Composite grinding wheel for grinding double end faces of powder metallurgy product and preparation method of composite grinding wheel

Abstract

The invention discloses a composite grinding wheel for grinding double end faces of a powder metallurgy product and a preparation method of the composite grinding wheel, the composite grinding wheel comprises a base body and grinding material segments, the grinding material segments are ceramic bond grinding blocks and resin bond grinding blocks which are alternately and evenly arranged, and the ceramic bond grinding blocks are composed of compound ceramic bond, diamond, ceramic corundum, pore forming agents and auxiliary materials; the resin binder grinding block is composed of a compound resin binder, diamond, silicon carbide, a pore-forming agent and auxiliary materials. The composite grinding wheel is good in sharpness, good in grinding grain, efficient in grinding and good in polishing and grinding effect, the problem that powder metallurgy products are scratched in the grinding process is avoided, the surface grinding quality of workpieces is greatly improved, the roughness is reduced, the grinding blocks keep the efficient grinding state, the finishing frequency is reduced, and the grinding efficiency is improved. The durability of the grinding wheel is improved.

Description

Technical Field

[0001] The invention relates to a resin ceramic superhard composite grinding wheel for grinding double end surfaces of powder metallurgy products, and in particular to a preparation method of the resin ceramic superhard composite grinding wheel for grinding double end surfaces of powder metallurgy products. Background Art

[0002] As an advanced material preparation technology, powder metallurgy has shown unique advantages in a variety of industrial applications and plays a vital role in the development of new materials. Powder metallurgy has unique chemical composition and mechanical and physical properties, which cannot be obtained by traditional melting and casting methods. Powder metallurgy technology can be used to directly produce porous, semi-dense or fully dense materials and products. If these powder metallurgy products want to achieve a good surface roughness, they need to be processed by grinding. However, the characteristics of powder metallurgy products make it easy to scratch during the grinding process, which affects the surface quality of the workpiece and cannot meet the product quality requirements. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a high-performance grinding wheel for end surface grinding of powder metallurgy workpieces, which is a resin ceramic superhard composite grinding wheel. This grinding wheel can avoid scratches on powder metallurgy products during grinding and maintain an efficient grinding state.

[0004] To achieve the above object, the present invention provides the following technical solutions: A composite grinding wheel for double-end surface grinding of powder metallurgy products comprises a base body and abrasive segments. The abrasive segments comprise ceramic bond grinding blocks and resin bond grinding blocks.

[0005] In the present invention, the abrasive segments are composed of ceramic bond grinding blocks and resin bond grinding blocks; preferably, the ceramic bond grinding blocks and resin bond grinding blocks are arranged alternately, and more preferably, they are arranged alternately and evenly. The alternating arrangement or alternating and even arrangement refers to the spacing distribution of the ceramic bond grinding blocks and the resin bond grinding blocks. The specific arrangement is designed according to actual production needs, such as radial arrangement from the center to the edge of the substrate, wherein a single circle of ceramic bond grinding blocks and a single circle of resin bond grinding blocks are arranged at intervals.

[0006] In the present invention, the raw materials for preparing the ceramic bond grinding block are as follows: Diamond Residue Compound ceramic binder 10~40% Ceramic corundum 5~40% Pore ​​forming agent 1~20% Wetting agent 2-15%.

[0007] The raw materials for preparing the resin bond grinding block are as follows: Diamond Residue Compound resin binder 10~50% Silicon carbide 5~40% Pore ​​forming agent 1~20% Chromium oxide 1~10% Wetting agent 2-15%.

[0008] The grinding wheel base of the present invention has a threaded mounting hole on one side and an abrasive segment bonded to the other side; the abrasive segment is partially a ceramic bond grinding block and partially a resin bond grinding block, the main abrasive is diamond, and the auxiliary abrasive is ceramic corundum or silicon carbide; the ceramic bond grinding blocks and the resin bond grinding blocks are alternately and evenly arranged.

[0009] Preferred: The vitrified bond grinding block is prepared from the following raw materials in volume fraction: Diamond Residue Compound ceramic binder 10~35% Ceramic corundum 20~30% Pore ​​forming agent 3~18% Wetting agent 3-15%.

