A water-based polishing liquid for silicon carbide ceramic balls and a method for preparing the polishing liquid

Abstract

The application discloses a water-based grinding fluid for silicon carbide ceramic balls, which comprises silicon carbide powder, boron carbide powder, titanium oxide powder, a suspending agent, a dispersing agent and deionized water, wherein the particle size of the silicon carbide powder is 325-1000 mesh, and the content of the silicon carbide powder is 8-20 wt% of the total mass of the grinding fluid; the particle size of the boron carbide powder is 1000-2000 mesh, and the content of the boron carbide powder is 8-20 wt% of the total mass of the grinding fluid; the titanium oxide powder is a composite material powder of graphene-doped titanium dioxide, the doping amount of the graphene is 10-25 wt% in mass, and the specific surface area of the titanium oxide powder is 80 m 2 / g, and the content of the titanium oxide powder is 8-11 wt% of the total mass of the grinding fluid; the content of the suspending agent is 3-7 wt% of the total mass of the grinding fluid; the content of the dispersing agent is 1.2-8 wt% of the total mass of the grinding fluid; and the pH value of the grinding fluid is 8-10. The application further discloses a preparation method of the grinding fluid. Compared with the prior art, the application can improve the grinding efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of silicon carbide ceramic ball processing, and particularly relates to a water-based grinding fluid for silicon carbide ceramic balls and a preparation method of the grinding fluid. BACKGROUND

[0002] Silicon carbide ceramic material has low density, high hardness, excellent heat resistance (above 1000 DEG C) and chemical stability, and other comprehensive performances, and can effectively reduce the inertial force and centrifugal force of high-speed rotating spindle-bearing parts, and is the first choice for meeting the design requirements of high-precision, high-reliability and long-life bearing systems. However, the high hardness and high brittleness of silicon carbide ceramic material make the high-precision preparation and processing technology of silicon carbide ceramic balls one of the well-known difficult problems. Diamond has the advantages of high hardness, high strength, good toughness, high stability, excellent chemical stability and good self-sharpening performance, and thus becomes the first choice of abrasive materials for the grinding and polishing process of silicon carbide ceramic balls. However, due to the high price of diamond, it is currently mostly used in superfinishing and polishing processes. For the grinding process before the superfinishing stage, the cost is too high if diamond is used.

[0003] At present, the grinding fluid used for the grinding process before the superfinishing stage is divided into oil-based grinding fluid and water-based grinding fluid. The oil-based grinding fluid has the advantages of good lubrication and rust prevention, so that the ceramic grinding and processing of silicon carbide, boron carbide and the like mostly choose the oil-based grinding fluid. However, the oil-based grinding fluid must be cleaned with a solvent, and the discharge of a large amount of solvent can easily cause environmental pollution and harm human health, and has the disadvantage of high economic cost-effectiveness.

[0004] The water-based grinding fluid has the problems of low grinding efficiency and easy breeding of bacteria, but it has good cooling effect and cleaning effect. SUMMARY

[0005] The first technical problem to be solved by the present application is to provide a water-based grinding fluid for silicon carbide ceramic balls to improve the grinding efficiency in view of the current status of the prior art.

[0006] The second technical problem to be solved by the present application is to provide a preparation method of the above-mentioned water-based grinding fluid.

[0007] The technical solution adopted by the present application to solve the above-mentioned first technical problem is as follows: a water-based grinding fluid for silicon carbide ceramic balls, characterized in that it comprises:

[0008] Silicon carbide powder, the particle size of which is 325-1000 mesh, and the content of which is 8-20wt% of the total mass of the grinding fluid;

[0009] Boron carbide powder, the particle size of which is 1000-2000 mesh, and the content of which is 8-20wt% of the total mass of the grinding fluid;

[0010] Titanium oxide powder, composite material powder of graphene doped titanium oxide, and the doping amount of graphene is 10-25% by mass, and the specific surface area of the titanium oxide powder is 80m 2 / g, content is 8-11wt% of total mass of the grinding fluid;

[0011] Suspending agent, content is 3-7wt% of total mass of the grinding fluid;

[0012] Dispersing agent, content is 1.2-8wt% of total mass of the grinding fluid;

[0013] Deionized water;

[0014] The pH value of the grinding fluid is 8-10.

