A diamond-containing alloy abrasive material and preparation method thereof

Abstract

The present invention relates to the technical field of tools for grinding, polishing or sharpening, and in particular to an alloy abrasive material containing diamond and a preparation method thereof. The alloy abrasive material comprises the following raw materials in parts by weight: 70 to 90 parts of a composite binder, 10 to 20 parts of diamonds and 1 to 5 parts of an adhesive wetting agent. The present invention also provides a preparation method thereof. The binder obtained by compounding the polymer and the metal in the present invention not only has good self-sharpening properties but is also easy to trim. The composite binder is mixed with the diamond to prepare an abrasive tool, so that the abrasive tool can better maintain its sharpness during operation, thereby improving the final quality of the workpiece processing surface.

Description

Technical Field

[0001] The invention relates to the technical field of tools for grinding, polishing or sharpening, and in particular to an alloy grinding tool material containing diamond and a preparation method thereof. Background Art

[0002] Diamond is a mineral composed of carbon, an allotrope of graphite, and is known for its extraordinary hardness, refractive index and color. Diamonds are divided into two categories: natural diamonds and synthetic diamonds. Synthetic diamonds are prepared by high temperature and high pressure (HPHT) or chemical vapor deposition (CVD). Diamonds are widely used in the industrial field, especially in the manufacture of tools that require high hardness and wear resistance. Diamond-containing alloy abrasive materials usually refer to diamonds as abrasives combined with metal binders (such as bronze, cobalt-based, tungsten-based and iron-based) for the manufacture of various abrasives and cutting tools. These alloy abrasive materials can provide excellent wear resistance, impact toughness, thermal stability and structural uniformity. Diamond abrasives are ideal tools for grinding cemented carbide. Diamond polycrystalline composite sheets or natural large single crystals can be made into turning tools, milling cutters, etc., which are used for finishing non-ferrous metal parts and non-metallic materials such as plastics and ceramics.

[0003] Metal bond diamond abrasives can be divided into many different categories according to the metal type and alloy composition, including nickel-based, aluminum-based, bronze and carbide-based bonds. The manufacture of this type of abrasives mainly relies on two forming technologies: cold pressing and hot pressing. The cold pressing process requires a large amount of pressure, which may cause the diamond particles to break during the forming process. At the same time, in order to avoid oxidation of metal powder and diamond during the sintering process, it must be carried out in a protective atmosphere. Due to these limitations, hot pressing technology has become the preferred method for manufacturing metal bond diamond abrasives because it does not require a protective atmosphere and can be formed in one go, and has been widely used in the industry. Resin bond diamond abrasives are mainly based on resin powder as the bonding material, and filler materials are added at the same time. Through a series of processes such as hot pressing, curing and machine processing, resin bond diamond abrasive products with a certain shape are prepared. Resin-bonded diamond abrasives have many excellent properties. For example, they have high grinding efficiency and good self-sharpening performance during grinding. The grinding heat is not high during the processing, which is not easy to cause the workpiece to burn. At the same time, the grinding wheel is not easy to clog and dressing is relatively easy. At the same time, the elasticity of the resin bond is good, and it can be widely used in polishing, semi-finishing or fine grinding. Secondly, the preparation process of resin-bonded diamond abrasives is relatively simple compared with the preparation process of metal-bonded diamond abrasives and ceramic-bonded diamond abrasives, and the preparation cost is relatively low.

[0004] CN114645171A belongs to the field of preparation of diamond composite materials, and specifically relates to a multi-principal alloy-diamond abrasive material and its preparation method and application. The raw materials of the composite material include 80-95vol% of bonding phase powder and 5-20vol% of diamond. The bonding phase powder used is composed of Cu, Ni, Fe, Sn, and Ti in an atomic ratio of (20-50): (10-40): (5-30): (1-10): (1-10). The preparation method is: after the bonding phase powder and the diamond powder are fully mixed, the product is sintered at 850-1100℃ by spark plasma sintering SPS or hot pressing HP process. The material has good interface bonding, diamond stability, friction and wear performance, and high fracture strength. The multi-principal alloy-diamond abrasive material designed and prepared by the invention can be used to prepare diamond grinding discs, diamond grinding wheels and other grinding diamond tools.