[0010] The resin bond grinding block is prepared from the following raw materials in volume fraction: Diamond Residue Compound resin binder 20-40%; Silicon carbide 5-35%; Pore ​​forming agent 5~12% Chromium oxide 1~6% Wetting agent 2-8%.

[0011] Further preferred: The vitrified bond grinding block is prepared from the following raw materials in volume fraction: Diamond Residue Compound ceramic binder 10~30% Ceramic corundum 20~30% Pore ​​forming agent 3~10% Wetting agent 3-8%.

[0012] The resin bond grinding block is prepared from the following raw materials in volume fraction: Diamond Residue Compound resin binder 22-30%; Silicon carbide 10-20%; Pore ​​forming agent 8~12% Chromium oxide 2~5% Wetting agent 2-6%.

[0013] In the present invention, the specific raw materials and substrates are existing products, for example, diamond is a regularly shaped shaped material with a regular tetrahedron or hexahedron appearance; the substrate is one of a steel substrate, a cast iron substrate, an aluminum substrate and an aluminum alloy substrate, and the outer diameter of the substrate is 300 to 1600 mm; it can meet the conventional requirements of grinding wheels.

[0014] In the present invention, the composite ceramic binder includes SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives, and the additives are one or more of K2O, P2O5, TiO2 and B2O3.

[0015] Preferably, by volume percentage, the ratio of SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives is as follows: SiO2 10~70% Al2O3 3~30% Li2O 2~30% CaO 1~20% Bi2O3 1~15% Additive balance.

[0016] Preferably, by volume percentage, the ratio of SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives is as follows: SiO2 20~60% Al2O3 10~30% Li2O 10~20% CaO 5~15% Bi2O3 5~15% Additive balance.

[0017] Preferably, by volume percentage, the ratio of SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives is as follows: SiO2 30~50% Al2O3 15~25% Li2O 12~18% CaO 7~13% Bi2O3 8~12% Additive balance.

[0018] Preferably, the size of the ceramic corundum is not greater than 0.1 μm, for example, the size of the ceramic corundum is 0.01 to 0.1 μm, preferably 0.05 to 0.1 μm.

[0019] Preferably, the pore-forming agent is one or more of jujube shell, urea sphere or polyethylene glycol.

[0020] In the present invention, the composite resin binder comprises phenolic resin powder, liquid phenolic resin, polyurethane and additives, wherein the additives are one or more of sodium fluorosilicate, ethylene glycol and sodium hexafluoroaluminate. Preferably, the polyurethane comprises silane-modified polyurethane.

[0021] In the present invention, the resin binder has the following components in volume percentage: Phenolic resin powder 40~90% Liquid phenolic resin 5~30% Silane modified polyurethane 5~30% Additive balance.

[0022] Preferably, the resin binder has the following components in volume percentage: Phenolic resin powder 40~70% Liquid phenolic resin 10~30% Silane modified polyurethane 5~20% Additive balance.

[0023] Preferably, the resin binder has the following components in volume percentage: Phenolic resin powder 50~70% Liquid phenolic resin 15~25% Silane modified polyurethane 10~20% Additive balance.

[0024] In the present invention, the pore former is a chloride; preferably, the pore former is one or more of potassium chloride, calcium chloride or ammonium chloride.

[0025] Preferably, the wetting agent is one or more of phenolic resin liquid, epoxy resin liquid, polyvinyl alcohol or sodium silicate.

[0026] The present invention discloses a method for preparing the composite grinding wheel for double-end surface grinding of the powder metallurgy product, comprising the following steps: (1) Diamond, composite vitrified binder, vitrified corundum, pore former and wetting agent are mixed, then cold pressed and sintered to obtain a vitrified binder grinding block; (2) diamond, compound resin bond, silicon carbide, chromium oxide, pore former and wetting agent are mixed and then hot pressed to obtain a resin bond abrasive block; (3) The ceramic bond grinding block and the resin bond grinding block are respectively compounded with the matrix to obtain the composite grinding wheel for double-end surface grinding of the above-mentioned powder metallurgy product.