[0015] Preferably, the suspending agent is montmorillonite powder, and the particle size is 0.5μm.

[0016] Further, the dispersing agent is at least two of sodium acrylate, fatty acid modified polyester macromolecule, acyl sarcosinate salt and polyethylene, wherein the content of sodium acrylate is 1-2wt% of total mass of the grinding fluid, the content of fatty acid modified polyester macromolecule is 0.2-2wt% of total mass of the grinding fluid, the content of acyl sarcosinate salt is 2-4wt% of total mass of the grinding fluid, and the content of polyethylene is 1-4wt% of total mass of the grinding fluid.

[0017] In the above solutions, preferably, a pH buffer is further included, the pH buffer is amine citrate or triethanolamine, and the content of the pH buffer is 1-5wt% of total mass of the grinding fluid. The pH buffer can stabilize the pH value of the grinding fluid, and also avoid the gelation or precipitation of other additives due to the change of pH value, thereby ensuring the performance of the grinding fluid.

[0018] In the above solutions, to improve the rust resistance of the grinding fluid, preferably, a rust inhibitor is further included, the rust inhibitor is at least one of hexamethylenetetramine, sodium molybdate and triethanolamine, wherein the content of hexamethylenetetramine is 1-2wt% of total mass of the grinding fluid, the content of sodium molybdate is 1.0-2wt% of total mass of the grinding fluid, and the content of triethanolamine is 0.5-2wt% of total mass of the grinding fluid.

[0019] The technical scheme adopted by the present application to solve the second technical problem is as follows: a preparation method of the water-based grinding fluid for silicon carbide ceramic balls, as described above, characterized in that the steps are as follows:

[0020] I. The powder, i.e. the above-mentioned silicon carbide powder, boron carbide powder, titanium oxide powder, is sequentially added into the water solution with part of the dispersant, and stirring and ultrasonic treatment are simultaneously performed for 30-40 min to obtain a first mixed solution, wherein the content of the dispersant is 0.5-1 wt% of the total mass of the grinding fluid, the stirring speed is 60-80 rpm, the ultrasonic power is 720 W, and the ultrasonic frequency is 25 KHz;

[0021] II. The above-mentioned suspending agent, pH buffer and the remaining dispersant are added into the above-mentioned first mixed solution to obtain a second mixed solution, the pH value of the second mixed solution is controlled to be 8-10, deionized water is selectively added according to the content of each component, and then the second mixed solution is stirred at a stirring speed of 100-120 rpm for 2-3 h to obtain the finished grinding fluid.

[0022] Preferably, the volume ratio of the water solution with part of the dispersant to all the powders in step I is 1:(1-1.3).

[0023] Preferably, step I is performed in a stirring tank, and the bottom of the stirring tank is provided with an ultrasonic generator. Further, the model of the ultrasonic generator is PRM-1012.

[0024] Finally, the pH value of the second mixed solution in step II is adjusted by adding hydrochloric acid or sodium hydroxide solution. The concentration of the hydrochloric acid solution or the sodium hydroxide solution can be configured as required as long as the pH value of the second mixed solution can be adjusted.

[0025] Compared with the prior art, the advantages of the present application are that: the titanium oxide powder doped with graphene can effectively promote the formation rate of the softening layer on the surface of the silicon carbide particles, so that it is easy to be removed from the surface by grinding; the boron carbide and silicon carbide powders with relatively high hardness play a synergistic function with the titanium oxide powder, and in the same processing time, the same material removal effect as the diamond grinding fluid is achieved, and the surface quality of the processed ceramic ball is good with high flatness; and the preparation method of the present application is simple, the prepared grinding fluid has good dispersion stability, high efficiency, and low production cost, and is particularly suitable for grinding processing before the super-fine grinding process of the silicon carbide ceramic ball, i.e. the silicon carbide ceramic ball can be pre-ground by the grinding fluid of the present application, and then super-fine ground by the diamond grinding fluid, so that the processing cost is reduced, the grinding efficiency is improved, and the quality of the product is ensured. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below with reference to the examples.