[0005] CN108747852A discloses a diamond grinding tool, the raw materials of which include: a composite binder and a diamond abrasive, and the raw materials of the composite binder include: a metal binder and a composite resin binder. The invention also proposes a method for preparing a diamond grinding tool, which includes the following steps: adding copper-palladium-praseodymium pre-alloy powder, manganese powder, silver powder, tungsten carbide powder, nano-molecular sieve, diamond abrasive and a wetting agent to a ball mill to mix to obtain a premix; adding polyimide resin powder, polyketone resin powder and a curing agent to the premix to mix evenly to obtain a pre-pressed material; cold-pressing the pre-pressed material into a metal-bonded diamond tool by hot pressing and sintering. The diamond grinding tool of the invention has high bonding strength, high grinding efficiency and broad application prospects.

[0006] Metal bond diamond abrasives currently have a series of problems, such as low porosity, poor heat dissipation, easy burns on workpieces during processing, and difficulty in sharpening, which limit their scope of use. Resin bond diamond abrasives have problems of poor durability and low strength. Summary of the invention

[0007] In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide an alloy grinding tool material containing diamond and a preparation method thereof.

[0008] Diamond abrasives are mainly divided into three categories: resin bond, metal bond and ceramic bond, each type has its specific limitations and defects. The performance of resin bond diamond abrasives will significantly decrease under high temperature conditions, because the heat generated during the grinding process will cause the bonding force of the resin bond to weaken rapidly, making the diamond particles easy to fall off, thereby limiting its scope of application. Ceramic bond diamond abrasives, due to their greater brittleness, perform generally in terms of fracture toughness and bending strength. Metal bond diamond abrasives have fewer pores, which makes it difficult to dissipate the heat generated during the processing, which may cause burns to the workpiece, affect the processing quality, and even cause irreversible damage to the workpiece. Therefore, the present invention provides a composite binder, which is obtained by combining a polymer with a metal. The obtained polymer has asymmetric structural units and a large number of rigid groups, so it has better temperature resistance and strength. The binder obtained after compounding with the metal is not only self-sharpening but also easy to trim. The composite binder is mixed with diamond to prepare an abrasive, wherein the metal powder plays a structural support role in the abrasive, which ensures that the abrasive has the necessary strength and hardness. The addition of polymer resin enhances the elasticity and self-sharpening ability of the abrasive tool, which enables the abrasive tool to better maintain its sharpness during work, thereby improving the final quality of the workpiece processing surface.

[0009] The present invention polymerizes a diamine monomer with 3,4'-diaminodiphenyl ether, 4.4-diisobenzofuran-1,1,3,3-tetraketone and 4-phenylethynylphthalic anhydride to obtain a polymer resin. Since the obtained polymer has an asymmetric structural unit and a large number of rigid groups, it has better temperature resistance and strength. When the diamine has a difluorene structure, since the difluorene has a special rigid planar biphenyl structure, it is more stable than a diphenyl ring structure. When the diamine monomer has a spirobifluorene structure, since the spirobifluorene compound has a special three-dimensional orthogonal structure and spirobifluorene has a spiro conjugation effect, it is helpful to improve the thermal stability and rigidity of the molecule, resulting in better temperature resistance and strength.

[0010] To achieve the above object, the present invention provides a diamond-containing alloy abrasive material, comprising the following raw materials in parts by weight: 70 to 90 parts of a composite binder, 10 to 20 parts of diamonds, and 1 to 5 parts of an adhesive wetting agent.

[0011] The preparation method of the composite binder comprises the following steps:

[0012] S1: diamine monomers are mixed with 3,4'-diaminodiphenyl ether, 4,4-diisobenzofuran-1,1,3,3-tetraketone, and 4-phenylethynylphthalic anhydride in a solvent, toluene is added continuously, the temperature is raised, and polymerization is carried out under an inert atmosphere. After the reaction is completed, the polymer is obtained by post-treatment.

[0013] S2. Evenly mix the polymer resin and the metal powder to obtain a composite binder.

[0014] Furthermore, the adhesive wetting agent is paraffin or glycerin.

[0015] Furthermore, the preparation method of the composite binder comprises the following steps:

[0016] S1: Add diamine monomer and 3,4'-diaminodiphenyl ether to 8 to 15 times the volume of N-methylpyrrolidone, mix well, add 4,4-diisobenzofuran-1,1,3,3-tetraketone and 4-phenylethynylphthalic anhydride, add toluene, heat up, and polymerize under an inert atmosphere. After the reaction is completed, cool to room temperature and pour into 5 to 10 times the volume of ethanol. Precipitation appears, filter, wash the residue with ethanol and water, dry, and grind to obtain a polymer resin.