[0027] In the present invention, the ceramic bond grinding block and the resin bond grinding block are respectively compounded with the substrate as a conventional technology. A bonding method can be adopted, such as using commercially available epoxy resin glue to bond the abrasive segment to the substrate, and curing at room temperature to obtain the above-mentioned composite grinding wheel for double-end surface grinding of powder metallurgy products.

[0028] Furthermore, the ceramic bond grinding block and the resin bond grinding block are respectively compounded with the matrix, and then filled with glue and machined to obtain the composite grinding wheel for double-end surface grinding of the powder metallurgy product; these steps are all conventional technologies.

[0029] The invention discloses application of the composite grinding wheel for double-end surface grinding of powder metallurgy products in preparing grinding tools.

[0030] The invention discloses application of the composite grinding wheel for double-end surface grinding of powder metallurgy products in preparing powder metallurgy grinding tools.

[0031] The invention discloses a method for processing powder metallurgy, which uses the composite grinding wheel for double-end surface grinding of the powder metallurgy product for processing.

[0032] Beneficial effects of the present invention: First, the resin ceramic superhard composite grinding wheel grinding blocks selected by the present invention are ceramic bond grinding blocks and resin bond grinding blocks. The two grinding blocks are alternately and evenly arranged, have the performance of efficient grinding and the effect of polishing, can greatly improve the surface quality of the workpiece, and avoid the occurrence of scratches on the surface of the powder metallurgy workpiece. Secondly, the composite ceramic binder selected by the ceramic bond grinding block of the present invention is a microcrystalline ceramic binder system, which has the characteristics of high efficiency and high durability. With the pore-forming agent, the prepared ceramic grinding block has uniform pore structure and high grinding efficiency; the resin bond grinding block has a good polishing and grinding effect, which can greatly improve the surface grinding quality of the workpiece and reduce the roughness. Thirdly, the pore-forming agent and pore-forming agent selected by the present invention have excellent pore-forming effects, which can keep the ceramic bond grinding block and the resin bond grinding block in a state of efficient grinding, reduce the frequency of dressing, and improve the durability of the grinding wheel, especially play the technical effect of the synergy of the ceramic bond grinding block and the resin bond grinding block. Processing and production have confirmed that the above scheme avoids the problem of surface scratches during the grinding of powder metallurgy workpieces, and also improves the grinding efficiency; the resin ceramic superhard composite grinding wheel using the above scheme also has the above advantages during the grinding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the side view of the structure of a resin ceramic superhard composite grinding wheel for double-end surface grinding of powder metallurgy products according to an embodiment of the present invention.

[0034] Figure 2This is a schematic diagram of the top view of the structure of a resin-ceramic superhard composite grinding wheel for double-end surface grinding of powder metallurgy products according to an embodiment of the present invention; wherein, the wheel comprises a base 1, an abrasive segment 2, a ceramic abrasive segment 3, and a resin abrasive segment 4.

[0035] Figure 3 This is a flow chart of the preparation method of the resin ceramic superhard composite grinding wheel for double-end grinding of powder metallurgy products in the embodiment.

[0036] Figure 4 This is the surface of the workpiece after being processed by the composite grinding wheel in Example 1.

[0037] Figure 5 This is the surface of the workpiece after being processed by the composite grinding wheel in Example 2.

[0038] Figure 6 This is the surface of the workpiece after being processed by the composite grinding wheel in Example 3.

[0039] Figure 7 This is the surface of the workpiece after grinding wheel processing in Comparative Example 1.

[0040] Figure 8 This is the surface of the workpiece after grinding wheel processing in Comparative Example 2.

[0041] Fig. 9 This is the surface of the workpiece after grinding wheel processing in Comparative Example 5. DETAILED DESCRIPTION

[0042] The invention discloses a resin ceramic superhard composite grinding wheel for double-end surface grinding of powder metallurgy products, comprising a matrix and abrasive segments, wherein a part of the abrasive segments is a ceramic bond grinding block and a part is a resin bond grinding block, the main abrasive is diamond, and the auxiliary abrasive is ceramic corundum or silicon carbide; the ceramic bond grinding blocks and the resin bond grinding blocks are alternately and evenly arranged.