[0027] Example 1:

[0028] The application discloses a water-based grinding fluid for silicon carbide ceramic balls, which comprises silicon carbide powder, boron carbide powder, titanium oxide powder, deionized water, a suspending agent, a dispersing agent, an anti-rust agent and a pH buffer, wherein the particle size of the silicon carbide powder is 325 mesh, and the content of the silicon carbide powder is 18 wt% of the total mass of the grinding fluid; the particle size of the boron carbide powder is 1600 mesh, and the content of the boron carbide powder is 20 wt% of the total mass of the grinding fluid; the titanium oxide powder is a composite material powder of graphene-doped titanium dioxide (the doping amount of the graphene is 10 wt%), the specific surface area of the titanium oxide powder is 80 m 2 / g, and the content of the titanium oxide powder is 10 wt% of the total mass of the grinding fluid; the suspending agent is montmorillonite powder with a particle size (D 50 ) of 0.5 μm, and the content of the suspending agent is 5 wt% of the total mass of the grinding fluid; the dispersing agent is a fatty acid modified polyester macromolecule (AFCONA-6506 produced by Haimen Evconna), acyl sarcosinate and polyethylene, the content of the fatty acid modified polyester macromolecule is 0.5 wt% of the total mass of the grinding fluid, the content of the acyl sarcosinate is 3 wt% of the total mass of the grinding fluid, and the content of the polyethylene is 1 wt% of the total mass of the grinding fluid; the anti-rust agent is sodium molybdate and triethanolamine, the content of the sodium molybdate is 1.5 wt% of the total mass of the grinding fluid, and the content of the triethanolamine is 1 wt% of the total mass of the grinding fluid; and the pH buffer is amine citrate, and the content of the amine citrate is 3 wt% of the total mass of the grinding fluid.

[0029] The preparation method of the water-based grinding fluid for silicon carbide ceramic balls comprises the following steps:

[0030] I. The powder, i.e. the silicon carbide powder, the boron carbide powder and the titanium oxide powder, is weighed according to the mass percentage of each component, and is prepared for use; firstly, a water solution to which part of the dispersing agent is added (the content of the dispersing agent is 1 wt% of the total mass of the grinding fluid) is added into a stirring tank, and then the silicon carbide powder, the boron carbide powder and the titanium oxide powder are sequentially added into the stirring tank; an ultrasonic generator is placed at the bottom of the stirring tank, and then the stirring tank and the ultrasonic generator are started to stir and perform ultrasonic treatment, wherein the stirring speed is 60 r / min, the ultrasonic power is 720 W, the ultrasonic frequency is 25 KHz, the treatment is performed for 30 min, and then the stirring tank and the ultrasonic generator are stopped, so as to obtain a first mixed solution; the volume ratio of the water solution to which part of the dispersing agent is added to all the powder is 1:1;

[0031] II. The anti-rust agent, the suspending agent, the pH buffer and the remaining dispersing agent are added into the first mixed solution in the stirring tank to obtain a second mixed solution; a sodium hydroxide solution with a concentration of about 10% is used to adjust the pH value of the second mixed solution to 10, deionized water is added according to the content of each component, and then the second mixed solution is stirred at a stirring speed of 100 r / min for 2 h until the mixture is uniform, so as to obtain the finished grinding fluid.

[0032] The polishing liquid prepared in the embodiment is used for polishing processing before the superfinishing process of the silicon carbide ceramic ball, and the processed ceramic ball has good surface quality, high flatness and high polishing efficiency.

