A wear-resistant powder metallurgy special-shaped gear and its preparation method

Abstract

The invention provides a wear-resistant powder metallurgy special-shaped gear and a preparation method thereof, which relate to the technical field of gear materials. The gear is formed by pressing the following raw materials in parts by weight: 100 parts of iron powder, 0.5-1 parts of chromium powder, 0.001-0.003 parts of boron powder, 0.001-0.003 parts of silicon powder, 0.03-0.06 parts of hafnium powder, 0.1-0.3 parts of tungsten powder, 2-2.5 parts of copper powder, 0.2-0.4 parts of titanium powder, 0.01-0.03 parts of gallium powder, 0.01-0.03 parts of rhenium powder, 0.001-0.003 parts of iridium powder, 0.3-0.5 parts of corundum powder, 0.4-0.9 parts of brown corundum powder, 0.05-0.1 parts of nano-tungsten carbide, 0.01-0.03 parts of nano-tantalum nitride and 0.01-0.04 parts of rare earth powder. The gear has good mechanical properties, excellent corrosion resistance and wear resistance, and long service life.

Description

Technical Field

[0001] The invention relates to the technical field of gear materials, and in particular to a wear-resistant powder metallurgy special-shaped gear and a preparation method thereof. Background Art

[0002] Gears are commonly used components in the field of mechanical manufacturing. They are mainly used in transmission devices. They have good transmission accuracy, compact structure, reliable operation, and high transmission efficiency. Therefore, they are widely used in various mechanical equipment. Special-shaped gears are a common product among gears. During the meshing process, their instantaneous angular velocity ratio changes according to a certain established law of motion, which can realize special motion and function operations, which is very beneficial to the motion characteristics of the mechanism, can improve the performance of the mechanism, and improve the motion conditions of the mechanism. They have high market demand and value.

[0003] Special-shaped gears are subject to high stress during operation and need to withstand high wear and corrosion. In order to improve the working stability of the gears, the material of special-shaped gears should have high hardness, wear resistance and corrosion resistance. Existing special-shaped gears have serious wear, insufficient mechanical properties, insufficient corrosion resistance and wear resistance, and short service life. These defects greatly reduce the working reliability of special-shaped gears.

[0004] In order to solve the above problems, the Chinese invention patent with authorization announcement number CN103223484B discloses a powder metallurgy special-shaped gear, which is pressed from the following powder raw materials in parts by weight: iron powder 100, copper powder 1.8-2.0, molybdenum powder 0.5-0.8, vanadium powder 0.1-0.3, nickel powder 0.8-1.2, graphite powder 0.5-0.8, modified tree ash 0.1-0.3, rare earth ferrosilicon alloy 0.2-0.6, Cr powder 0.1-0.3, ethylene bis stearamide 0.1-0.2, silicon powder 0.1-0.3, yttrium powder 0.2-0.4, boron nitride 0.2-0.4, and molybdenum sulfide 0.4-0.5. During the preparation, the powder raw materials are first mixed in steps, and then pressed, sintered, heat treated, and surface treated to obtain the final product, the special-shaped gear. The produced powder metallurgy special-shaped gear has good mechanical properties, however, its wear resistance and corrosion resistance still need to be further improved.

[0005] It can be seen that the art still needs a wear-resistant powder metallurgy special-shaped gear with good mechanical properties, excellent corrosion resistance and wear resistance, and long service life, and a preparation method thereof. Summary of the invention

[0006] In view of the above problems, the object of the present invention is to provide a wear-resistant powder metallurgy special-shaped gear with good mechanical properties, excellent corrosion resistance and wear resistance, and long service life, and a preparation method thereof.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a wear-resistant powder metallurgy special-shaped gear is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.5-1 parts of chromium powder, 0.001-0.003 parts of boron powder, 0.001-0.003 parts of silicon powder, 0.03-0.06 parts of hafnium powder, 0.1-0.3 parts of tungsten powder, 2-2.5 parts of copper powder, 0.2-0.4 parts of titanium powder, 0.01-0.03 parts of gallium powder, 0.01-0.03 parts of rhenium powder, 0.001-0.003 parts of iridium powder, 0.3-0.5 parts of corundum powder, 0.4-0.9 parts of brown corundum powder, 0.05-0.1 parts of nano-tungsten carbide, 0.01-0.03 parts of nano-tantalum nitride, and 0.01-0.04 parts of rare earth powder.