[0043] The present invention discloses a method for preparing the composite grinding wheel for double-end surface grinding of the powder metallurgy product, comprising the following steps: (1) Preparation of vitrified bond abrasive block mixture: diamond abrasive, vitrified bond, vitrified corundum and pore-forming agent are placed in a mixer and stirred and mixed, then a wetting agent is added and the mixture is continued to be mixed for 20 to 120 minutes. After being sieved through a 40 to 120 mesh sieve, the mixture is formed and placed in a container for later use; (2) Resin bond abrasive block mixing: Place diamond abrasive, resin bond, silicon carbide, chromium oxide, and pore-forming agent in a mixer and stir and mix. Then add a wetting agent and continue mixing for 20 to 120 minutes. After passing through a 40 to 120 mesh sieve, a mixture is formed and placed in a container for later use. (3) Ceramic bond abrasive segment fixed mold forming, the mixed material is put into a conventional mold, added evenly, scraped flat, placed on a press operating table and flattened to form a ceramic bond abrasive segment blank; (4) sintering the ceramic bond abrasive segment, placing the ceramic bond abrasive segment green body in a sintering furnace, heating the green body from room temperature to 450-600° C. over 1-3 hours, keeping the temperature for 0.5-1 hour, then heating the green body to 650-850° C. over 0.5-1 hour, keeping the temperature for 0.5-1 hour, and naturally cooling the green body to room temperature to obtain the ceramic bond abrasive segment; (5) Hot pressing the resin bond abrasive segment, putting the mixed material into a conventional mold, adding it evenly, scraping it flat, and heating it to 90±2°C at a heating rate of ≤3°C / min (e.g. 0.5-3°C / min); then heating it to 130±2°C at a heating rate of ≤2°C / min (e.g. 0.5-2°C / min), and keeping it warm for 0.5-2 hours; then heating it to 180±2°C at a heating rate of ≤2°C / min (e.g. 0.5-2°C / min), and keeping it warm for 3-10 hours; cooling it naturally to room temperature, and obtaining the resin bond abrasive segment; (6) bonding: using commercially available epoxy resin glue to bond the abrasive segment to the substrate, curing at room temperature for more than 12 hours, and operating according to the instructions to obtain a grinding wheel blank; (7) Filling: Use commercially available epoxy resin liquid and matching curing agent to fill the gaps between the above grinding wheel blanks, and cure them at room temperature for more than 12 hours. Follow the instructions to obtain a semi-finished grinding wheel; (8) Processing: processing the semi-finished grinding wheel on a CNC grinding machine to a required shape and size, thereby obtaining a resin-ceramic superhard composite grinding wheel for double-end surface grinding of powder metallurgy products.

[0044] (9) Inspection and storage: The resin ceramic super-hard composite grinding wheels for double-end grinding of powder metallurgy products mentioned above shall be put into storage for standby use after passing the inspection.

[0045] In the above technical scheme, except for the formula, the specific preparation operations of each step are conventional techniques.

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] The raw materials used in the present invention are existing commercial products that meet the conventional requirements of grinding wheels. The specific preparation operations and performance tests are all conventional technologies; the size of the ceramic corundum is 0.05-0.1 μm, the phenolic resin powder is 2123, the phenolic resin liquid is 2124, the silane-modified polyurethane is SK800S, and the particle size of the diamond is 325 / 400#.

[0048] Synthesis example By volume percentage, the proportions of SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives are as follows: SiO2 40% Al2O3 20% Li2O 15% CaO 10% Bi2O3 10% Additive 5% According to the conventional method, SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives are melted at 1400°C, then cooled and crushed to obtain a composite ceramic binder.

[0049] The resin binder is composed of the following components in volume percentage: Phenolic resin powder 60% Liquid phenolic resin 20% Silane modified polyurethane 15% Additive (ethylene glycol) 5% The phenolic resin powder, the phenolic resin liquid, the silane-modified polyurethane and the additives are conventionally mixed to obtain the compound resin binder.

[0050] Example 1 See also Figure 1 and Figure 2 A resin ceramic superhard composite grinding wheel for double-end grinding of powder metallurgy products comprises a substrate 1 and an abrasive segment 2, wherein the abrasive segment consists of a ceramic abrasive segment 3 and a resin abrasive segment 4, which are radially arranged from the center to the edge of the substrate, wherein a single-circle ceramic bond grinding block and a single-circle resin bond grinding block are arranged at intervals.

