A method for etching diamond by chemical synergistic physical action

Abstract

The application discloses a method for etching diamond by chemical and physical cooperation, and belongs to the technical field of diamond surface treatment. The method innovatively uses iron-nickel alloy as a grinding ball, and mixes iron powder and nickel powder at a specific ratio as an etchant, so that the physical effect of mechanical ball milling is organically combined with the chemical etching effect of iron and nickel on diamond at high temperature. The steps include diamond pretreatment, mixing, high-energy ball milling etching and post-etching treatment. By adjusting process parameters such as ball milling speed, temperature, time and etchant ratio, precise etching of the diamond surface is realized. The application effectively solves the problems of uneven etching, slow etching rate and complicated process of traditional etching methods, and has the advantages of simple operation, high etching efficiency, uniform etching morphology, low production cost, etc. The application can meet the diversified needs of different fields such as cutting tools and electronic devices for the performance of the diamond surface, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention patent relates to the field of diamond surface treatment technology, and in particular to a method for etching diamond using a chemical-physical synergy. Background Technology

[0002] Diamond possesses a range of excellent properties, including extremely high hardness, superior thermal conductivity, and good chemical stability, making it widely used in cutting tools, abrasives, electronic devices, and optical components. In practical applications, to improve the surface properties of diamond and enhance its bonding with the substrate, surface etching is often required to increase the specific surface area and surface roughness of the diamond.

[0003] Traditional diamond surface etching methods mainly include chemical etching and plasma etching. Chemical etching typically involves a chemical reaction between an etchant and diamond at high temperatures, creating etching pits on the diamond surface. However, this method has a slow etching rate, requires high etching temperatures, and is prone to uneven etching. Plasma etching offers high precision, but the equipment is expensive, the operation is complex, and it is difficult to achieve large-scale industrial production.

[0004] Ball milling, a common powder processing method, combines mechanical impact and mixing, and continuously generates heat during the process. By introducing high-temperature conditions and utilizing the chemical reaction between iron and nickel and diamond at high temperatures, using an iron-nickel alloy as the grinding ball and a mixture of iron and nickel powder as the etchant, combined with the mechanical forces during ball milling, it is hoped that the etching temperature of diamond can be reduced, achieving efficient and uniform etching of the diamond surface. Currently, research and applications of high-energy ball milling for diamond etching are relatively lacking. Therefore, developing a simple, efficient, and uniform chemical-physical synergistic etching method for diamond has significant practical importance and application value. Summary of the Invention

[0005] This innovative method uses an iron-nickel alloy as the grinding ball and a mixture of iron and nickel powder in a specific ratio as the etchant. It organically combines the physical action of mechanical ball milling with the chemical etching effect of iron and nickel metals on the diamond surface under high temperature. Finally, removing metallic impurities yields the etched diamond. Specifically, the mechanical impact and shearing forces generated by the iron-nickel alloy grinding balls during high-energy ball milling create a continuous mechanical impact on the diamond powder, generating defect sites and fresh surface-active areas on the diamond surface. Simultaneously, the high temperature conditions stimulate the chemical reaction between iron, nickel, and diamond, causing the iron and nickel to chemically react with the carbon atoms on the diamond surface, graphitizing the diamond surface. These graphitized diamond particles then detach from the diamond surface under the mechanical force generated by ball milling, achieving highly efficient chemical etching. Furthermore, the high-temperature chemical reaction between diamond and the etchant consumes the etchant. The metal shavings generated by the friction between the iron-nickel alloy grinding balls and the diamond have the same composition as the etchant and do not introduce impurities, thus compensating for the etchant consumption. Finally, removing metallic impurities yields the etched diamond. This method utilizes a synergistic mechanism of mechanical force and high-temperature chemical reaction. It leverages mechanical ball milling to create more reaction sites for chemical etching, while simultaneously using high-temperature chemical etching to precisely etch surface defects formed by mechanical action. These two processes mutually promote and complement each other's shortcomings. This effectively overcomes the common defects in existing diamond etching technologies, such as uneven etching areas, slow etching rates, cumbersome process steps in large-scale industrial production, and difficulty in precisely controlling the etching effect. Ultimately, it provides a simple, efficient, and uniform high-temperature ball milling method for etching diamond, suitable for large-scale production. This meets the diverse surface performance and morphology requirements of diamond in various applications such as cutting tools, electronic devices, and abrasives. Technical solution

