Composite diamond micro-powder for diamond wire saw and preparation process thereof

Abstract

This invention relates to the field of diamond tool technology, specifically to a composite diamond micropowder for diamond wire saws and its preparation process. To improve the high-temperature resistance of resin-bonded diamond wire saws, this invention prepares a composite diamond micropowder for diamond wire saws. By introducing benzene rings onto the surface of the diamond micropowder, the high-temperature resistance of the diamond micropowder after curing with the epoxy resin binder is improved. Furthermore, ether bonds are introduced onto the surface to enhance molecular flexibility, thereby improving impact resistance and effectively preventing diamond abrasive shedding due to friction and impact, as well as the decline in wire saw performance caused by frictional heat, thus improving the working efficiency of the wire saw. Furthermore, this invention further introduces epoxy groups onto the surface of the diamond abrasive, thereby increasing the bonding strength between the diamond abrasive and the epoxy resin, effectively preventing abrasive shedding during the use of the diamond wire saw.

Description

Technical Field

[0001] This invention relates to the field of diamond tool technology, specifically to a composite diamond micro powder for diamond wire saws and its preparation process. Background Technology

[0002] Resin-bonded diamond wire saws are manufactured by fixing diamond micropowder to the surface of a metal wire using a resin binder, followed by curing at high temperatures. Compared to traditional silicon carbide free abrasives, especially in silicon wafer cutting, resin-bonded diamond wire saws often offer more efficient slicing, smaller kerfs, higher yields, and superior slice surface quality. However, compared to electroplated diamond wire saws, resin-bonded diamond wire saws have poorer durability, the diamond abrasive is prone to peeling, and they are not heat-resistant, which often limits their application range. Therefore, it is necessary to address these shortcomings to meet market demands. Summary of the Invention

[0003] The purpose of this invention is to provide a composite diamond micro powder for diamond wire saws and its preparation process, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0005] S1. Disperse diamond micro powder in deionized water, stir and mix for 20-30 min, filter, wash diamond micro powder with ultrapure water 3-5 times, evaporate and dry diamond micro powder under vacuum at 60-80℃ for 12-24 h, then disperse it again in a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid, ultrasonically disperse for 4-8 h, heat the mixed acid solution to 75-85℃, continue the reaction for 24-36 h, centrifuge, filter off the supernatant, add the precipitate to an ice-water mixture, stir and mix for 1-2 h, filter, wash the precipitate with hydrochloric acid solution 3-5 times, wash the precipitate with deionized water until neutral, dry under vacuum at 60℃ for 12-24 h to obtain carboxylated diamond micro powder;

[0006] S2. Mix carboxylated diamond micro powder with DMF and stir for 1-4 hours to obtain a carboxylated diamond micro powder dispersion;

[0007] Hydroquinone dihydroxyethyl ether was dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30-45 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75-80℃ and reacted for 1-1.5 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30-90 min, the precipitate was added dropwise to a xylene solution containing 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, zinc acetate was added and the mixture was stirred for another 5-10 min. The mixture was then heated to 90-100℃ and reacted for 2-8 h. The precipitate was then separated by centrifugation and washed 2-3 times with DMAc. Finally, the precipitate was vacuum dried for 6-12 h to obtain long-chain carboxylated diamond micropowder.

[0008] S3. Disperse long-chain carboxylated diamond micro powder in toluene and ultrasonically disperse for 12 h to obtain a dispersion of long-chain carboxylated diamond micro powder;

[0009] 1,2,4-Tris(epoxyalkylmethyl) 1,2,4-phenyltricarboxylate was dispersed in xylene and stirred for 30-45 min under a nitrogen atmosphere. The mixture was then cooled to 0-5°C, and 4-aminotriphenylamine was added. The mixture was slowly heated to 80-95°C at a rate of 0.5-2°C / min and stirred for 50-100 min. After cooling to room temperature, a dispersion of long-chain carboxylated diamond micropowder was added dropwise. After the addition was complete, the temperature was raised again to 75-85°C and the reaction was continued for 2-4 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micropowder for diamond wire saws.

