Precise TPI-copper-based metal composite binder grinding tool and preparation method thereof

Abstract

The invention discloses a precise TPI-copper-based metal composite binding agent grinding tool and a preparation method thereof. The grinding tool comprises the following components in parts by weight: 100 parts of a grinding material, 10-30 parts of a resin binding agent, 60-90 parts of a copper-based metal binding agent and 2 parts of a wetting agent. The thermoplastic polyimide TPI is added into the formula, a large number of ether bonds, alkyl groups and rigid group benzene rings are introduced into the molecular structure of the TPI, the processability of the TPI is improved, meanwhile, the defect of insufficient heat resistance is overcome, and therefore the TPI resin binding agent better in temperature matching performance with a copper-based metal binding agent is obtained. In the composite superhard grinding tool prepared from the copper-based metal binding agent and the TPI resin binding agent, the existence of the metal binding agent plays a role in supporting a framework, and the strength and hardness of the grinding tool are guaranteed; the TPI resin binding agent increases the elasticity and the self-sharpening property of the grinding tool, so that the self-sharpening property of the grinding tool in the working process is improved, and better workpiece processing surface quality can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of abrasive materials, and particularly to a precision TPI - copper - based metal composite binder abrasive tool and a preparation method thereof. Background Art

[0002] Traditional resin - bonded super - hard grinding wheels used for processing silicon wafers have defects such as short service life, low processing efficiency, poor heat resistance, easy oxidation and decomposition, and poor holding force for diamond; metal - bonded super - hard grinding wheels have too high binder strength, resulting in poor self - sharpening of the overall super - hard grinding wheel, difficult dressing, easy clogging, and are partially applicable to the rough grinding process of wafers; although traditional ceramic - bonded super - hard grinding wheels have advantages such as high temperature resistance, high hardness, and high efficiency, their high - hardness and brittle characteristics easily cause residual stress in wafers, resulting in low processing surface quality.

[0003] Thus, facing the processing requirements of SiC wafers without subsurface damage such as grinding marks, micro - cracks, pits, and amorphous, traditional super - hard abrasive tools can no longer meet the current extreme processing requirements of wafers. Therefore, a composite binder (metal / resin) combines the advantages of the two binders, has higher wear resistance, better cutting performance, better surface uniformity, higher life and other comprehensive properties, and has a very wide application prospect in the fields of thinning grinding wheels, ultra - thin grinding wheels, refractory materials, photovoltaic power generation, etc. Due to its strong durability, good self - sharpening, small deformation, and excellent processing quality, it shows excellent performance in processing fine ceramic components. Super - hard abrasive tools are moving from the era of "single - type" binders to the era of "composite - type" binders, and composite - binder diamond grinding wheels show extremely broad application potential in the fine thinning processing of third - generation semiconductor materials.

[0004] Therefore, it is necessary to propose a preparation method of a precision TPI - copper - based metal composite binder abrasive tool to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a precision TPI - copper - based metal composite binder abrasive tool and a preparation method thereof in view of the above - mentioned deficiencies in the prior art.

[0006] To solve the above - mentioned technical problems, the technical solution adopted by the present invention is: In the first aspect of the present invention, a precision TPI - copper - based metal composite binder abrasive tool is provided, which includes the following components by weight: 100 parts of abrasive, 10 - 30 parts of resin binder, 60 - 90 parts of copper - based metal binder, and 2 parts of wetting agent;

[0007] Among them, the resin binder is thermoplastic polyimide, and the copper - based metal binder includes 70wt% - 80wt% of Cu, 12wt% - 20wt% of Sn, and 6wt% - 8wt% of P.