[0008] Preferably, the raw materials for preparing the wear-resistant powder metallurgy special-shaped gears further include: 0.06-0.12 parts of hyperbranched polyetherimide epoxy compound, 0.02-0.04 parts of benzoguanamine, and 0.01-0.03 parts of 1,4-diamino-2,3-dicyanoanthraquinone.

[0009] Preferably, there is no special requirement for the source of the hyperbranched polyetherimide epoxy compound. In one embodiment of the present invention, the hyperbranched polyetherimide epoxy compound is prepared according to the method of Example 35 in Chinese invention patent CN110951076B.

[0010] Preferably, the rare earth powder is a mixture of scandium powder, yttrium powder and praseodymium powder in a mass ratio of 1:(0.8-1.2):(0.3-0.5).

[0011] Preferably, the particle size of the rare earth powder is 800-1200 mesh; the particle size of the corundum powder is 600-900 mesh; and the particle size of the brown corundum powder is 700-1000 mesh.

[0012] Preferably, the particle size of the nano-tungsten carbide is 10-60 nm; the particle size of the nano-tantalum nitride is 20-80 nm.

[0013] Preferably, the particle size of the iron powder is 800-1000 mesh; the particle size of the chromium powder is 1000-1200 mesh; the particle size of the boron powder is 900-1100 mesh; the particle size of the silicon powder is 1000-1200 mesh; the particle size of the hafnium powder is 800-1000 mesh; the particle size of the tungsten powder is 1000-1200 mesh; the particle size of the copper powder is 1300-1600 mesh; the particle size of the titanium powder is 1200-1500 mesh; the particle size of the gallium powder is 1100-1400 mesh; the particle size of the rhenium powder is 1000-1300 mesh; and the particle size of the iridium powder is 1000-1200 mesh.

[0014] Another object of the present invention is to provide a method for preparing the wear-resistant powder metallurgy special-shaped gear, comprising the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain a mixed powder; then loading them into a mold, pressing them into shape, and then sintering and heat treating them in sequence to obtain a wear-resistant powder metallurgy special-shaped gear.

[0015] Preferably, the compression molding pressure is 540-610 MPa.

[0016] Preferably, the sintering is hot pressing sintering, which is carried out in a protective atmosphere of nitrogen and is divided into two stages. The sintering temperature of the first stage is 1010-1060°C, and the sintering time is 15-25min. The sintering temperature of the second stage is 1170-1250°C, and the sintering time is 1-2h. The pressure applied to the mold during the sintering process is 22-35MPa.

[0017] Preferably, the heat treatment includes normalizing, tempering and quenching; the normalizing temperature is 820-860°C, the holding time is 40-70min, and then cooled in air; the tempering is a two-stage tempering, the first stage tempering temperature is 480-530°C, the holding time is 1-2h, the second stage tempering temperature is 150-200°C, and the holding time is 1-3h; the quenching temperature is 660-720°C, and then cooled with quenching oil after holding for 1-3 hours.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The method for preparing wear-resistant powder metallurgy special-shaped gears disclosed in the present invention has simple process and equipment, convenient operation, small impact on the environment, low energy consumption, high preparation efficiency and finished product qualification rate, is suitable for industrial production, and has high promotion and application value.