[0010] Furthermore, in step S1, the diamond powder is composed of 50-65% micron-sized diamond powder and 35-50% submicron-sized diamond powder.

[0011] The micron-sized diamond powder has a particle size of 5-30 micrometers; the submicron-sized diamond powder has a particle size of 1.5-3 micrometers.

[0012] Furthermore, in step S1, the mass ratio of the diamond micro powder to the mixed acid solution is 1:(20-50) by weight.

[0013] Furthermore, in step S2, the mass ratio of hydroquinone dihydroxyethyl ether to carboxylated diamond is (10-20):1, based on parts by weight.

[0014] Furthermore, in step S2, the mass ratio of carboxylated diamond, 4,4'-diphenyl ether dicarboxylic acid, and zinc acetate is 1:(5-15):(0.05-0.08) by weight.

[0015] Furthermore, in step S3, the mass ratio of the long-chain carboxylated diamond micro powder, tris(epoxyethylene methyl) 1,2,4-benzenetricarboxylate, and 4-aminotriphenylamine is 1:15:(8.25-10.35) by weight.

[0016] Furthermore, the composite diamond micro powder is used in the preparation of resin-bonded diamond wire saws, and the resin binder used in the preparation is epoxy resin.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] To improve the high-temperature resistance of resin-bonded diamond wire saws, this invention prepares composite diamond micropowder for diamond wire saws. To enhance the compatibility and bonding strength between the diamond micropowder and the epoxy resin binder, this invention first uses a strong acid solution to acidify and oxidize the diamond micropowder, generating carboxyl groups on its surface, thereby enhancing the reactivity of the diamond micropowder. Then, this invention further reacts the carboxylated diamond micropowder with hydroquinone dihydroxyethyl ether, introducing an aromatic benzene ring structure onto the diamond surface. The introduction of the benzene ring structure effectively improves the high-temperature stability of the epoxy resin, enhancing the long-term working performance of the diamond wire saw, thus avoiding the impact of frictional heat generated during long-term operation on the wire saw's performance. Furthermore, this invention also uses 4,4'... The reaction of diphenyl ether with dicarboxylic acid further increases the carbon chain structure grafted onto the diamond surface, increasing the benzene ring content and introducing ether bonds. The introduction of ether bonds can improve the flexibility of the molecule, thereby reducing the defects caused by excessive rigidity due to the introduction of excessive benzene rings. This reduces the loss of diamond abrasive due to friction and impact during diamond wire saw cutting, improving the working efficiency of the wire saw. Furthermore, this invention further uses 1,2,4-tris(epoxyethylene methyl) 1,2,4-phenyltricarboxylate reacting with 4-aminotriphenylamine, followed by reaction with diamond micropowder, to further introduce epoxy groups onto the surface of the diamond abrasive, thereby improving the bonding strength between the diamond abrasive and epoxy resin and effectively preventing abrasive loss during the use of the diamond wire saw. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The micron-sized diamond abrasive used in this application is diamond micro powder with a particle size of W20, provided by Henan Hengwei Superhard Materials Co., Ltd.; the submicron-sized diamond micro powder used is diamond micro powder with a particle size of W3, provided by Henan Hengwei Superhard Materials Co., Ltd.; the hydroquinone dihydroxyethyl ether used is provided by Shanghai Haohong Biomedical Technology Co., Ltd.; the 4,4'-diphenyl ether dicarboxylic acid used is provided by Hubei Xingyan New Materials Technology Co., Ltd.; the 1,2,4-tris(ethylene oxide methyl) 1,2,4-phenyltricarboxylic acid tris(ethylene oxide methyl) ester used is provided by Shaanxi Didu New Materials Co., Ltd.; and the 4-aminotriphenylamine used is provided by Shanghai Aladdin Biochemical Technology Co., Ltd.

[0021] Example 1. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0022] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in a mixed acid solution of 20 parts of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation, the supernatant is filtered off, and the precipitate is added to a mixture of 100 parts of ice water, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried under vacuum at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0023] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0024] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0025] S2. By weight, 1 part of carboxylated diamond micro powder and 10 parts of DMF are mixed and stirred for 1 hour to obtain a carboxylated diamond micro powder dispersion.