[0008] Preferably, the thermoplastic polyimide is prepared by the following method:

[0009] 1) Add 2,2-bis[4-(4-aminophenoxy)phenyl] (BAPP) and 4,4'-diaminodiphenyl ether (ODA) into a dry four-necked flask equipped with magnetic stirring, condenser, constant pressure dropping funnel, thermometer and N2 interface, add N,N-dimethylacetamide (DMAC) solution, and stir and disperse in an ice-water bath until completely dissolved;

[0010] 2) Add pyromellitic dianhydride (PMDA) into the DMAC solution, mix evenly, drop the obtained solution into the product obtained in step 1), and finally add DMAC solution to adjust the solid content of the obtained mixture to 5-20%, and react at 0-5 °C for 3-12 h to obtain a polyamic acid (PAA) solution;

[0011] 3) Pour the PAA solution into deionized water for precipitation, filter by suction, continue to rinse and filter with deionized water, then rinse with ethanol, dry to constant weight under vacuum, grind to obtain a solid powder, and finally perform thermal imidization on the solid powder in an N2 atmosphere to obtain a thermoplastic polyimide.

[0012] Preferably, the thermoplastic polyimide is prepared by the following method:

[0013] 1) Add 2,2-bis[4-(4-aminophenoxy)phenyl] (BAPP) and 4,4'-diaminodiphenyl ether (ODA) into a dry four-necked flask equipped with magnetic stirring, condenser, constant pressure dropping funnel, thermometer and N2 interface, add N,N-dimethylacetamide (DMAC) solution, and stir and disperse in an ice-water bath until completely dissolved;

[0014] 2) Add pyromellitic dianhydride (PMDA) into the DMAC solution, mix evenly, drop the obtained solution into the product obtained in step 1) at a uniform speed within 30 min, and finally add DMAC solution to adjust the solid content of the obtained mixture to 10%, and react at 0-5 °C for 6 h to obtain a polyamic acid (PAA) solution;

[0015] 3) Pour the PAA solution into deionized water for precipitation, filter by suction, continue to rinse and filter with deionized water, then rinse with ethanol, dry to constant weight under vacuum, grind to obtain a solid powder, and finally perform thermal imidization on the solid powder in an N2 atmosphere to obtain a thermoplastic polyimide. The thermal imidization process is: rise from room temperature to 300 °C in 120 min, hold for 1 h, and cool to room temperature.

[0016] Preferably, the abrasive is a diamond abrasive with a particle size of 400-800 mesh.

[0017] Preferably, the wetting agent is a polyvinyl alcohol solution.

[0018] Preferably, the wetting agent is a polyvinyl alcohol solution with a mass concentration of 3 wt%.

[0019] Preferably, the wetting agent is prepared by the following method:

[0020] Mix polyvinyl alcohol particles with distilled water, place them in a constant temperature water bath, heat and stir at 98 °C for 3 h, and cool to room temperature with cold water to obtain a polyvinyl alcohol solution, which is the wetting agent.

[0021] In the second aspect of the present invention, a method for preparing the precision TPI - copper - based metal composite binder abrasive tool as described above is provided, including the following steps:

[0022] S1. Mixing: Place the resin binder and the copper - based metal binder in a ball mill and mix them evenly for 15 - 60 min, pour out and screen, then place them in a three - dimensional mixer with the abrasive and mix for 10 - 40 min, and finally add the wetting agent and mix for 2 - 10 min to obtain the molding material.

[0023] S2. Pour the molding material into a mold, carry out vacuum hot - press sintering, and demold to make the precision TPI - copper - based metal composite binder abrasive tool.

[0024] Preferably, step S1 is specifically: Place the resin binder and the copper - based metal binder in a ball mill and mix them evenly for 30 min, pour out and screen through a 300 - mesh sieve, then place them in a three - dimensional mixer with the abrasive and mix for 20 min, and finally add the wetting agent and mix for 5 min to obtain the molding material.

[0025] Preferably, step S2 is specifically:

[0026] Pour the molding material into a graphite mold, carry out vacuum hot - press sintering, set the pressure to 3.0 MPa, and the sintering curve is: heat from room temperature to 200 °C in 1 min and start vacuum pumping, heat from 200 °C to 440 °C in 3 min and then hold the pressure and temperature for 6 min, cool from 440 °C to 100 °C in 5 min, and cool to room temperature and demold to make the precision TPI - copper - based metal composite binder abrasive tool.