[0006] To achieve the objectives of this invention, the following technical solution is adopted: a. Diamond pretreatment: The specific process is as follows: Select diamonds with a particle size of 50-900 μm, clean them in an ultrasonic cleaner with anhydrous ethanol for 20-30 min, then ultrasonically clean them with a 1-3 mol / L HCl solution for 20-30 min, followed by ultrasonic cleaning with a 0.5-1.5 mol / L NaOH solution for 20-30 min, and finally rinse the diamonds with deionized water until the deionized water is neutral. Place the cleaned diamonds in a vacuum drying oven and vacuum dry them at a temperature of 80-120℃ for 3-5 h, then remove them for later use.

[0007] b. Mixing: The specific process is as follows: First, iron powder and nickel powder are mixed evenly at a mass ratio of 1:1-3:1 to serve as the etchant. Then, pretreated diamond is mixed evenly with the etchant at a mass ratio of 1:5-1:7 to serve as the mixture. Finally, iron-nickel alloy grinding balls are mixed evenly with the mixture at a mass ratio of 5:1-10:1 to obtain a ball-material mixture. The mass ratio of iron content to nickel content in the iron-nickel alloy grinding balls is 1:1-3:1.

[0008] c. High-energy ball milling etching: The specific process is as follows: The ball-material mixture obtained in step b is loaded into the grinding jar of a high-energy ball mill, with the loading volume being 30%-45% of the jar volume. After sealing the grinding jar, nitrogen gas is introduced for 10-20 minutes to remove air from the jar. The grinding jar is heated to 500-900℃ at a rate of 10-20℃ / min using a temperature control system. After the temperature stabilizes, the high-energy ball mill is started. First, the rotation speed of the high-energy ball mill is set to 300-600 r / min, and the total running time is 1-3 hours. This process forms a large number of defect sites on the diamond surface. Then, the rotation speed of the high-energy ball mill is set to 100-300 r / min, and the mill is run for 5-7 hours. Finally, heating and ball milling are stopped, and the grinding jar is allowed to cool naturally to room temperature before the ball-milled sample is removed.

[0009] d. Post-etching treatment: The specific process is as follows: First, standard sieves are used to separate powders of different sizes from grinding balls, achieving complete separation of diamond powder and grinding balls. Then, the powder obtained after sieving is immersed in a sufficient amount of 3-5 mol / L HCl solution and magnetically stirred for 30-50 min under water bath heating at 80 ℃, followed by ultrasonic cleaning for 20-30 min to remove residual metallic impurities on the diamond surface. Subsequently, the diamond is repeatedly rinsed with deionized water until the washing solution is neutral, completing the purification. The cleaned diamond is placed in a vacuum drying oven at 80-120 ℃ for 3-5 h and then removed to obtain the diamond with etched surface.

[0010] In step b of this invention, the preferred process for mixing is as follows: First, iron powder and nickel powder are mixed evenly at a mass ratio of 2:1 to serve as an etchant. Then, pretreated diamond is mixed evenly with the etchant at a mass ratio of 1:6 to serve as a mixture. Finally, iron-nickel alloy grinding balls are mixed evenly with the mixture at a mass ratio of 7:1 to obtain a ball-material mixture, wherein the mass ratio of iron content to nickel content in the iron-nickel alloy grinding balls is 2:1.

[0011] The preferred process for high-energy ball milling etching in step c of this invention is as follows: The ball-material mixture obtained in step b is loaded into the grinding jar of a high-energy ball mill, with the loading amount being 40% of the jar's volume. After sealing the grinding jar, nitrogen gas is introduced for 15 minutes to remove air from the jar. The grinding jar is heated to 750°C at a rate of 15°C / min using a temperature control system. After the temperature stabilizes, the high-energy ball mill is started. Initially, the rotation speed of the high-energy ball mill is set to 500 r / min, and the total running time is 2 hours. This process forms a large number of defect sites on the diamond surface. Then, the rotation speed of the high-energy ball mill is set to 200 r / min, and it is run for 6 hours. Finally, heating and ball milling are stopped, and the grinding jar is allowed to cool naturally to room temperature before the ball-milled sample is removed.