[0020] (2) The wear-resistant powder metallurgy special-shaped gear disclosed in the present invention is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.5-1 parts of chromium powder, 0.001-0.003 parts of boron powder, 0.001-0.003 parts of silicon powder, 0.001-0.003 parts of hafnium powder, 0.1-0.3 parts of tungsten powder, 2-2.5 parts of copper powder, 0.2-0.4 parts of titanium powder, 0.01-0.03 parts of gallium powder, 0.01-0.03 parts of rhenium powder, 0.001-0.003 parts of iridium powder, 0.3-0.5 parts of corundum powder, 0.4-0.9 parts of brown corundum powder, 0.05-0.1 parts of nano-tungsten carbide, 0.01-0.03 parts of nano-tantalum nitride, and 0.01-0.04 parts of rare earth powder. Through the mutual cooperation between the raw materials, the manufactured gears have good mechanical properties, excellent corrosion resistance and wear resistance, and long service life.

[0021] (3) The wear-resistant powder metallurgy special-shaped gear disclosed in the present invention is prepared by raw materials further including: 0.06-0.12 parts of hyperbranched polyetherimide epoxy compound, 0.02-0.04 parts of benzoguanamine, and 0.01-0.03 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the hyperbranched polyetherimide, benzoguanamine and cyanoanthraquinone structures are simultaneously introduced through the above components, and these structures, under the multiple effects of electronic effect, steric effect and conjugation effect, make the compatibility between the raw materials better, and cooperate with other raw materials to further improve the density of the internal structure of the material, improve the mechanical properties, corrosion resistance and wear resistance, and thus extend the service life of the gear. The epoxy group on the hyperbranched polyetherimide epoxy compound can undergo epoxy ring-opening reaction with the amino groups on benzoguanamine and 1,4-diamino-2,3-dicyanoanthraquinone to form an interpenetrating network structure, further improving the above properties. DETAILED DESCRIPTION

[0022] 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.

[0023] Example 1

[0024] A wear-resistant powder metallurgy special-shaped gear is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.5 parts of chromium powder, 0.001 parts of boron powder, 0.001 parts of silicon powder, 0.03 parts of hafnium powder, 0.1 parts of tungsten powder, 2 parts of copper powder, 0.2 parts of titanium powder, 0.01 parts of gallium powder, 0.01 parts of rhenium powder, 0.001 parts of iridium powder, 0.3 parts of corundum powder, 0.4 parts of brown corundum powder, 0.05 parts of nano-tungsten carbide, 0.01 parts of nano-tantalum nitride, and 0.01 parts of rare earth powder.

[0025] The raw materials for preparing the wear-resistant powder metallurgy special-shaped gears also include: 0.06 parts of hyperbranched polyetherimide epoxy compound, 0.02 parts of benzoguanamine, and 0.01 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the hyperbranched polyetherimide epoxy compound is prepared according to the method of Example 35 in Chinese invention patent CN110951076B.

[0026] The particle size of the rare earth powder is 800 mesh; the rare earth powder is a mixture of scandium powder, yttrium powder and praseodymium powder in a mass ratio of 1:0.8:0.3; the particle size of the corundum powder is 600 mesh; the particle size of the brown corundum powder is 700 mesh; the particle size of the nano tungsten carbide is 10nm; the particle size of the nano tantalum nitride is 20nm; the particle size of the iron powder is 800 mesh; the particle size of the chromium powder is 1000 mesh; the particle size of the boron powder is 900 mesh; the particle size of the silicon powder is 1000 mesh; the particle size of the hafnium powder is 800 mesh; the particle size of the tungsten powder is 1000 mesh; the particle size of the copper powder is 1300 mesh; the particle size of the titanium powder is 1200 mesh; the particle size of the gallium powder is 1100 mesh; the particle size of the rhenium powder is 1000 mesh; the particle size of the iridium powder is 1000 mesh.

[0027] A method for preparing the wear-resistant powder metallurgy special-shaped gear comprises the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain a mixed powder; then loading them into a mold, pressing and forming them, and then sintering and heat treating them in sequence to obtain a wear-resistant powder metallurgy special-shaped gear.

