claim 1, characterized in that: The particle size of the copper powder is 800-1200 mesh; the particle size of the manganese powder is 1000-1300 mesh; the particle size of the rare earth is 500-800 mesh; the particle size of the niobium powder is 800-1000 mesh; the particle size of the hafnium powder is 600-1000 mesh; the particle size of the rhenium powder is 900-1300 mesh; the particle size of the chromium powder is 800-1000 mesh; and the particle size of the iron powder is 1000-1400 mesh.

4. The powder metallurgy material according to claim 1, characterized in that: The lubricant is zinc stearate; the rare earth is at least one of lanthanum and cerium.

5. The powder metallurgy material according to claim 1, characterized in that: The binder is a mixture formed by mixing sodium silicate and sodium tripolyphosphate in a mass ratio of (3-5):

1.

6. A method for preparing a powder metallurgy material according to any one of claims 1 to 5, characterized in that: The steps include: Step S1, weigh each component according to mass percentage, put it into a mixer and mix it evenly; Step S2, placing the mixed raw materials into a mold, pressing to obtain a compact, and then sintering in a vacuum atmosphere or under nitrogen protection; Step S3: After heat treatment, a powder metallurgy material is obtained.

7. The method for preparing a powder metallurgy material according to claim 6, characterized in that: The heat treatment in step S3 includes quenching and tempering treatment; the quenching temperature is 1000-1100°C, the holding time is 1-2 hours, and the oil is cooled to room temperature; the tempering temperature is 650-700°C, and the tempering treatment time is 1-2 hours.

8. The method for preparing a powder metallurgy material according to claim 6, characterized in that: The sintering in step S2 is hot pressing sintering, the sintering temperature is 1250-1300° C., the holding time is 1-2 hours, and the pressure applied to the mold is 10-20 MPa; the pressing pressure in step S2 is 300-500 MPa.

9. Use of the powder metallurgy material according to any one of claims 1 to 5 in the preparation of automobile bearings.