[0026] Ten parts of hydroquinone dihydroxyethyl ether were dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75°C and reacted for 1 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30 min, the precipitate was added dropwise to a xylene solution containing 5 parts of 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, 0.05 parts of zinc acetate were added. The mixture was stirred for another 5 min and then heated to 90°C. After reacting for 2 h, the precipitate was separated by centrifugation. The precipitate was washed twice with DMAc and then vacuum dried for 6 h to obtain long-chain carboxylated diamond micropowder.

[0027] S3. By weight, 1 part of long-chain carboxylated diamond micro powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a dispersion of long-chain carboxylated diamond micro powder.

[0028] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. The mixture was then cooled to 0-5℃, and 8.25 parts of 4-aminotriphenylamine were added. The mixture was slowly heated to 80℃ at a rate of 0.5℃ / min. After stirring for 50 min, the mixture was cooled to room temperature, and a dispersion of long-chain carboxylated diamond micropowder was added dropwise. After the addition was completed, the temperature was raised to 75℃ again, and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micropowder for diamond wire saws.

[0029] Example 2. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0030] Compared with Example 1, this example increases the amount of 4-aminotriphenylamine added in step S3;

[0031] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in a mixed acid solution of 20 parts of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation, the supernatant is filtered off, and the precipitate is added to a mixture of 100 parts of ice water, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried under vacuum at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0032] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0033] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0034] S2. By weight, 1 part of carboxylated diamond micro powder and 10 parts of DMF are mixed and stirred for 1 hour to obtain a carboxylated diamond micro powder dispersion.

[0035] Ten parts of hydroquinone dihydroxyethyl ether were dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75°C and reacted for 1 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30 min, the precipitate was added dropwise to a xylene solution containing 5 parts of 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, 0.05 parts of zinc acetate were added. The mixture was stirred for another 5 min and then heated to 90°C. After reacting for 2 h, the precipitate was separated by centrifugation. The precipitate was washed twice with DMAc and then vacuum dried for 6 h to obtain long-chain carboxylated diamond micropowder.

[0036] S3. By weight, 1 part of long-chain carboxylated diamond micro powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a dispersion of long-chain carboxylated diamond micro powder.

[0037] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. The mixture was then cooled to 0-5℃, and 10.35 parts of 4-aminotriphenylamine were added. The mixture was slowly heated to 80℃ at a rate of 0.5℃ / min. After stirring for 50 min, the mixture was cooled to room temperature. A dispersion of long-chain carboxylated diamond micropowder was then added dropwise. After the addition was complete, the temperature was raised to 75℃ again, and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micropowder for diamond wire saws.

[0038] Example 3. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0039] Compared with Example 1, this example increases the amount of hydroquinone dihydroxyethyl ether added in step S2;

[0040] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in a mixed acid solution of 20 parts of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation, the supernatant is filtered off, and the precipitate is added to a mixture of 100 parts of ice water, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried under vacuum at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0041] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0042] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0043] S2. By weight, 1 part of carboxylated diamond micro powder and 10 parts of DMF are mixed and stirred for 1 hour to obtain a carboxylated diamond micro powder dispersion.

[0044] Twenty parts of hydroquinone dihydroxyethyl ether were dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75°C and reacted for 1 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30 min, the precipitate was added dropwise to a xylene solution containing 5 parts of 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, 0.05 parts of zinc acetate were added. The mixture was stirred for another 5 min and then heated to 90°C. After reacting for 2 h, the precipitate was separated by centrifugation. The precipitate was washed twice with DMAc and then vacuum dried for 6 h to obtain long-chain carboxylated diamond micropowder.

[0045] S3. By weight, 1 part of long-chain carboxylated diamond micro powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a dispersion of long-chain carboxylated diamond micro powder.