[0028] The pressing pressure is 540MPa; the sintering is hot pressing sintering, which is carried out in a nitrogen protective atmosphere and is divided into two stages. The sintering temperature of the first stage is 1010°C and the sintering time is 15min, and the sintering temperature of the second stage is 1170°C and the sintering time is 1h. The pressure applied to the mold during the sintering process is 22MPa; the heat treatment includes normalizing, tempering and quenching; the normalizing temperature is 820°C, the holding time is 40min, and then cooled in air; the tempering is a two-stage tempering, the first stage tempering temperature is 480°C, the holding time is 1h, the second stage tempering temperature is 150°C, and the holding time is 1h; the quenching temperature is 660°C and kept for 1 hour and then cooled with quenching oil.

[0029] Example 2

[0030] A wear-resistant powder metallurgy special-shaped gear is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.6 parts of chromium powder, 0.0015 parts of boron powder, 0.0015 parts of silicon powder, 0.04 parts of hafnium powder, 0.15 parts of tungsten powder, 2.2 parts of copper powder, 0.25 parts of titanium powder, 0.015 parts of gallium powder, 0.015 parts of rhenium powder, 0.0015 parts of iridium powder, 0.35 parts of corundum powder, 0.5 parts of brown corundum powder, 0.06 parts of nano-tungsten carbide, 0.015 parts of nano-tantalum nitride, and 0.02 parts of rare earth powder.

[0031] The raw materials for preparing the wear-resistant powder metallurgy special-shaped gears also include: 0.08 parts of hyperbranched polyetherimide epoxy compound, 0.025 parts of benzoguanamine, and 0.015 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the hyperbranched polyetherimide epoxy compound is prepared according to the method of Example 35 in Chinese invention patent CN110951076B.

[0032] The particle size of the rare earth powder is 900 mesh; the rare earth powder is a mixture of scandium powder, yttrium powder and praseodymium powder in a mass ratio of 1:0.9:0.35; the particle size of the corundum powder is 700 mesh; the particle size of the brown corundum powder is 800 mesh; the particle size of the nano tungsten carbide is 20nm; the particle size of the nano tantalum nitride is 40nm; the particle size of the iron powder is 850 mesh; the particle size of the chromium powder is 1050 mesh; the particle size of the boron powder is 950 mesh; the particle size of the silicon powder is 1050 mesh; the particle size of the hafnium powder is 850 mesh; the particle size of the tungsten powder is 1050 mesh; the particle size of the copper powder is 1400 mesh; the particle size of the titanium powder is 1300 mesh; the particle size of the gallium powder is 1200 mesh; the particle size of the rhenium powder is 1100 mesh; the particle size of the iridium powder is 1050 mesh.

[0033] A preparation method of the wear-resistant powder metallurgy special-shaped gear comprises the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain a mixed powder; then loading them into a mold, pressing and forming them, and then sintering and heat treating them in sequence to obtain a wear-resistant powder metallurgy special-shaped gear; the pressing and forming pressure is 560MPa; the sintering is hot pressing sintering, which is carried out in a nitrogen protective atmosphere and is divided into two stages, the sintering temperature of the first stage is 1030°C, the sintering time is 17min, and the sintering temperature of the second stage is 1190°C. The sintering time is 1.2h, and the pressure applied to the mold during the sintering process is 26MPa; the heat treatment includes normalizing, tempering and quenching; the temperature of the normalizing is 830℃, the holding time is 50min, and then cooled in the air; the tempering is a two-stage tempering, the temperature of the first stage tempering is 490℃, the holding time is 1.2h, the temperature of the second stage tempering is 160℃, and the holding time is 1.5h; the temperature of the quenching is 680℃, kept for 1.5 hours, and then cooled with quenching oil.