[0017] S2. Evenly mix the polymer resin and the metal powder in a mass ratio of 1:5 to 6 to obtain a composite binder.

[0018] Preferably, the diamine monomer is one of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-dimethylfluorene-2,7-diamine, and 9,9'-spirobis[9H-fluorene]-2,2'-diamine.

[0019] Preferably, the molar ratio of the diamine monomer to 3,4'-diaminodiphenyl ether, 4,4-diisobenzofuran-1,1,3,3-tetraone, and 4-phenylethynylphthalic anhydride is 1-2:0.1-1:1-2:1-2.5.

[0020] Preferably, the temperature range of the heating is 160-200°C.

[0021] Preferably, the polymerization time is 6 to 10 hours.

[0022] Preferably, the volume of toluene is 0.2 to 0.4 times that of N-methylpyrrolidone.

[0023] Preferably, the metal powder is a mixture of two or more of copper, cobalt, iron, tin and zinc.

[0024] The invention also provides a method for preparing the alloy grinding tool material containing diamond.

[0025] A method for preparing a diamond-containing alloy abrasive tool material comprises the following steps:

[0026] The composite binder, diamond and adhesive wetting agent are mixed by ball milling, pre-pressed into a shape, and then sintered and trimmed to obtain the diamond-containing abrasive tool material.

[0027] Furthermore, the ball milling time is 3 to 6 hours.

[0028] Furthermore, the pre-pressing pressure is 10-30 MPa.

[0029] Furthermore, the sintering temperature is 400-800° C., the pressure is 30-50 MPa, and the sintering time is 2-4 hours.

[0030] Beneficial effects of the present invention:

[0031] 1. Compared with the prior art, the present invention provides a composite binder, which is obtained by combining a polymer with a metal. The obtained polymer has asymmetric structural units and a large number of rigid groups, so it has better temperature resistance and strength. The binder obtained after compounding with the metal is not only self-sharpening but also easy to trim. The composite binder is mixed with diamond to prepare an abrasive tool, in which the metal powder plays a structural support role in the abrasive tool, which ensures that the abrasive tool has the necessary strength and hardness. The addition of polymer resin enhances the elasticity and self-sharpening ability of the abrasive tool, which enables the abrasive tool to better maintain its sharpness during operation, thereby improving the final quality of the workpiece processing surface.

[0032] 2. The present invention polymerizes diamine monomer with 3,4'-diaminodiphenyl ether, 4.4-diisobenzofuran-1,1,3,3-tetraketone and 4-phenylethynylphthalic anhydride to obtain a polymer resin. Since the obtained polymer has an asymmetric structural unit and a large number of rigid groups, it has better temperature resistance and strength. DETAILED DESCRIPTION

[0033] 9,9-dimethylfluorene-2,7-diamine, CAS: 216454-90-9.

[0034] 9,9'-spirobi[9H-fluorene]-2,2'-diamine, CAS: 67665-45-6.

[0035] 4,4-Diisobenzofuran-1,1,3,3-tetraone, [4,4'-Biisobenzofuran]-1,1',3,3'-tetrone, CAS: 3711-04-4.

[0036] Diamond, 100~200μm.

[0037] Polyimide, density: 1.3g / cm 3 , average particle size: 30~40μm, Wuhan Zhisheng Technology Co., Ltd.

[0038] Example 1

[0039] A method for preparing a diamond-containing alloy abrasive material comprises the following steps, measured in parts by weight:

[0040] 82 parts of composite binder, 15 parts of diamond and 3 parts of glycerol were ball-milled for 4 hours and then pre-pressed at 20 MPa, and then sintered at 650°C and 45 MPa for 3 hours. After finishing, the alloy abrasive material containing diamond was obtained.

[0041] The preparation method of the composite binder comprises the following steps, measured in parts by weight:

[0042] S1 Add 6.15 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 1 part of 3,4'-diaminodiphenyl ether to 12 times the volume of N-methylpyrrolidone, mix well, add 3.67 parts of 4,4-diisobenzofuran-1,1,3,3-tetraketone and 4.16 parts of 4-phenylethynylphthalic anhydride, add toluene 0.3 times the volume of N-methylpyrrolidone, heat to 185°C, polymerize under nitrogen atmosphere for 9 hours, cool to room temperature after the reaction, pour into 8 times the volume of ethanol, precipitate appears, filter, wash the residue with ethanol and water, dry and grind to obtain polymer resin.