[0046] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. The mixture was then cooled to 0-5℃, and 8.25 parts of 4-aminotriphenylamine were added. The mixture was slowly heated to 80℃ at a rate of 0.5℃ / min. After stirring for 50 min, the mixture was cooled to room temperature, and a dispersion of long-chain carboxylated diamond micropowder was added dropwise. After the addition was completed, the temperature was raised to 75℃ again, and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micropowder for diamond wire saws.

[0047] Example 4. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0048] Compared with Example 1, this example increases the amount of 4,4'-diphenyl ether dicarboxylic acid added in step S2;

[0049] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in a mixed acid solution of 20 parts of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation, the supernatant is filtered off, and the precipitate is added to a mixture of 100 parts of ice water, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried under vacuum at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0050] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0051] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0052] S2. By weight, 1 part of carboxylated diamond micro powder and 10 parts of DMF are mixed and stirred for 1 hour to obtain a carboxylated diamond micro powder dispersion.

[0053] Ten parts of hydroquinone dihydroxyethyl ether were dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75°C and reacted for 1 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30 min, the precipitate was added dropwise to a xylene solution containing 15 parts of 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, 0.05 parts of zinc acetate were added. The mixture was stirred for another 5 min and then heated to 90°C. After reacting for 2 h, the precipitate was separated by centrifugation. The precipitate was washed twice with DMAc and then vacuum dried for 6 h to obtain long-chain carboxylated diamond micropowder.

[0054] S3. By weight, 1 part of long-chain carboxylated diamond micro powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a dispersion of long-chain carboxylated diamond micro powder.

[0055] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. The mixture was then cooled to 0-5℃, and 8.25 parts of 4-aminotriphenylamine were added. The mixture was slowly heated to 80℃ at a rate of 0.5℃ / min. After stirring for 50 min, the mixture was cooled to room temperature, and a dispersion of long-chain carboxylated diamond micropowder was added dropwise. After the addition was completed, the temperature was raised to 75℃ again, and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micropowder for diamond wire saws.

[0056] Example 5. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0057] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in 50 parts of a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation and filtration of the supernatant, the precipitate is added to 100 parts of an ice-water mixture, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0058] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0059] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0060] S2. By weight, 1 part of carboxylated diamond micro powder and 10 parts of DMF are mixed and stirred for 1 hour to obtain a carboxylated diamond micro powder dispersion.

[0061] Twenty parts of hydroquinone dihydroxyethyl ether were dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75°C and reacted for 1 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30 min, the precipitate was added dropwise to a xylene solution containing 15 parts of 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, 0.08 parts of zinc acetate were added. The mixture was stirred for another 5 min and then heated to 90°C. After reacting for 2 h, the precipitate was separated by centrifugation. The precipitate was washed twice with DMAc and then vacuum dried for 6 h to obtain long-chain carboxylated diamond micropowder.

[0062] S3. By weight, 1 part of long-chain carboxylated diamond micro powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a dispersion of long-chain carboxylated diamond micro powder.

[0063] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. The mixture was then cooled to 0-5℃, and 10.35 parts of 4-aminotriphenylamine were added. The mixture was slowly heated to 80℃ at a rate of 0.5℃ / min. After stirring for 50 min, the mixture was cooled to room temperature. A dispersion of long-chain carboxylated diamond micropowder was then added dropwise. After the addition was complete, the temperature was raised to 75℃ again, and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micropowder for diamond wire saws.

[0064] Comparative Example 1. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0065] Compared to Example 1, this comparative example did not use 4-aminotriphenylamine to treat the diamond powder;

[0066] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in a mixed acid solution of 20 parts of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation, the supernatant is filtered off, and the precipitate is added to a mixture of 100 parts of ice water, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried under vacuum at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0067] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0068] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0069] S2. By weight, 1 part of carboxylated diamond micro powder and 10 parts of DMF are mixed and stirred for 1 hour to obtain a carboxylated diamond micro powder dispersion.