[0034] Example 3

[0035] A wear-resistant powder metallurgy special-shaped gear is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.8 parts of chromium powder, 0.002 parts of boron powder, 0.002 parts of silicon powder, 0.045 parts of hafnium powder, 0.2 parts of tungsten powder, 2.3 parts of copper powder, 0.3 parts of titanium powder, 0.02 parts of gallium powder, 0.02 parts of rhenium powder, 0.002 parts of iridium powder, 0.4 parts of corundum powder, 0.7 parts of brown corundum powder, 0.07 parts of nano-tungsten carbide, 0.02 parts of nano-tantalum nitride, and 0.025 parts of rare earth powder.

[0036] The raw materials for preparing the wear-resistant powder metallurgy special-shaped gears also include: 0.09 parts of hyperbranched polyetherimide epoxy compound, 0.03 parts of benzoguanamine, and 0.02 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the hyperbranched polyetherimide epoxy compound is prepared according to the method of Example 35 in Chinese invention patent CN110951076B.

[0037] The particle size of the rare earth powder is 1000 mesh; the rare earth powder is a mixture of scandium powder, yttrium powder and praseodymium powder in a mass ratio of 1:1:0.4; the particle size of the corundum powder is 750 mesh; the particle size of the brown corundum powder is 850 mesh; the particle size of the nano tungsten carbide is 40nm; the particle size of the nano tantalum nitride is 60nm; the particle size of the iron powder is 900 mesh; the particle size of the chromium powder is 1100 mesh; the particle size of the boron powder is 1000 mesh; the particle size of the silicon powder is 1100 mesh; the particle size of the hafnium powder is 900 mesh; the particle size of the tungsten powder is 1100 mesh; the particle size of the copper powder is 1450 mesh; the particle size of the titanium powder is 1350 mesh; the particle size of the gallium powder is 1250 mesh; the particle size of the rhenium powder is 1200 mesh; the particle size of the iridium powder is 1100 mesh.

[0038] A preparation method of the wear-resistant powder metallurgy special-shaped gear comprises the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain a mixed powder; then putting them into a mold, pressing and forming them, and then sintering and heat treating them in sequence to obtain a wear-resistant powder metallurgy special-shaped gear; the pressing and forming pressure is 590MPa; the sintering is hot pressing sintering, which is carried out in a nitrogen protective atmosphere and is divided into two stages, the sintering temperature of the first stage is 1030°C, the sintering time is 20min, and the sintering temperature of the second stage is 1220 ℃, sintering time is 1.5h, and the pressure applied to the mold during sintering is 29MPa; the heat treatment includes normalizing treatment, tempering treatment and quenching treatment; the temperature of the normalizing treatment is 840℃, the holding time is 55min, and then cooled in air; the tempering treatment is a two-stage tempering treatment, the temperature of the first stage tempering treatment is 510℃, the holding time is 1.5h, the temperature of the second stage tempering treatment is 180℃, and the holding time is 2h; the temperature of the quenching treatment is 690℃, and then cooled with quenching oil after keeping warm for 2 hours.

[0039] Example 4

[0040] A wear-resistant powder metallurgy special-shaped gear is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.9 parts of chromium powder, 0.0025 parts of boron powder, 0.0025 parts of silicon powder, 0.055 parts of hafnium powder, 0.25 parts of tungsten powder, 2.4 parts of copper powder, 0.35 parts of titanium powder, 0.025 parts of gallium powder, 0.025 parts of rhenium powder, 0.0025 parts of iridium powder, 0.45 parts of corundum powder, 0.8 parts of brown corundum powder, 0.09 parts of nano-tungsten carbide, 0.025 parts of nano-tantalum nitride, and 0.035 parts of rare earth powder.

[0041] The raw materials for preparing the wear-resistant powder metallurgy special-shaped gears also include: 0.11 parts of hyperbranched polyetherimide epoxy compound, 0.035 parts of benzoguanamine, and 0.025 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the hyperbranched polyetherimide epoxy compound is prepared according to the method of Example 35 in Chinese invention patent CN110951076B.