[0027] The beneficial effects of the present invention are:

[0028] The present invention provides a precision TPI - copper - based metal composite binder grinding tool and a preparation method thereof. In the formula of the present invention, a self - made thermoplastic polyimide TPI is added. A large number of ether bonds, alkyl groups and rigid benzene rings are introduced into the molecular structure of TPI, which improves the processability of TPI while making up for the deficiency of heat resistance. Thus, a TPI resin binder with better temperature matching with the copper - based metal binder is obtained. In the composite superhard grinding tool prepared with the copper - based metal binder and the TPI resin binder, the presence of the metal binder plays a role in supporting the framework, ensuring the strength and hardness of the grinding tool; the TPI resin binder increases the elasticity and self - sharpening property of the grinding tool, improves the self - sharpening property during the working process of the grinding tool, and can obtain better workpiece processing surface quality. The resin binder and the copper - based metal binder in the present invention are compounded, which can integrate the advantages of the two and improve the defects of the single resin - based binder superhard grinding tool, such as low strength, fast loss and poor shape retention, as well as the problems of poor self - sharpening property and difficult dressing of the single metal - based binder superhard grinding tool. Detailed Embodiments

[0029] The following embodiments are used to further elaborate the present invention in detail, so that those skilled in the art can implement it according to the description in the specification.

[0030] It should be understood that terms such as "having", "comprising" and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0031] Unless otherwise specified, the test methods used in the following embodiments are all conventional methods. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified. For those not specified in the following embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments not specified in the manufacturer, they are all conventional products that can be purchased commercially.

[0032] A precision TPI - copper - based metal composite binder grinding tool, characterized in that it comprises the following components by weight: 100 parts of abrasive, 10 - 30 parts of resin binder, 60 - 90 parts of copper - based metal binder, and 2 parts of wetting agent;

[0033] Among them, the resin binder is thermoplastic polyimide, and the copper - based metal binder comprises 70wt% - 80wt% of Cu, 12wt% - 20wt% of Sn, and 6wt% - 8wt% of P.

[0034] In a preferred embodiment, the thermoplastic polyimide is prepared by the following method:

[0035] 1) Add 2,2-bis[4-(4-aminophenoxy)phenyl] (BAPP) and 4,4'-oxydianiline (ODA) into a dry four-necked flask equipped with a magnetic stirrer, a condenser, a constant pressure dropping funnel, a thermometer and an N2 interface. Add N,N-dimethylacetamide (DMAC) solution and stir and disperse it in an ice-water bath until completely dissolved;

[0036] 2) Add pyromellitic dianhydride (PMDA) into the DMAC solution, mix evenly, and drop the obtained solution into the product obtained in step 1). Finally, add DMAC solution to adjust the solid content of the obtained mixture to 5-20%. React at 0-5°C for 3-12 h to obtain a polyamic acid (PAA) solution;

[0037] 3) Pour the PAA solution into deionized water for precipitation. After suction filtration, continue to rinse and filter with deionized water, then rinse with ethanol, dry to constant weight under vacuum, grind to obtain a solid powder. Finally, perform thermal imidization on the solid powder under an N2 atmosphere to obtain a thermoplastic polyimide.

[0038] In a preferred embodiment, the thermoplastic polyimide is prepared by the following method:

[0039] 1) Add 2,2-bis[4-(4-aminophenoxy)phenyl] (BAPP) and 4,4'-oxydianiline (ODA) into a dry four-necked flask equipped with a magnetic stirrer, a condenser, a constant pressure dropping funnel, a thermometer and an N2 interface. Add N,N-dimethylacetamide (DMAC) solution and stir and disperse it in an ice-water bath until completely dissolved;

[0040] 2) Add pyromellitic dianhydride (PMDA) into the DMAC solution, mix evenly, and drop the obtained solution into the product obtained in step 1) at a uniform speed within 30 min. Finally, add DMAC solution to adjust the solid content of the obtained mixture to 10%. React at 0-5°C for 6 h to obtain a PAA solution;

[0041] 3) Pour the PAA solution into deionized water for precipitation. After suction filtration, continue to rinse and filter with deionized water, then rinse with ethanol, dry to constant weight under vacuum, grind to obtain a solid powder. Finally, perform thermal imidization on the solid powder under an N2 atmosphere (the thermal imidization process is: rise from room temperature to 300°C in 120 min, keep warm for 1 h, and cool to room temperature) to obtain a thermoplastic polyimide.