[0043] S2. Evenly mix 12 parts of polymer resin with 20 parts of copper, 20 parts of cobalt, 15 parts of iron and 15 parts of tin to obtain a composite binder.

[0044] Example 2

[0045] The method is substantially the same as Example 1, except that 6.15 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]propane is replaced by 3.36 parts of 9,9-dimethylfluorene-2,7-diamine.

[0046] Example 3

[0047] The method is substantially the same as Example 1, except that 6.15 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]propane is replaced by 5.19 parts of 9,9'-spirobi[9H-fluorene]-2,2'-diamine.

[0048] Comparative Example 1

[0049] A method for preparing a diamond-containing alloy abrasive material comprises the following steps, measured in parts by weight:

[0050] 82 parts of composite binder, 15 parts of diamond and 3 parts of glycerol were ball-milled for 4 hours and then pre-pressed at 20 MPa, and then sintered at 650°C and 45 MPa for 3 hours. After trimming, the diamond-containing abrasive material was obtained.

[0051] The preparation method of the composite binder comprises the following steps, measured in parts by weight:

[0052] Evenly mix 12 parts of polyimide with 20 parts of copper, 20 parts of cobalt, 15 parts of iron and 15 parts of tin to obtain a composite binder.

[0053] Comparative Example 2

[0054] A method for preparing a diamond-containing alloy abrasive material comprises the following steps, measured in parts by weight:

[0055] 82 parts of composite binder, 15 parts of diamond and 3 parts of glycerol were ball-milled for 4 hours and then pre-pressed at 20 MPa, and then sintered at 650°C and 45 MPa for 3 hours. After trimming, the diamond-containing abrasive material was obtained.

[0056] The preparation method of the composite binder comprises the following steps, measured in parts by weight:

[0057] Evenly mix 20 parts of copper, 20 parts of cobalt, 15 parts of iron and 15 parts of tin to obtain a composite binder.

[0058] Test Example 1

[0059] The hardness and bending strength of the alloy abrasive materials prepared in the embodiment and the control example were tested, wherein the hardness was tested by a Rockwell hardness tester, and the bending strength was tested according to the method in GB / T2567-2021 “Test method for properties of resin castings”. The specific results are shown in Table 1.

[0060] Table 1 Performance test results of diamond-containing alloy abrasive materials

[0061] Experimental protocol Hardness / HRB Bending strength / MPa Example 1 85 742.3 Example 2 93 823.5 Example 3 98 850.1 Comparative Example 1 80 623.2

[0062] It can be seen from Table 1 that the alloy abrasive tool obtained in the embodiment has greater hardness and bending strength than that in the control example 1. This may be because compared with the polyimide resin in the control example 1, the polymer prepared in the embodiment has an asymmetric structural unit and a large number of rigid groups, so the temperature resistance and strength are better, and the diamine monomer in the embodiment 2 has a difluorene structure. Since difluorene has a special rigid planar biphenyl structure, it is more stable than the diphenyl ring structure, and the diamine monomer in the embodiment 3 has a spirobifluorene structure. Spirobifluorene compounds have a special three-dimensional orthogonal structure, and there is a spiro conjugation effect inside the spirobifluorene, which helps to improve the rigidity of the molecule, resulting in greater hardness and higher bending strength.

[0063] Test Example 2

[0064] The grinding performance of the alloy abrasive tool materials prepared in the examples and the comparative examples was tested. The grinding was performed at a grinding wheel speed of 3200 rpm for 30 min, and the abrasive tool loss and grinding ratio were tested. The specific results are shown in Table 2.

[0065] Table 2 Grinding performance test results of diamond-containing alloy abrasive materials

[0066] Experimental protocol Loss / mg Grinding ratio Example 1 17.8 245.2 Example 2 14.7 310.4 Example 3 12.6 445.6 Comparative Example 1 26.2 156.8 Comparative Example 2 35.6 68.5

[0067] Grinding ratio is an important indicator for evaluating grinding efficiency. It refers to the ratio of the volume of metal removed between two dressings of the grinding wheel to the volume of grinding wheel wear. A large grinding ratio indicates, to a certain extent, a longer grinding wheel life. A reduced grinding ratio will increase the number of grinding wheel dressing and replacement, thereby increasing grinding wheel consumption and grinding costs. Therefore, a larger grinding ratio usually means a longer grinding wheel life, higher grinding efficiency, and better economy.