[0042] The particle size of the rare earth powder is 1150 mesh; the rare earth powder is a mixture of scandium powder, yttrium powder and praseodymium powder in a mass ratio of 1:1.1:0.45; the particle size of the corundum powder is 850 mesh; the particle size of the brown corundum powder is 950 mesh; the particle size of the nano tungsten carbide is 50nm; the particle size of the nano tantalum nitride is 70nm; the particle size of the iron powder is 950 mesh; the particle size of the chromium powder is The particle size of the boron powder is 1050 mesh; the particle size of the silicon powder is 1150 mesh; the particle size of the hafnium powder is 950 mesh; the particle size of the tungsten powder is 1150 mesh; the particle size of the copper powder is 1550 mesh; the particle size of the titanium powder is 1450 mesh; the particle size of the gallium powder is 1350 mesh; the particle size of the rhenium powder is 1250 mesh; and the particle size of the iridium powder is 1150 mesh.

[0043] A preparation method of the wear-resistant powder metallurgy special-shaped gear comprises the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain a mixed powder; then loading them into a mold, pressing and forming them, and then sintering and heat treating them in sequence to obtain a wear-resistant powder metallurgy special-shaped gear; the pressing and forming pressure is 600MPa; the sintering is hot pressing sintering, which is carried out in a nitrogen protective atmosphere and is divided into two stages, the sintering temperature of the first stage is 1050°C, the sintering time is 23min, and the sintering temperature of the second stage is 1240°C. The sintering time is 1.8h, and the pressure applied to the mold during the sintering process is 33MPa; the heat treatment includes normalizing, tempering and quenching; the temperature of the normalizing is 855°C, the holding time is 65min, and then cooled in the air; the tempering is a two-stage tempering, the temperature of the first stage tempering is 520°C, the holding time is 1.8h, the temperature of the second stage tempering is 190°C, and the holding time is 2.5h; the temperature of the quenching is 710°C, kept for 2.5 hours, and then cooled with quenching oil.

[0044] Example 5

[0045] A wear-resistant powder metallurgy special-shaped gear is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 1 part of chromium powder, 0.003 parts of boron powder, 0.003 parts of silicon powder, 0.06 parts of hafnium powder, 0.3 parts of tungsten powder, 2.5 parts of copper powder, 0.4 parts of titanium powder, 0.03 parts of gallium powder, 0.03 parts of rhenium powder, 0.003 parts of iridium powder, 0.5 parts of corundum powder, 0.9 parts of brown corundum powder, 0.1 parts of nano-tungsten carbide, 0.03 parts of nano-tantalum nitride, and 0.04 parts of rare earth powder.

[0046] The raw materials for preparing the wear-resistant powder metallurgy special-shaped gear also include: 0.06-0.12 parts of hyperbranched polyetherimide epoxy compound, 0.04 parts of benzoguanamine, and 0.03 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the hyperbranched polyetherimide epoxy compound is prepared according to the method of Example 35 in Chinese invention patent CN110951076B;

[0047] The particle size of the rare earth powder is 1200 mesh; the rare earth powder is a mixture of scandium powder, yttrium powder and praseodymium powder in a mass ratio of 1:1.2:0.5; the particle size of the corundum powder is 900 mesh; the particle size of the brown corundum powder is 1000 mesh; the particle size of the nano tungsten carbide is 60nm; the particle size of the nano tantalum nitride is 80nm; the particle size of the iron powder is 1000 mesh; the particle size of the chromium powder is The particle size of the boron powder is 1100 mesh; the particle size of the silicon powder is 1200 mesh; the particle size of the hafnium powder is 1000 mesh; the particle size of the tungsten powder is 1200 mesh; the particle size of the copper powder is 1600 mesh; the particle size of the titanium powder is 1500 mesh; the particle size of the gallium powder is 1400 mesh; the particle size of the rhenium powder is 1300 mesh; and the particle size of the iridium powder is 1200 mesh.