[0042] The synthesis route of the thermoplastic polyimide is as follows:

[0043]

[0044] Among them, m and n represent the degree of polymerization (m = 50-100, n = 50-100).

[0045] In a preferred embodiment, the abrasive is a diamond abrasive with a particle size of 400 - 800 mesh.

[0046] In a preferred embodiment, the wetting agent is a polyvinyl alcohol solution. More preferably, the wetting agent is a polyvinyl alcohol solution with a mass concentration of 3 wt%.

[0047] In a preferred embodiment, the wetting agent is prepared by the following method:

[0048] Mix polyvinyl alcohol particles with distilled water, place them in a constant temperature water bath, heat and stir at 98°C for 3 h, and cool to room temperature with cold water to obtain a polyvinyl alcohol solution, which is the wetting agent.

[0049] The present invention also provides a method for preparing the above-mentioned precision TPI - copper - based metal composite binder abrasive tool, including the following steps:

[0050] S1. Mixing: Place the resin binder and the copper - based metal binder in a ball mill and mix them thoroughly and evenly for 15 - 60 min. Pour out and sieve through a 300 - mesh sieve, place them in a three - dimensional mixer together with the abrasive and mix for 10 - 40 min, and finally add the wetting agent and mix for 2 - 10 min to obtain the molding material.

[0051] S2. Pour the molding material into a mold, carry out vacuum hot - press sintering, and demold to make the precision TPI - copper - based metal composite binder abrasive tool.

[0052] In a preferred embodiment, step S1 is specifically: Place the resin binder and the copper - based metal binder in a ball mill and mix them thoroughly and evenly for 30 min, pour out and sieve through a 300 - mesh sieve, place them in a three - dimensional mixer together with the abrasive and mix for 20 min, and finally add the wetting agent and mix for 5 min to obtain the molding material.

[0053] In a preferred embodiment, step S2 is specifically:

[0054] Pour the molding material into a graphite mold, carry out vacuum hot - press sintering, set the pressure to 3.0 MPa, and the sintering curve is: from room temperature, rise to 200°C in 1 min and start vacuum pumping, rise from 200°C to 440°C in 3 min and then hold the pressure and temperature for 6 min, cool from 440°C to 100°C in 5 min, and cool to room temperature and demold to make the precision TPI - copper - based metal composite binder abrasive tool.

[0055] In the present invention, a large number of flexible linkages (ether bonds (-O-)), groups (methyl groups (-CH3)), and rigid benzene rings are introduced into the molecular structure of TPI, enabling TPI to have both good heat resistance and processing performance. As a result, it can be better compounded with a copper-based metal binder to prepare a precision composite binder superhard grinding wheel, which can integrate the advantages of both and improve the defects of single resin binder superhard grinding tools, such as low strength, fast wear, and poor shape retention, as well as the problems of poor self-sharpening and difficult dressing of single metal-based binder superhard grinding tools.

[0056] The above is the overall concept of the present invention. Hereinafter, detailed examples and comparative examples are provided based on this to further illustrate the present invention.

[0057] Example 1:

[0058] A precision TPI-copper-based metal composite binder grinding tool, the preparation method of which includes the following steps:

[0059] 1. Prepare a wetting agent in advance, namely a polyvinyl alcohol solution (PVA solution):

[0060] Before preparation, 3 g of solid PVA particles are mixed with 97 g of distilled water, placed in a constant temperature water bath, heated and stirred at 98 °C for 3 h to prepare a PVA solution with a mass concentration of 3%, and used after cooling.

[0061] 2. Prepare thermoplastic polyimide in advance:

[0062] 1) First, add BAPP and ODA in a certain molar ratio to a dry four-necked flask equipped with magnetic stirring, a condenser, a constant pressure dropping funnel, a thermometer, and an N2 interface, add an appropriate amount of DMAC solution, and stir and disperse in an ice-water bath until completely dissolved.