[0051] Figure 3 This is a flow chart of the preparation method of the resin ceramic superhard composite grinding wheel for double-end grinding of powder metallurgy products in the embodiment.

[0052] Specifically, the ceramic abrasive segment includes the following components in volume percentage: Diamond Residue Compound ceramic binder 20% Ceramic corundum 25% Pore ​​forming agent 5% Wetting agent 5% The resin abrasive segments are prepared from the following raw materials in volume fractions: Diamond Residue Compound resin binder 28% Silicon carbide 15% Pore ​​forming agent 10% Chromium oxide 3% Wetting agent 4% The substrate 1 is a steel base, and the composite ceramic binder includes SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives, wherein the additives are equal volumes of K2O and TiO2; the pore-forming agent is jujube shell, the pore-forming agent is potassium chloride, and the wetting agent is epoxy resin liquid.

[0053] The preparation steps of the above-mentioned grinding wheel are as follows: The first step is to mix the ceramic abrasive segments. The diamond abrasive, the composite ceramic binder and the ceramic corundum are placed in a mixer for pre-stirring and mixing. Then, the epoxy resin liquid E44 and the pore-forming agent are added and the mixture is continued for 2 hours. After passing through an 80-mesh sieve, the mixture is formed and placed in a container for standby use. The second step is to mix the resin abrasive blocks. The diamond abrasive, resin binder, silicon carbide and chromium oxide are placed in a mixer for pre-stirring and mixing. Then 4% of a wetting agent and a pore-forming agent are added. The mixture is mixed for 60 minutes. After passing through an 80-mesh sieve, the mixture is formed and placed in a container for standby use. The third step is to form the ceramic bond abrasive segment by fixed die, putting the mixed material into the corresponding mold, adding it evenly, scraping it flat, and placing it on a 60-ton press operating table to flatten it to form a ceramic bond abrasive segment blank; The fourth step is sintering the ceramic bond abrasive segment. The ceramic bond abrasive segment green body is placed in a sintering furnace, and the temperature is raised from room temperature to 550° C. in 2 hours, and kept at this temperature for 0.5 hours. The temperature is then raised to 750° C. in 1 hour, and kept at this temperature for 1 hour, and then naturally cooled to room temperature to obtain the ceramic bond abrasive segment. The fifth step is to hot-press the resin bond abrasive segment. The mixture is put into the corresponding mold, evenly added, scraped and leveled, and the temperature is raised to 90±2°C at a heating rate of 2°C / min; then raised to 130±2°C at a heating rate of 1.5°C / min, and kept warm for 1 hour; then raised to 180±2°C at a heating rate of 1°C / min, and kept warm for 5 hours; naturally cooled to room temperature to obtain the resin bond abrasive segment.

[0054] The following is the existing technology: Step 6: bonding: using commercially available epoxy resin glue to bond the abrasive segment to the substrate, and curing at room temperature for 12 hours to obtain a grinding wheel blank; Step 7: Filling: Use commercially available epoxy resin liquid and matching curing agent to fill the gaps between the above grinding wheel blanks, and cure them at room temperature for 12 hours to obtain a semi-finished grinding wheel; The eighth step is processing, processing the semi-finished grinding wheel on a CNC grinding machine to a required shape and size, thereby obtaining a resin ceramic superhard composite grinding wheel for double-end surface grinding of powder metallurgy products.

[0055] The ninth step is inspection and storage. After the above-mentioned resin ceramic super-hard composite grinding wheel for double-end surface grinding of powder metallurgy products passes the inspection, it will be stored for standby use.

[0056] Example 2 The pore-forming agent is urea balls, the pore-forming agent is calcium chloride, the wetting agent is phenolic resin liquid, and the rest is the same as in Example 1.

[0057] Comparative Example 1, conventional ceramic bond superhard grinding wheel on the market.

[0058] Comparative Example 2, conventional resin bond superhard grinding wheel on the market.

[0059] In Comparative Example 3, the silicon carbide in the resin abrasive segment is replaced by ceramic corundum, and the rest is the same as in Example 1.