[0048] A preparation method of the wear-resistant powder metallurgy special-shaped gear comprises the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain a mixed powder; then putting them into a mold, pressing and forming them, and then sintering and heat treating them in sequence to obtain a wear-resistant powder metallurgy special-shaped gear; the pressing and forming pressure is 610MPa; the sintering is hot pressing sintering, which is carried out in a nitrogen protective atmosphere and is divided into two stages, the sintering temperature of the first stage is 1060°C, the sintering time is 25min, and the sintering temperature of the second stage is 12 50℃, sintering time is 2h, and the pressure applied to the mold during sintering is 35MPa; the heat treatment includes normalizing, tempering and quenching; the temperature of the normalizing is 860℃, the holding time is 70min, and then cooled in air; the tempering is a two-stage tempering, the temperature of the first stage tempering is 530℃, the holding time is 2h, the temperature of the second stage tempering is 200℃, and the holding time is 3h; the temperature of the quenching is 720℃, and then cooled with quenching oil after holding for 3 hours.

[0049] Comparative Example 1

[0050] A wear-resistant powder metallurgy special-shaped gear and a preparation method thereof, which are basically the same as Example 1, except that nano tantalum nitride, boron powder, silicon powder and benzoguanamine are not added.

[0051] Comparative Example 2

[0052] A wear-resistant powder metallurgy special-shaped gear and a preparation method thereof, which are basically the same as Example 1, except that rhenium powder, rare earth powder and 1,4-diamino-2,3-dicyanoanthraquinone are not added.

[0053] In order to further illustrate the unexpected positive technical effects achieved by the wear-resistant powder metallurgy special-shaped gear products involved in each embodiment of the present invention, relevant performance tests were conducted on the wear-resistant powder metallurgy special-shaped gears manufactured in each example. The test results are shown in Table 1. The test method is as follows:

[0054] (1) Tensile strength: Tested in accordance with standard GB / T228-2002 “Room temperature tensile test method for metal materials”.

[0055] (2) Corrosion resistance: The wear-resistant powder metallurgy special-shaped gears are subjected to a salt spray corrosion test at a test temperature of 35°C. A 5% mass concentration sodium chloride aqueous solution is sprayed in the test chamber to simulate the accelerated corrosion of the environment. Gears are considered to be corrosion resistant if their tolerance time (i.e., the time they remain rust-free) exceeds 1,600 hours; otherwise, they are considered to be unqualified.

[0056] (3) Wear resistance: The friction and wear of each wear-resistant powder metallurgy special-shaped gear sample was tested using a MFT-R4000 high-speed reciprocating friction and wear tester. The test load was 30 N, the test time was 5 min, the friction length was 5 × 10-3 m, and the friction ball was φ4 mm Al2O3 material. The wear volume of the material after friction and wear was measured using a three-dimensional topography instrument to obtain the wear rate. The wear rate W is calculated using the following formula: W = m / N·L, where W is the wear rate (g / N·m); m is the wear mass (g); N is the load (N); and L is the total stroke (m).

[0057] Table 1

[0058] project tensile strength Wear rate Corrosion resistance unit MPa <![CDATA[×10 -10 g / N·m]]> — Example 1 1183 0.10 qualified Example 2 1190 0.08 qualified Example 3 1195 0.06 qualified Example 4 1205 0.05 qualified Example 5 1213 0.03 qualified Comparative Example 1 1033 0.25 Failure Comparative Example 2 1096 0.37 Failure

[0059] As can be seen from Table 1, the wear-resistant powder metallurgy special-shaped gear disclosed in the embodiment of the present invention has more excellent mechanical properties, wear resistance and corrosion resistance than the comparative product; the addition of nano tantalum nitride, boron powder, silicon powder, benzoguanamine, rhenium powder, rare earth powder and 1,4-diamino-2,3-dicyanoanthraquinone is beneficial to improving the above properties.