[0068] As can be seen from Table 2, compared with Example 2, the embodiment and Comparative Example 1 have smaller loss and larger grinding ratio, which shows that the binder obtained after the resin and metal are compounded not only has good self-sharpening property but also is easy to dress. The composite binder is mixed with diamond to prepare the abrasive tool, in which the metal powder plays the role of structural support in the abrasive tool, which ensures that the abrasive tool has the necessary strength and hardness. The addition of polymer resin enhances the elasticity and self-sharpening ability of the abrasive tool, which enables the abrasive tool to better maintain sharpness during work, so the grinding performance is better.

[0069] The diamine monomer in Example 2 has a difluorene structure. Since difluorene has a special rigid in-plane biphenyl structure, it is more stable than a diphenyl ring structure. The diamine monomer in Example 3 has a spirobifluorene structure. Spirobifluorene compounds have a special three-dimensional orthogonal structure. There is a spiro conjugation effect inside spirobifluorene, which helps to improve the rigidity of the molecule and leads to higher strength. Therefore, the abrasive tool in Example 3 has less loss and a larger grinding ratio.

[0070] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A diamond-containing alloy abrasive material, characterized in that: The method comprises the following raw materials in parts by weight: 70 to 90 parts of a composite binder, 10 to 20 parts of diamond and 1 to 5 parts of an adhesive wetting agent; The preparation method of the composite binder comprises the following steps: S1: mixing a diamine monomer with 3,4'-diaminodiphenyl ether, 4,4-diisobenzofuran-1,1,3,3-tetraketone, and 4-phenylethynylphthalic anhydride in a solvent, adding toluene, raising the temperature, polymerizing under an inert atmosphere, and performing post-treatment after the reaction to obtain a polymer; S2. Evenly mix the polymer resin and the metal powder to obtain a composite binder.

2. The diamond-containing alloy abrasive material according to claim 1, characterized in that: The bonding and wetting agent is paraffin or glycerin.

3. The diamond-containing alloy abrasive material according to claim 1, characterized in that: The preparation method of the composite binder comprises the following steps: S1: adding diamine monomer and 3,4'-diaminodiphenyl ether to 8 to 15 times the volume of N-methylpyrrolidone, mixing evenly, adding 4,4-diisobenzofuran-1,1,3,3-tetraketone and 4-phenylethynylphthalic anhydride, adding toluene, heating, polymerizing under an inert atmosphere, cooling to room temperature after the reaction, pouring into 5 to 10 times the volume of ethanol, precipitating, filtering, washing the residue with ethanol and water, drying, and crushing to obtain a polymer resin; S2. Evenly mix the polymer resin and the metal powder in a mass ratio of 1:5 to 6 to obtain a composite binder.

4. The diamond-containing alloy abrasive material according to claim 3, characterized in that: The molar ratio of the diamine monomer to 3,4'-diaminodiphenyl ether, 4,4-diisobenzofuran-1,1,3,3-tetraketone and 4-phenylethynylphthalic anhydride is 1-2:0.1-1:1-2:1-2.

5.

5. The diamond-containing alloy abrasive material according to claim 3, characterized in that: The temperature range of the heating is 160-200° C.; the polymerization time is 6-10 hours; and the volume of toluene is 0.2-0.4 times that of N-methylpyrrolidone.

6. The diamond-containing alloy abrasive material according to claim 3, characterized in that: The metal powder is a mixture of two or more of copper, cobalt, iron, tin and zinc.

7. The method for preparing a diamond-containing alloy abrasive material according to any one of claims 1 to 6, characterized in that: The steps include: The composite binder, diamond and adhesive wetting agent are mixed by ball milling, pre-pressed into a shape, and then sintered and trimmed to obtain the diamond-containing abrasive tool material.

8. The method for preparing a diamond-containing alloy abrasive material according to claim 7, characterized in that: The ball milling time is 3 to 6 hours.

9. The method for preparing a diamond-containing alloy abrasive material according to claim 7, characterized in that: The pre-pressing pressure is 10-30 MPa.

10. The method for preparing a diamond-containing alloy abrasive material according to claim 7, characterized in that: The sintering temperature is 400-800° C., the pressure is 30-50 MPa, and the sintering time is 2-4 hours.