[0063] 2) Then prepare a DMAC solution of PMDA in a certain molar ratio, use a constant pressure dropping funnel to slowly drop it into the above four-necked flask within 30 min, and finally add a certain amount of DMAC solvent to adjust the solid content to 10%, control the reaction temperature at 0-5 °C, and the reaction time is 6 h to obtain a light yellow viscous PAA solution. Among them, the molar ratio or mass ratio of BAPP:ODA:PMDA is 0.5:0.5:1.02

[0064] 3) Pour the solution into deionized water for precipitation, filter it, continue to wash and filter with deionized water, then wash with ethanol, dry the filtered product under vacuum for a certain time until constant weight, grind it to obtain a solid powder, and finally place the powder in a tubular furnace for thermal imidization under an N2 atmosphere (the thermal imidization process is: from room temperature to 300 °C in 120 min, keep warm for 1 h, and cool to room temperature) to obtain TPI resin powder (thermoplastic polyimide powder).

[0065] 3. Preparation of Precision TPI-Copper-Based Metal Composite Bonded Abrasives:

[0066] S1. Place 10 g of TPI resin powder and 45 g of copper-based metal binder in a ball mill and mix thoroughly for 30 min. Pour out and pass through a 300-mesh sieve. Add the product under the sieve and 55 g of 400# diamond abrasive into a three-dimensional mixer and mix for 20 min. Finally, add 2 g of 3 wt% PVA solution for wetting and mixing for 5 min to obtain the molding material.

[0067] Among them, the copper-based metal binder includes 80 wt% of Cu, 14 wt% of Sn, and 6 wt% of P.

[0068] S2. Pour the molding material into a graphite mold and conduct vacuum hot pressing and sintering. Set the pressure to 3.0 MPa. The sintering curve is as follows: Starting from room temperature, it rises to 200 °C in 1 min and then starts to evacuate. It rises from 200 °C to 440 °C in 3 min, then holds the pressure and temperature for 6 min, and cools from 440 °C to 100 °C in 5 min. After cooling to room temperature, demold to make the precision TPI-copper-based metal composite bonded abrasive.

[0069] Example 2

[0070] A precision TPI-copper-based metal composite bonded abrasive, and its preparation method includes the following steps:

[0071] 1. Prepare a wetting agent in advance, that is, polyvinyl alcohol solution (PVA solution), which is the same as in Example 1;

[0072] Before preparation, mix 3 g of solid PVA particles and 97 g of distilled water, place them in a constant temperature water bath, heat and stir at 98 °C for 3 h to prepare a PVA solution with a mass concentration of 3%. Use it after cooling;

[0073] 2. Prepare thermoplastic polyimide in advance, which is the same as in Example 1;

[0074] 3. Prepare precision TPI-copper-based metal composite bonded abrasives:

[0075] S1. Place 15 g of TPI resin powder and 40 g of copper-based metal binder in a ball mill and mix thoroughly for 30 min. Pour out and pass through a 300-mesh sieve. Add the product under the sieve and 60 g of 600# diamond abrasive into a three-dimensional mixer and mix for 20 min. Finally, add 3 g of 3 wt% PVA solution for wetting and mixing for 5 min to obtain the molding material.

[0076] Among them, the copper-based metal binder includes 80 wt% of Cu, 14 wt% of Sn, and 6 wt% of P.

[0077] S2. Pour the molding material into a graphite mold and perform vacuum hot pressing sintering. The pressure is set to 3.0 MPa. The sintering curve is as follows: vacuum is drawn from room temperature to 200°C after 1 minute, the temperature is raised from 200°C to 440°C after 3 minutes, and then the temperature is kept at a constant temperature and pressure for 6 minutes, the temperature is lowered from 440°C to 100°C after 5 minutes, and the mold is demolded after cooling to room temperature to form a precision TPI-copper-based metal composite binder abrasive tool.