[0060] 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 wear-resistant powder metallurgy special-shaped gear, characterized in that: The invention is pressed from the following raw materials in parts by weight: 100 parts of iron powder, 0.5-1 parts of chromium powder, 0.001-0.003 parts of boron powder, 0.001-0.003 parts of silicon powder, 0.03-0.06 parts of hafnium powder, 0.1-0.3 parts of tungsten powder, 2-2.5 parts of copper powder, 0.2-0.4 parts of titanium powder, 0.01-0.03 parts of gallium powder, 0.01-0.03 parts of rhenium powder, 0.001-0.003 parts of iridium powder, 0.3-0.5 parts of corundum powder, 0.4 -0.9 parts, 0.05-0.1 parts of nano-tungsten carbide, 0.01-0.03 parts of nano-tantalum nitride, 0.01-0.04 parts of rare earth powder, 0.06-0.12 parts of hyperbranched polyetherimide epoxy compound, 0.02-0.04 parts of benzoguanamine, and 0.01-0.03 parts of 1,4-diamino-2,3-dicyanoanthraquinone; the rare earth powder is a mixture of scandium powder, yttrium powder, and praseodymium powder in a mass ratio of 1:(0.8-1.2):(0.3-0.5).

2. The wear-resistant powder metallurgy special-shaped gear according to claim 1, characterized in that: The particle size of the rare earth powder is 800-1200 mesh; the particle size of the corundum powder is 600-900 mesh; the particle size of the brown corundum powder is 700-1000 mesh; the particle size of the nano-tungsten carbide is 10-60nm; and the particle size of the nano-tantalum nitride is 20-80nm.

3. The wear-resistant powder metallurgy special-shaped gear according to claim 1, characterized in that: The particle size of the iron powder is 800-1000 mesh; the particle size of the chromium powder is 1000-1200 mesh; the particle size of the boron powder is 900-1100 mesh; the particle size of the silicon powder is 1000-1200 mesh; the particle size of the hafnium powder is 800-1000 mesh; the particle size of the tungsten powder is 1000-1200 mesh; the particle size of the copper powder is 1300-1600 mesh; the particle size of the titanium powder is 1200-1500 mesh; the particle size of the gallium powder is 1100-1400 mesh; the particle size of the rhenium powder is 1000-1300 mesh; and the particle size of the iridium powder is 1000-1200 mesh.

4. A method for preparing a wear-resistant powder metallurgy special-shaped gear according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing the raw materials by weight, putting them into a mixer and mixing them evenly to obtain mixed powder; then putting them into a mold, pressing and forming them, and then sintering and heat treating them in sequence to obtain wear-resistant powder metallurgy special-shaped gears.

5. A method for preparing a wear-resistant powder metallurgy special-shaped gear as claimed in claim 4, characterized in that: The compression molding pressure is 540-610 MPa.

6. A method for preparing a wear-resistant powder metallurgy special-shaped gear as claimed in claim 4, characterized in that: The sintering is hot pressing sintering, which is carried out in a nitrogen protective atmosphere and is divided into two stages. The sintering temperature of the first stage is 1010-1060°C and the sintering time is 15-25min. The sintering temperature of the second stage is 1170-1250°C and the sintering time is 1-2h. The pressure applied to the mold during the sintering process is 22-35MPa.

7. The method for preparing wear-resistant powder metallurgy special-shaped gears according to claim 4, characterized in that: The heat treatment includes normalizing treatment, tempering treatment and quenching treatment.

8. The method for preparing wear-resistant powder metallurgy special-shaped gears according to claim 7, characterized in that: The normalizing treatment is carried out at a temperature of 820-860°C, a holding time of 40-70 minutes, and then cooled in the air; the tempering treatment is a two-stage tempering treatment, the first stage tempering treatment is carried out at a temperature of 480-530°C, a holding time of 1-2 hours, and the second stage tempering treatment is carried out at a temperature of 150-200°C, a holding time of 1-3 hours; the quenching treatment is carried out at a temperature of 660-720°C, and then cooled with quenching oil after holding for 1-3 hours.