[0070] Ten parts of hydroquinone dihydroxyethyl ether were dispersed in pure DMF. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, carboxylated diamond dispersion was slowly added dropwise while continuously stirring the mixture during the addition. After the addition was completed, the mixture was heated to 75°C and reacted for 1 h. The precipitate was then separated by centrifugation and dispersed in toluene. After ultrasonic vibration for 30 min, the precipitate was added dropwise to a xylene solution containing 5 parts of 4,4'-diphenyl ether dicarboxylic acid. After the addition was completed, 0.05 parts of zinc acetate were added. The mixture was stirred for another 5 min and then heated to 90°C. After reacting for 2 h, the precipitate was separated by centrifugation. The precipitate was washed twice with DMAc and then vacuum dried for 6 h to obtain long-chain carboxylated diamond micropowder.

[0071] S3. By weight, 1 part of long-chain carboxylated diamond micro powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a dispersion of long-chain carboxylated diamond micro powder.

[0072] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. Then, a long-chain carboxylated diamond micro powder dispersion was added dropwise. After the addition was completed, the temperature was raised to 75℃ again and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micro powder for diamond wire saws.

[0073] Comparative Example 2. A preparation process for composite diamond micro powder for diamond wire saws, comprising the following steps:

[0074] Compared with Example 1, the diamond micro powder in this comparative example was not processed in step S2;

[0075] S1. By weight, 1 part of diamond micro powder is dispersed in 100 parts of deionized water, stirred and mixed for 20 min, filtered, washed with ultrapure water 3 times, and then the diamond micro powder is vacuum dried at 60°C for 12 h. It is then dispersed again in a mixed acid solution of 20 parts of concentrated nitric acid and concentrated sulfuric acid, and ultrasonically dispersed for 4 h. The mixed acid solution is heated to 75°C and the reaction is continued for 24 h. After centrifugation, the supernatant is filtered off, and the precipitate is added to a mixture of 100 parts of ice water, stirred and mixed for 1 h, filtered, and the precipitate is washed with hydrochloric acid solution 3 times. The precipitate is then washed with deionized water until neutral and dried under vacuum at 60°C for 12 h to obtain carboxylated diamond micro powder.

[0076] The diamond powder, by weight percentage, consists of 65% micron-sized diamond powder and 35% submicron-sized diamond powder.

[0077] The mixed acid solution is composed of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1;

[0078] S2. By weight, 1 part of carboxylated diamond powder was dispersed in toluene and ultrasonically dispersed for 12 hours to obtain a carboxylated diamond powder dispersion.

[0079] 15 parts of 1,2,4-benzenetricarboxylic acid tris(epoxyethylene methyl) ester were dispersed in xylene. Under a nitrogen atmosphere, the mixture was stirred for 30 min. The mixture was then cooled to 0-5℃, and 8.25 parts of 4-aminotriphenylamine were added. The mixture was slowly heated to 80℃ at a rate of 0.5℃ / min. After stirring for 50 min, the mixture was cooled to room temperature, and carboxylated diamond micro powder dispersion was added dropwise. After the addition was completed, the temperature was raised to 75℃ again, and the reaction was continued for 2 h. The mixture was then centrifuged and vacuum evaporated to constant weight to obtain composite diamond micro powder for diamond wire saws.

[0080] To prepare a diamond wire saw, 60 parts by weight of bisphenol A type E51 epoxy resin, 20 parts of phenolic resin 2127, and 8 parts of nano-alumina were mixed. After vacuum degassing, composite diamond micro powder for diamond wire saws was added at a ratio of 30 ct / ml. After thorough stirring, the mixture was coated onto a copper-plated high-carbon steel wire substrate with a diameter of 120 micrometers and a copper plating thickness of 0.15 micrometers. After coating, the substrate was dried and cured at 300℃ for 2 hours to obtain the diamond wire saw.

[0081] Using an STX-402 cutting machine with a loaded diamond wire saw, and a 3-inch single-crystal silicon rod as the cutting medium, the effective cutting length of the diamond wire saw was 2.5m, and the cutting speed was 2.5m / s. The cutting speed of the silicon rod and the diamond detachment rate when the wire broke were tested. The test results are shown in the table below.