[0078] Example 3

[0079] A precision TPI-copper-based metal composite bond grinding tool, the preparation method of which comprises the following steps:

[0080] 1. Prepare a wetting agent, i.e., a polyvinyl alcohol solution (PVA solution), in advance, which is the same as in Example 1;

[0081] Before preparation, 3 g of solid PVA particles were mixed with 97 g of distilled water, placed in a constant temperature water bath, heated and stirred at 98°C for 3 h to prepare a PVA solution with a mass concentration of 3%, and used after cooling;

[0082] 2. Pre-prepare thermoplastic polyimide, the same as in Example 1;

[0083] 3. Preparation of precision TPI-copper-based metal composite bond abrasive tools:

[0084] S1. 15 g of TPI resin powder and 50 g of copper-based metal binder were placed in a ball mill and mixed thoroughly for 30 min. The mixture was poured through a 300-mesh sieve, and the sieved product was added to a three-dimensional mixer together with 50 g of 800# diamond abrasive and mixed for 20 min. Finally, 4 g of 3 wt% PVA solution was added for wetting and mixing for 5 min to obtain a molding material.

[0085] The copper-based metal binder includes 80 wt % of Cu, 14 wt % of Sn and 6 wt % of P.

[0086] S2. Pour the molding material into a graphite mold and perform vacuum hot pressing sintering. The pressure is set to 3.0 MPa. The sintering curve is as follows: vacuum is drawn from room temperature to 200°C after 1 minute, the temperature is raised from 200°C to 440°C after 3 minutes, and then the temperature is kept at a constant temperature and pressure for 6 minutes, the temperature is lowered from 440°C to 100°C after 5 minutes, and the mold is demolded after cooling to room temperature to form a precision TPI-copper-based metal composite binder abrasive tool.

[0087] Comparative Example 1

[0088] A precision TPI-copper-based metal composite bond grinding tool, the preparation method of which comprises the following steps:

[0089] 1. Prepare a wetting agent, i.e., a polyvinyl alcohol solution (PVA solution), in advance, which is the same as in Example 1;

[0090] 2. Preparation of precision TPI - copper - based metal composite bond grinding tools:

[0091] S1. Put 15 g of TPI resin powder (Tianyi Chemical Co., Ltd., Qinyang City, TY002) and 45 g of copper - based metal bond into a ball mill and mix thoroughly for 30 min. Pour out and sieve through a 300 - mesh sieve. Add the product under the sieve and 55 g of 400# diamond abrasive into a three - dimensional mixer and mix for 20 min. Finally, add 3 g of 3 wt% PVA solution for wetting and mixing for 5 min to obtain the molding material.

[0092] Among them, the copper - based metal bond includes 80 wt% of Cu, 14 wt% of Sn, and 6 wt% of P.

[0093] S2. Pour the molding material into a graphite mold and carry out vacuum hot - press sintering. The pressure is set at 3.0 MPa. The sintering curve is as follows: Starting from room temperature, it rises to 200 °C in 1 min and then starts to evacuate. It rises from 200 °C to 440 °C in 3 min, then holds the temperature and pressure for 6 min, cools from 440 °C to 100 °C in 5 min, and cools to room temperature and demolds to make the precision TPI - copper - based metal composite bond grinding tool.

[0094] Comparative Example 2

[0095] A precision TPI - copper - based metal composite bond grinding tool, and its preparation method includes the following steps:

[0096] 1. Prepare a wetting agent in advance, that is, polyvinyl alcohol solution (PVA solution), which is the same as in Example 1;

[0097] 2. Preparation of precision TPI - copper - based metal composite bond grinding tools:

[0098] S1. Put 20 g of TPI resin powder (Tianyi Chemical Co., Ltd., Qinyang City, TY002) and 55 g of copper - based metal bond into a ball mill and mix thoroughly for 30 min. Pour out and sieve through a 300 - mesh sieve. Add the product under the sieve and 60 g of 600# diamond abrasive into a three - dimensional mixer and mix for 20 min. Finally, add 4 g of 3 wt% PVA solution for wetting and mixing for 5 min to obtain the molding material.

[0099] Among them, the copper - based metal bond includes 80 wt% of Cu, 14 wt% of Sn, and 6 wt% of P.