[0012] The beneficial effects of this invention are: 1. This invention combines the mechanical force of ball milling with the chemical etching of diamond by iron and nickel at high temperatures. The synergistic effect of these two methods significantly improves the etching efficiency and uniformity of diamond. The mechanical force generated during ball milling creates defect sites on the diamond surface, providing more reaction sites for the chemical etching of diamond by iron and nickel.

[0013] 2. The method of the present invention is simple to operate. By adjusting process parameters such as ball milling speed, temperature, time and the ratio of etchant, it is possible to achieve precise control over the surface morphology and etching degree of diamond, so as to meet the performance requirements of diamond in different application scenarios.

[0014] 3. This invention requires no complex equipment or processes, and the selected grinding media and etchants are low-cost and readily available. Furthermore, the metal shavings consumed by the iron-nickel alloy grinding balls during the ball milling process have the same composition as the etchant, eliminating the need for impurity removal and replenishing the etchant consumed during the etching reaction, further reducing production costs and making it suitable for large-scale industrial production. Detailed Implementation

[0015] The invention will be further described below with reference to specific embodiments: Example

[0016] a. Diamond pretreatment: The specific process is as follows: Select diamonds with a particle size of 200 μm, clean them with anhydrous ethanol in an ultrasonic cleaner for 20 min, then ultrasonically clean them with a 1 mol / L HCl solution for 30 min, followed by ultrasonic cleaning with a 0.5 mol / L NaOH solution for 30 min, and finally rinse the diamonds with deionized water until the deionized water is neutral. Place the cleaned diamonds in a vacuum drying oven and vacuum dry them at 80 ℃ for 5 h, then remove them for later use.

[0017] b. Mixing: The specific process is as follows: First, iron powder and nickel powder are mixed evenly at a mass ratio of 1:1 to serve as the etchant. Then, pretreated diamond is mixed evenly with the etchant at a mass ratio of 1:5 to serve as the mixture. Finally, iron-nickel alloy grinding balls are mixed evenly with the mixture at a mass ratio of 10:1 to obtain a ball-material mixture, wherein the mass ratio of iron content to nickel content in the iron-nickel alloy grinding balls is 1:1.

[0018] c. High-energy ball milling etching: The specific process is as follows: The ball-material mixture obtained in step b is loaded into the grinding jar of a high-energy ball mill, with the loading volume being 30% of the jar's volume. After sealing the grinding jar, nitrogen gas is introduced for 20 minutes to remove air from the jar. The grinding jar is heated to 600 °C at a rate of 10 °C / min using a temperature control system. After the temperature stabilizes, the high-energy ball mill is started. Initially, the rotation speed of the high-energy ball mill is set to 300 r / min, and the total running time is 3 hours. This process forms a large number of defect sites on the diamond surface. Then, the rotation speed of the high-energy ball mill is set to 100 r / min, and it is run for 7 hours. Finally, heating and ball milling are stopped, and the grinding jar is allowed to cool naturally to room temperature before the ball-milled sample is removed.

[0019] d. Post-etching treatment: The specific process is as follows: First, standard sieves are used to separate powders of different sizes from grinding balls, achieving complete separation of diamond powder and grinding balls. Then, the powder obtained after sieving is immersed in a sufficient amount of 3 mol / L HCl solution and magnetically stirred for 50 min under 80 ℃ water bath heating conditions, followed by ultrasonic cleaning for 20 min to remove residual metallic impurities on the diamond surface. Subsequently, the diamond is repeatedly rinsed with deionized water until the washing solution is neutral, completing the purification. The cleaned diamond is placed in a vacuum drying oven at 80 ℃ for 5 h and then removed to obtain the diamond with etched surface.

[0020] Example 2: a. Diamond pretreatment: The specific process is as follows: Select diamonds with a particle size of 400 μm, clean them with anhydrous ethanol for 25 min in an ultrasonic cleaner, then clean them with a 2 mol / L HCl solution for 25 min, followed by ultrasonic cleaning with a 1 mol / L NaOH solution for 25 min, and finally rinse the diamonds with deionized water until the deionized water is neutral. Place the cleaned diamonds in a vacuum drying oven and vacuum dry them at 100 ℃ for 4 h, then remove them for later use.