[0082] Cutting speed (mm / h) Diamond detachment rate upon wire breakage (%) Example 1 38 8.7 Example 2 41 7.9 Example 3 39 8.2 Example 4 39 8.1 Example 5 43 7.7 Comparative Example 1 36 8.9 Comparative Example 2 34 9.6

[0083] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for preparing a composite diamond micro powder for a diamond wire saw, characterized by, Comprising the following steps: S1. Disperse the diamond powder into deionized water, after stirring and mixing for 20-30 min, filter, wash the diamond powder with ultrapure water for 3-5 times, then vacuum evaporate and dry the diamond powder at 60-80℃ for 12-24h, then disperse it into a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid, ultrasonic shock and dispersion reaction for 4-8h, then heat the mixed acid solution to 75-85℃, continue to react for 24-36h, centrifugal separation, filter the supernatant, then add the precipitate into an ice water mixture, stir and mix for 1-2h, filter, wash the precipitate with hydrochloric acid solution for 3-5 times, then wash the precipitate to neutral with deionized water, vacuum dry at 60℃ for 12-24h, then obtain the carboxylated diamond powder; In step S1, the diamond powder is composed of 50-65% micron diamond powder and 35-50% sub-micron diamond powder; The micron diamond powder has a particle size of 5-30 microns; the sub-micron diamond powder has a particle size of 1.5-3 microns; S2. Mix the carboxylated diamond powder with DMF, stir and mix for 1-4h, then obtain the carboxylated diamond powder dispersion liquid; Disperse the hydroquinone dihydroxyethyl ether into pure DMF, under nitrogen atmosphere, stir and mix for 30-45min, then slowly add the carboxylated diamond dispersion liquid, constantly stir the mixed solution during the adding process, after the adding process, heat the mixed solution to 75-80℃, react for 1-1.5h, then centrifugal separation, disperse the precipitate into toluene, ultrasonic shock for 30-90min, then add it into the xylene solution dispersed with 4,4'-diphenyl ether dicarboxylic acid, after the adding process, add zinc acetate, continue to stir for 5-10min, then heat to 90-100℃, react for 2-8h, then centrifugal separation, wash the precipitate with DMAc for 2-3 times, then vacuum dry the precipitate for 6-12h, then obtain the long carbon chain carboxylated diamond powder; In step S2, the mass ratio of the hydroquinone dihydroxyethyl ether and the carboxylated diamond is (10-20):1; the mass ratio of the carboxylated diamond, 4,4'-diphenyl ether dicarboxylic acid and zinc acetate is 1:(5-15):(0.05-0.08); S3. Disperse the long carbon chain carboxylated diamond powder into toluene, ultrasonic dispersion for 12h, then obtain the long carbon chain carboxylated diamond powder dispersion liquid; Disperse 1,2,4-benzene tricarboxylic acid tris(oxiranylmethyl) ester into xylene, under nitrogen atmosphere, stir and mix for 30-45min, then cool the mixed solution to 0-5℃, add 4-amino triphenylamine, slowly heat the mixed solution to 80-95℃ at a rate of 0.5-2℃ / min, stir and react for 50-100min, then cool to room temperature, then add the long carbon chain carboxylated diamond powder dispersion liquid, after the adding process, heat to 75-85℃ again, continue to react for 2-4h, centrifugal separation, vacuum evaporation to constant weight, then obtain the composite diamond powder for diamond wire saw; In step S3, the mass ratio of the long carbon chain carboxylated diamond micro-powder, 1,2,4-benzene tricarboxylic acid tris(oxymethylene methyl) ester and 4-amino triphenylamine is 1:15:(8.25-10.35) by weight.

2. The preparation process of the composite diamond micro-powder for the diamond wire saw according to claim 1, characterized in that: In step S1, the mass ratio of the diamond micro-powder and the mixed acid solution is 1:(20-50) by weight. In the mixed acid solution, the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:(3-3.5).

3. The composite diamond micro-powder prepared by the preparation process according to any one of claims 1-2.

4. The composite diamond micro powder for a diamond wire saw according to claim 3, characterized by: The composite diamond micro-powder is used for preparing a resin bond diamond wire saw, and the resin binder is an epoxy resin during the preparation.