[0100] S2. Pour the molding material into a graphite mold, and conduct vacuum hot pressing sintering. The pressure is set at 3.0 MPa, and the sintering curve is as follows: Starting from room temperature, it rises to 200 °C in 1 minute and then starts to evacuate. It rises from 200 °C to 440 °C in 3 minutes, then holds the pressure and temperature for 6 minutes, cools from 440 °C to 100 °C in 5 minutes, and is cooled to room temperature and demolded to produce a precision TPI - copper - based metal composite binder grinding tool.

[0101] Perform performance tests on the grinding tools prepared in the examples and comparative examples. The test results are shown in Table 1 below:

[0102] The bending strength test standard is as follows:

[0103] Use a microcomputer - controlled electronic universal testing machine model WDW - 50 to conduct bending strength tests on the metal resin composite binder and grinding tool splines prepared in the experiment in accordance with GB / T 2567 - 2008. The spline size is 5 mm × 5 mm × 50 mm. The electronic universal testing machine uses unconstrained support and conducts three - point bending to break the spline at a constant loading rate. First, adjust the span of the device. The length of the two - point support is 60% of the spline, so the span is adjusted to 30 mm. Immediately, input the corresponding data on the computer control software and adjust the loading rate to 10 mm / min. Stop loading when the maximum loading force appears on the curve. At this time, the spline breaks. Record the load and bending strength when the spline breaks, with the units being kN and MPa respectively.

[0104] The bending strength calculation formula is as follows. Conduct 6 tests and finally take the average value.

[0105]

[0106] Among them, σ t —— Bending strength, unit megapascal (MPa);

[0107] p—— Load at the time of failure load, unit Newton (N);

[0108] l—— Span, unit millimeter (mm);

[0109] b—— Specimen width, unit millimeter (mm);

[0110] h—— Specimen thickness, unit millimeter (mm).

[0111] Table 1

[0112]

[0113]

[0114] As can be seen from the test results in the above table, in a precision TPI-copper-based metal composite bond grinding tool prepared according to an embodiment of the present invention, the TPI resin powder and the copper-based metal bond have better temperature matching, and the strength is superior to that of the composite bond grinding tool prepared with the TPI resin powder purchased on the market. Attributed to the introduction of a large number of ether bonds, alkyl groups and rigid benzene rings in the TPI molecular structure, while improving the processability of TPI, the disadvantage of insufficient heat resistance is compensated, so as to obtain a TPI resin bond with better temperature matching with the copper-based metal bond; the presence of the metal bond in the superhard grinding tool plays a role in supporting the skeleton, ensuring the strength and hardness of the grinding tool; the TPI resin bond increases the elasticity and self-sharpening of the grinding tool, improves the self-sharpening during the working process of the grinding tool, and can obtain better workpiece processing surface quality. It can combine the advantages of the two and improve the defects of low strength, fast loss and poor shape retention of a single resin bond superhard grinding tool, as well as the problems of poor self-sharpening and difficult dressing of a single metal-based bond superhard grinding tool.

[0115] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details.

Claims

1. A precision TPI-copper-based metal composite bond abrasive tool, characterized in that: The invention comprises the following components by weight: 100 parts of abrasive, 10 to 30 parts of resin binder, 60 to 90 parts of copper-based metal binder, and 2 parts of wetting agent; The resin binder is thermoplastic polyimide, and the copper-based metal binder includes 70wt% to 80wt% of Cu, 12wt% to 20wt% of Sn and 6wt% to 8wt% of P.

2. The precision TPI-copper-based metal composite bond grinding tool according to claim 1 is characterized in that: The thermoplastic polyimide is prepared by the following method: 1) Add 2,2-bis[4-(4-aminophenoxy)phenyl] and 4,4'-diaminodiphenyl ether to a dry four-necked flask equipped with a magnetic stirrer, a condenser, a constant pressure dropping funnel, a thermometer and a N2 interface, add N,N-dimethylacetamide solution, and stir and disperse in an ice-water bath until completely dissolved; 2) adding pyromellitic anhydride to N,N-dimethylacetamide solution, mixing evenly, adding the obtained solution dropwise to the product obtained in step 1), and finally adding N,N-dimethylacetamide solution, adjusting the solid content of the obtained mixture to 5-20%, reacting at 0-5° C. for 3-12 hours, and obtaining a polyamic acid solution; 3) The polyamic acid solution is poured into deionized water for precipitation, and after suction filtration, it is continuously rinsed with deionized water, filtered, and then rinsed with ethanol, dried under vacuum to constant weight, and ground to obtain a solid powder, and finally the solid powder is thermally imidized under a N2 atmosphere to obtain a thermoplastic polyimide.