[0021] b. Mixing: The specific process is as follows: First, iron powder and nickel powder are mixed evenly at a mass ratio of 2:1 to serve as the etchant. Then, pretreated diamond is mixed evenly with the etchant at a mass ratio of 1:6 to serve as the mixture. Finally, iron-nickel alloy grinding balls are mixed evenly with the mixture at a mass ratio of 7:1 to obtain a ball-material mixture. The mass ratio of iron content to nickel content in the iron-nickel alloy grinding balls is 2:1.

[0022] c. High-energy ball milling etching: The specific process is as follows: The ball-material mixture obtained in step b is loaded into the grinding jar of a high-energy ball mill, with the loading volume being 40% of the jar's volume. After sealing the grinding jar, nitrogen gas is introduced for 15 minutes to remove air from the jar. The grinding jar is heated to 750 °C at a rate of 15 °C / min using a temperature control system. After the temperature stabilizes, the high-energy ball mill is started. Initially, the rotation speed of the high-energy ball mill is set to 450 r / min, and the total running time is 2 hours. This process forms a large number of defect sites on the diamond surface. Then, the rotation speed of the high-energy ball mill is set to 200 r / min, and it is run for 6 hours. Finally, heating and ball milling are stopped, and the grinding jar is allowed to cool naturally to room temperature before the ball-milled sample is removed.

[0023] d. Post-etching treatment: The specific process is as follows: First, standard sieves are used to separate powders of different sizes from grinding balls, achieving complete separation of diamond powder and grinding balls. Then, the powder obtained after sieving is immersed in a sufficient amount of 4 mol / L HCl solution and magnetically stirred for 40 min under water bath heating at 80 ℃, followed by ultrasonic cleaning for 25 min to remove residual metallic impurities on the diamond surface. Subsequently, the diamond is repeatedly rinsed with deionized water until the washing solution is neutral, completing the purification. The cleaned diamond is placed in a vacuum drying oven at 100 ℃ for 4 h and then removed to obtain the diamond with etched surface.

[0024] Example 3: a. Diamond pretreatment: The specific process is as follows: Select diamonds with a particle size of 900 μm, clean them with anhydrous ethanol in an ultrasonic cleaner for 30 min, then ultrasonically clean them with a 3 mol / L HCl solution for 20 min, followed by ultrasonic cleaning with a 1.5 mol / L NaOH solution for 20 min, and finally rinse the diamonds with deionized water until the deionized water is neutral. Place the cleaned diamonds in a vacuum drying oven and vacuum dry them at 120 ℃ for 3 h, then remove them for later use.

[0025] b. Mixing: The specific process is as follows: First, iron powder and nickel powder are mixed evenly at a mass ratio of 3:1 to serve as the etchant. Then, pretreated diamond is mixed evenly with the etchant at a mass ratio of 1:7 to serve as the mixture. Finally, iron-nickel alloy grinding balls are mixed evenly with the mixture at a mass ratio of 5:1 to obtain a ball-material mixture. The mass ratio of iron content to nickel content in the iron-nickel alloy grinding balls is 3:1.

[0026] c. High-energy ball milling etching: The specific process is as follows: The ball-material mixture obtained in step b is loaded into the grinding jar of a high-energy ball mill, with the loading volume being 45% of the jar's volume. After sealing the grinding jar, nitrogen gas is introduced for 10 minutes to remove air from the jar. The grinding jar is heated to 900 °C at a rate of 20 °C / min using a temperature control system. After the temperature stabilizes, the high-energy ball mill is started. Initially, the rotation speed of the high-energy ball mill is set to 600 r / min, and the total running time is 1 hour. This process forms a large number of defect sites on the diamond surface. Then, the rotation speed of the high-energy ball mill is set to 300 r / min, and it is run for 5 hours. Finally, heating and ball milling are stopped, and the grinding jar is allowed to cool naturally to room temperature before the ball-milled sample is removed.