[0060] The embodiments and comparative examples were subjected to grinding comparison tests according to the same size of double-end grinding wheel specifications and working conditions. The diameter of the grinding wheel was 700 mm, the inner hole diameter was 300 mm, the base thickness was 50 mm, the working layer thickness was 8 mm, the workpiece was the engine outer rotor, and the material was iron-based powder metallurgy. The test results are shown in Table 1.

[0061] Table 1 Test results of different embodiments and comparative examples

[0062] It can be seen from the above test comparison results that there are currently no composite grinding wheels for powder metallurgy products in production, and the two mainstream grinding wheels each have obvious defects. The resin ceramic superhard composite grinding wheel for double-end surface grinding of powder metallurgy products of the present invention solves the scratch problem generated during the end surface grinding of powder metallurgy workpieces and maintains a high-efficiency grinding state. The number of workpieces that can be ground after one dressing is more than three times that of conventional ceramic bond superhard grinding wheels or resin bond superhard grinding wheels.

[0063] Example 3 In the composite ceramic binder, the additives are equal volumes of K2O and B2O3; the pore-forming agent is jujube shell, the pore-forming agent is ammonium chloride, the wetting agent is polyvinyl alcohol, and the rest is the same as in Example 1.

[0064] See also Figure 4 , Figure 5 as well as Figure 6 , which is the surface of the workpiece after being processed by the composite grinding wheel in Example 1, Example 2 and Example 3, without any scratches.

[0065] See also Figure 7 as well as Figure 8 , which are the surfaces of the workpieces after grinding wheel processing in Comparative Example 1 and Comparative Example 2, and are obviously scratched.

[0066] Example 4 The ceramic abrasive segment includes the following components in volume percentage: Diamond Residue Compound ceramic binder 22% Ceramic corundum 28% Pore ​​forming agent 6% Wetting agent 4% The resin abrasive segments are prepared from the following raw materials in volume fractions: Diamond Residue Compound resin binder 30% Silicon carbide 16% Pore ​​former 11% Chromium oxide 4% Wetting agent 4% The rest is the same as in Example 1 to prepare a composite grinding wheel.

[0067] Example 5 The ceramic abrasive segment includes the following components in volume percentage: Diamond Residue Compound ceramic binder 18% Ceramic corundum 24% Pore ​​forming agent 4.5% Wetting agent 5% The resin abrasive segments are prepared from the following raw materials in volume fractions: Diamond Residue Compound resin binder 27% Silicon carbide 14% Pore ​​former 11% Chromium oxide 4% Wetting agent 4% The rest is the same as in Example 1 to prepare a composite grinding wheel.

[0068] Comparative Example 4 Diamond was replaced by cubic boron nitride, and the rest was the same as in Example 1. When the prepared composite grinding wheel was used, the average grinding time for a single piece was 7s.

[0069] Comparative Example 5 The additives were omitted in the composite vitrified binder, and the rest was the same as in Example 1 to prepare the composite grinding wheel. The application effect was poor and there was a small amount of scratching. Fig. 9 .

[0070] Comparative Example 6 Chromium oxide was omitted, and the rest was the same as in Example 1 to prepare a composite grinding wheel. When used, the polishing effect was not as good as that of the existing grinding wheel.

[0071] Comparative Example 7 Polyurethane was omitted from the compound resin binder, and the rest was the same as in Example 1 to prepare a composite grinding wheel, but the application effect was poor and there was a small amount of scratching.