3. The precision TPI-copper-based metal composite bond grinding tool according to claim 2 is characterized in that: The thermoplastic polyimide is prepared by the following method: 1) Add 2,2-bis[4-(4-aminophenoxy)phenyl] and 4,4'-diaminodiphenyl ether to a dry four-necked flask equipped with a magnetic stirrer, a condenser, a constant pressure dropping funnel, a thermometer and a N2 interface, add N,N-dimethylacetamide solution, and stir and disperse in an ice-water bath until completely dissolved; 2) adding pyromellitic anhydride to the N,N-dimethylacetamide solution, mixing evenly, and uniformly adding the obtained solution to the product obtained in step 1) within 30 minutes, and finally adding the N,N-dimethylacetamide solution, adjusting the solid content of the obtained mixture to 10%, reacting at 0-5° C. for 6 hours to obtain a polyamic acid solution; 3) Pour the polyamic acid solution into deionized water for precipitation, continue to rinse with deionized water after suction filtration, filter, and then rinse with ethanol, dry under vacuum to constant weight, grind to obtain solid powder, and finally perform thermal imidization on the solid powder in a N2 atmosphere to obtain thermoplastic polyimide. The thermal imidization process is: from room temperature to 300°C for 120 minutes, keep warm for 1 hour, and cool to room temperature.

4. The precision TPI-copper-based metal composite bond grinding tool according to claim 1, characterized in that: The abrasive is a diamond abrasive with a mesh size of 400 to 800.

5. The precision TPI-copper-based metal composite bond grinding tool according to claim 1, characterized in that: The wetting agent is polyvinyl alcohol solution.

6. The precision TPI-copper-based metal composite bond grinding tool according to claim 5, characterized in that: The wetting agent is a polyvinyl alcohol solution with a mass concentration of 3wt%.

7. The precision TPI-copper-based metal composite bond grinding tool according to claim 6, characterized in that: The wetting agent is prepared by the following method: The polyvinyl alcohol particles were mixed with distilled water, placed in a constant temperature water bath, heated and stirred at 98° C. for 3 hours, and cooled to room temperature to obtain a polyvinyl alcohol solution, namely the wetting agent.

8. A method for preparing a precision TPI-copper-based metal composite bond grinding tool as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Mixing: The resin binder and the copper-based metal binder are placed in a ball mill and mixed evenly for 15-60 minutes, poured out and sieved, placed in a three-dimensional mixer together with the abrasive and mixed for 10-40 minutes, and finally a wetting agent is added and mixed for 2-10 minutes to obtain a molding material; S2, pouring the molding material into the mold, performing vacuum hot pressing sintering, and demolding to produce the precision TPI-copper-based metal composite binder abrasive tool.

9. The method for preparing the precision TPI-copper-based metal composite bond grinding tool according to claim 8, characterized in that: Step S1 is specifically as follows: the resin binder and the copper-based metal binder are placed in a ball mill and mixed evenly for 30 minutes, poured through a 300-mesh sieve, placed together with the abrasive in a three-dimensional mixer and mixed for 20 minutes, and finally a wetting agent is added and mixed for 5 minutes to obtain a molding material.

10. The method for preparing the precision TPI-copper-based metal composite bond grinding tool according to claim 9, characterized in that: Step S2 is specifically as follows: The molding material is poured into a graphite mold and vacuum hot-pressed sintering is performed. The pressure is set to 3.0 MPa. The sintering curve is as follows: vacuum is drawn from room temperature to 200°C after 1 minute, the temperature is raised from 200°C to 440°C after 3 minutes, and then the temperature is kept at a constant temperature and pressure for 6 minutes, the temperature is lowered from 440°C to 100°C after 5 minutes, and the mold is demolded after cooling to room temperature to produce the precision TPI-copper-based metal composite binder abrasive tool.

Images