[0027] d. Post-etching treatment: The specific process is as follows: First, standard sieves are used to separate powders of different particle sizes from grinding balls, achieving complete separation of diamond powder and grinding balls. Then, the powder obtained after sieving is immersed in a sufficient amount of 5 mol / L HCl solution and magnetically stirred for 30 min under water bath heating at 80 ℃, followed by ultrasonic cleaning for 30 min to remove residual metallic impurities on the diamond surface. Subsequently, the diamond is repeatedly rinsed with deionized water until the washing solution is neutral, completing the purification. The cleaned diamond is placed in a vacuum drying oven at 120 ℃ for 3 h and then removed to obtain the diamond with etched surface.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for etching diamond using a chemical-assisted physical process, characterized in that, Includes the following steps: a. Diamond pretreatment, the specific process is as follows: Select diamonds with a particle size of 50-900 μm, clean them with anhydrous ethanol in an ultrasonic cleaner for 20-30 min, then clean them with HCl solution with a concentration of 1-3 mol / L for 20-30 min, then clean them with NaOH solution with a concentration of 0.5-1.5 mol / L for 20-30 min, and finally rinse the diamonds with deionized water until the deionized water is neutral. Place the cleaned diamonds in a vacuum drying oven and vacuum dry them at a temperature of 80-120 ℃ for 3-5 h, and then take them out for use. b. Mixing, the specific process is as follows: first, iron powder and nickel powder are mixed as an etchant, then the pretreated diamond is mixed with the etchant as a mixture, and finally the iron-nickel alloy grinding ball is mixed with the mixture to obtain a ball-material mixture. The mass ratio of iron content to nickel content in the iron-nickel alloy grinding ball is the same as the ratio of iron powder to nickel powder in the etchant. c. High-energy ball milling etching, the specific process is as follows: The ball material mixture obtained in step b is loaded into the ball milling jar of the high-energy ball mill. After sealing the ball milling jar, nitrogen gas is introduced to remove the air inside the jar. Then the grinding jar is heated to 500-900 ℃, the high-energy ball mill is started, the high-energy ball mill is first set to run at high speed for a period of time, and then the speed is reduced. After stopping heating and ball milling, the grinding jar is allowed to cool naturally to room temperature, and the ball-milled sample is taken out. d. Post-etching treatment: First, standard sieves are used to separate powders of different sizes from grinding balls, achieving complete separation of diamond powder from grinding balls. Then, the powder obtained after sieving is immersed in a sufficient amount of HCl solution, magnetically stirred under water bath heating, and then ultrasonically cleaned. Subsequently, the diamond is repeatedly rinsed with deionized water until the washing solution is neutral. The cleaned diamond is then placed in a vacuum drying oven for drying treatment to obtain diamond with etched surface.

2. The method for etching diamond using chemical synergistic physical action according to claim 1, characterized in that, In step b, iron powder and nickel powder are first mixed evenly at a mass ratio of 1:1 to 3:1 as an etchant. Then, pretreated diamond is mixed evenly with the etchant at a mass ratio of 1:5 to 1:7 as a mixture. Finally, iron-nickel alloy grinding balls are mixed evenly with the mixture at a mass ratio of 5:1 to 10:1 to obtain a ball-material mixture. The mass ratio of iron content to nickel content in the iron-nickel alloy grinding balls is 1:1 to 3:

1.

3. The method for etching diamond using chemical synergistic physical action according to claim 1, characterized in that, In step c, the ball-material mixture is loaded to 30%-45% of the ball mill jar volume, and nitrogen is introduced for 10-20 minutes. The grinding jar is heated to 500-900 ℃ at a rate of 10-20 ℃ / min using a temperature control system. After the temperature stabilizes, the high-energy ball mill is started. First, the rotation speed of the high-energy ball mill is set to 300-600 r / min, and the total running time is 1-3 hours. This process forms a large number of defect sites on the diamond surface. Then, the rotation speed of the high-energy ball mill is set to 100-300 r / min, and it is run for 5-7 hours. Finally, heating and ball milling are stopped, and the grinding jar is allowed to cool naturally to room temperature before the ball-milled sample is taken out.

4. The method for etching diamond using chemical synergistic physical action according to claim 1, characterized in that, In step d, firstly, standard sieves are used to separate powders of different particle sizes from grinding balls, achieving complete separation of diamond powder and grinding balls. Then, the powder obtained after sieving is immersed in a sufficient amount of 3-5 mol / L HCl solution and magnetically stirred for 30-50 min under water bath heating at 80 ℃. Then, ultrasonic cleaning is performed for 20-30 min to remove residual metal impurities on the diamond surface. Subsequently, the diamond is repeatedly rinsed with deionized water until the washing solution is neutral to complete the purification. The cleaned diamond is then placed in a vacuum drying oven at 80-120 ℃ for 3-5 h and then removed to obtain diamond with surface etching.