[0072] The present invention discloses a resin-ceramic super-hard composite grinding wheel for double-end grinding of powder metallurgy products, including a matrix and abrasive segments, wherein the abrasive segments are ceramic bond grinding blocks and resin bond grinding blocks, the ceramic bond grinding blocks are composed of a compound ceramic bond, diamond, ceramic corundum, a pore-forming agent and auxiliary materials; the resin bond grinding blocks are composed of a compound resin bond, diamond, silicon carbide, a pore-forming agent and auxiliary materials. The ceramic bond grinding blocks and the resin bond grinding blocks are arranged alternately and evenly. The present invention comprehensively utilizes the characteristics of good sharpness of ceramic bond grinding blocks and good grinding lines of resin bond grinding blocks, and arranges the two types of grinding blocks alternately and evenly, which can give full play to the advantages of ceramic bond grinding blocks and resin bond grinding blocks, especially embodies the synergistic effect of the two, and avoids the problem of scratches on powder metallurgy products during the grinding process. Secondly, the ceramic binder and resin binder selected in the present invention are both compound binder systems, which can keep the ceramic binder grinding block sharp and ensure efficient grinding; the resin binder grinding block has good polishing and grinding effect, which can greatly improve the surface grinding quality of the workpiece and reduce the roughness. Thirdly, the pore-forming agent and pore-forming agent selected in the present invention have excellent pore-forming effect, which can keep the ceramic binder grinding block and the resin binder grinding block in a state of efficient grinding, reduce the frequency of dressing, and improve the durability of the grinding wheel. In short, the resin ceramic superhard composite grinding wheel for double-end grinding of powder metallurgy products disclosed in the present invention has the synergistic processing effect of ceramics and resins, and unexpectedly solves the problem that it is difficult for existing grinding tools to process powder metallurgy workpieces.

Claims

1. A composite grinding wheel for double-end grinding of powder metallurgy products, comprising a base and an abrasive segment, wherein the abrasive segment comprises a ceramic bond grinding block and a resin bond grinding block.

2. The composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 1, characterized in that: The ceramic bond grinding blocks and the resin bond grinding blocks are arranged alternately.

3. The composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 1, characterized in that: The raw materials for the preparation of vitrified bond grinding blocks are as follows: Diamond Residue Compound ceramic binder 10~40% Ceramic corundum 5~40% Pore ​​forming agent 1~20% Wetting agent 2-15%; The raw materials for preparing the resin bond grinding block are as follows: Diamond Residue Compound resin binder 10~50% Silicon carbide 5~40% Pore ​​forming agent 1~20% Chromium oxide 1~10% Wetting agent 2-15%.

4. The composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 3, characterized in that: The vitrified bond grinding block is prepared from the following raw materials in volume fraction: Diamond Residue Compound ceramic binder 10~35% Ceramic corundum 20~30% Pore ​​forming agent 3~18% Wetting agent 3-15%; The resin bond grinding block is prepared from the following raw materials in volume fraction: Diamond Residue Compound resin binder 20-40%; Silicon carbide 5-35%; Pore ​​forming agent 5~12% Chromium oxide 1~6% Wetting agent 2-8%.

5. The composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 3, characterized in that: The composite ceramic binder includes SiO2, Al2O3, Li2O, CaO, Bi2O3 and additives, wherein the additives are one or more of K2O, P2O5, TiO2 and B2O3; the size of the ceramic corundum is not greater than 0.1 μm; and the pore-forming agent is one or more of jujube shell, urea balls or polyethylene glycol.

6. The composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 3, characterized in that: The composite resin binder includes phenolic resin powder, phenolic resin liquid, polyurethane and additives, wherein the additive is one or more of sodium fluorosilicate, ethylene glycol and sodium hexafluoroaluminate; the pore former is chloride; and the wetting agent is one or more of phenolic resin liquid, epoxy resin liquid, polyvinyl alcohol or sodium silicate.

7. The method for preparing the composite grinding wheel for double-end grinding of powder metallurgy products according to claim 1 comprises the following steps: (1) Diamond, composite vitrified binder, vitrified corundum, pore former and wetting agent are mixed, then cold pressed and sintered to obtain a vitrified binder grinding block; (2) diamond, compound resin bond, silicon carbide, chromium oxide, pore former and wetting agent are mixed, and then hot pressed to obtain a resin bond abrasive block; (3) The ceramic bond grinding block and the resin bond grinding block are respectively compounded with the matrix to obtain the composite grinding wheel for double-end surface grinding of the above-mentioned powder metallurgy product.

8. Use of the composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 1 in the preparation of grinding tools.

9. Use of the composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 1 in the preparation of powder metallurgy abrasive tools.

10. A method for processing powder metallurgy, using the composite grinding wheel for double-end surface grinding of powder metallurgy products according to claim 1 for processing.

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