[0033] Embodiment 2

[0034] A water-based polishing liquid for silicon carbide ceramic balls, comprising silicon carbide powder, boron carbide powder, titanium oxide powder, deionized water, suspending agent, dispersant, rust inhibitor, and pH buffer, wherein the particle size of the silicon carbide powder is 325 mesh, and the content is 20wt% of the total mass of the polishing liquid; the particle size of the boron carbide powder is 1000 mesh, and the content is 18wt% of the total mass of the polishing liquid; the titanium oxide powder is a composite material powder of graphene-doped titanium dioxide (the doping amount of graphene is 10wt%), and the specific surface area is 80m 2 / g, and the content is 10wt% of the total mass of the polishing liquid; the suspending agent is montmorillonite powder with a particle size (D 50 ) of 0.5μm, and the content is 4wt% of the total mass of the polishing liquid; the dispersant is a fatty acid modified polyester macromolecule (manufacturer: Haimen Afcorna, model: AFCONA-6506), acyl sarcosinate and polyethylene, wherein the content of the fatty acid modified polyester macromolecule is 0.5wt% of the total mass of the polishing liquid, the content of the acyl sarcosinate is 3.5wt% of the total mass of the polishing liquid, and the content of the polyethylene is 1.5wt% of the total mass of the polishing liquid; the rust inhibitor is sodium molybdate, and the content is 1.5wt% of the total mass of the polishing liquid; and the pH buffer is triethanolamine, and the content is 4wt% of the total mass of the polishing liquid.

[0035] The preparation method of the above-mentioned water-based polishing liquid for silicon carbide ceramic balls comprises the following steps:

[0036] I. The powders, i.e. the silicon carbide powder, the boron carbide powder and the titanium oxide powder, are weighed according to the mass percentage of each component, and are prepared for use. First, a water solution with part of the dispersant (the content of the dispersant is 1wt% of the total mass of the polishing liquid) is added to a stirring tank, and then the silicon carbide powder, the boron carbide powder and the titanium oxide powder are sequentially added to the stirring tank. An ultrasonic generator is placed at the bottom of the stirring tank, and then the stirring tank and the ultrasonic generator are started to stir and perform ultrasonic treatment. The stirring speed is 80r / min, the ultrasonic power is 720W, the ultrasonic frequency is 25KHz, and the treatment time is 30min. After the treatment, the stirring tank and the ultrasonic generator are turned off, and thus a first mixed liquid is obtained. The volume ratio of the above-mentioned water solution with part of the dispersant to all the powders is 1:1.3.

[0037] II. The above rust inhibitor, suspending agent, pH buffer and the remaining dispersant are added to the first mixed solution in the stirring tank to obtain a second mixed solution, the pH value of the second mixed solution is adjusted to 10 by using a 20% sodium hydroxide solution, deionized water is added according to the content of each component, then the second mixed solution is stirred, the stirring speed is 120 r / min, the stirring time is 2 h, until the mixture is uniform, thereby obtaining the finished abrasive.

[0038] The abrasive liquid prepared in the embodiment is used for grinding processing before the superfinishing process of the silicon carbide ceramic ball, and the processed ceramic ball has good surface quality, high flatness and high grinding efficiency.

[0039] Example 3:

[0040] A water-based abrasive liquid for silicon carbide ceramic balls, comprising silicon carbide powder, boron carbide powder, titanium oxide powder, deionized water, suspending agent, dispersant, rust inhibitor, pH buffer, wherein the particle size of the silicon carbide powder is 325 mesh, the content is 15wt% of the total mass of the abrasive liquid; the particle size of the boron carbide powder is 1600 mesh, the content is 20wt% of the total mass of the abrasive liquid; the titanium oxide powder is a composite material powder of graphene doped titanium dioxide (the doping amount of graphene is 10wt%), the specific surface area is 80m 2 / g, the content is 9wt% of the total mass of the abrasive liquid; the suspending agent is montmorillonite powder, the particle size (D 50 ) is 0.5μm, the content is 5wt% of the total mass of the abrasive liquid; the dispersant is sodium acrylate, fatty acid modified polyester macromolecule (manufacturer is Haimen Evconna, model is AFCONA-6506) and acyl sarcosinate, wherein the content of sodium acrylate is 1wt% of the total mass of the abrasive liquid, the content of fatty acid modified polyester macromolecule is 0.5wt% of the total mass of the abrasive liquid, the content of acyl sarcosinate is 3.5wt% of the total mass of the abrasive liquid; the rust inhibitor is hexamethylenetetramine and sodium molybdate, the content of hexamethylenetetramine is 1wt% of the total mass of the abrasive liquid, the content of sodium molybdate is 1.5wt% of the total mass of the abrasive liquid; the pH buffer is triethanolamine, the content is 4wt% of the total mass of the abrasive liquid.

[0041] The preparation method of the above-mentioned water-based abrasive liquid for silicon carbide ceramic balls comprises the following steps:

[0042] I. The powders, i.e. silicon carbide powder, boron carbide powder and titanium oxide powder, are weighed according to the mass percentage of each component, and a water solution with part of the dispersant (the content of the dispersant is 1wt% of the total mass of the grinding fluid) is first added to a stirring tank, and then the silicon carbide powder, boron carbide powder and titanium oxide powder are sequentially added to the stirring tank, an ultrasonic generator is placed at the bottom of the stirring tank, and then the stirring tank and the ultrasonic generator are turned on for stirring and ultrasonic treatment, wherein the stirring speed is 60 revolutions / min, the ultrasonic power is 720W, the ultrasonic frequency is 25KHz, and the treatment is performed for 40min, and then the stirring tank and the ultrasonic generator are turned off, thereby obtaining a first mixed solution; the volume ratio of the water solution with part of the dispersant to all the powders is 1:1.1;

[0043] II. The above-mentioned rust inhibitor, suspending agent, pH buffer and remaining dispersant are added to the first mixed solution in the stirring tank to obtain a second mixed solution, a 10% sodium hydroxide solution is used to adjust the pH value of the second mixed solution to 10, deionized water is added according to the content of each component, and then the second mixed solution is stirred at a speed of 110 revolutions / min for 2.5h until it is uniformly mixed, thereby obtaining the finished grinding fluid.

[0044] The grinding fluid prepared in this embodiment is used for grinding processing before the superfinishing process of silicon carbide ceramic balls, and the processed ceramic ball surface has good quality, high flatness and high grinding efficiency.

[0045] Example 4:

[0046] A water-based grinding fluid for silicon carbide ceramic balls, comprising silicon carbide powder, boron carbide powder, titanium oxide powder, deionized water, suspending agent, dispersant, rust inhibitor, pH buffer, wherein the particle size of the silicon carbide powder is 1000 mesh, and the content is 8wt% of the total mass of the grinding fluid; the particle size of the boron carbide powder is 2000 mesh, and the content is 8wt% of the total mass of the grinding fluid; the titanium oxide powder is a composite material powder of graphene-doped titanium dioxide (the doping amount of graphene is 20wt%), and the specific surface area is 80m 2 / g, and the content is 8wt% of the total mass of the grinding fluid; the suspending agent is montmorillonite powder, and the particle size (D 50) is 0.5 μm, and the content is 7 wt% of the total mass of the polishing liquid; the dispersant is sodium acrylate, fatty acid modified polyester macromolecule (manufacturer is Haimen Evcon, model is AFCONA-6506), acyl sarcosinate and polyethylene, wherein the content of sodium acrylate is 2 wt% of the total mass of the polishing liquid, the content of fatty acid modified polyester macromolecule is 0.2 wt% of the total mass of the polishing liquid, the content of acyl sarcosinate is 2 wt% of the total mass of the polishing liquid, and the content of polyethylene is 4 wt% of the total mass of the polishing liquid; the rust inhibitor is hexamethylenetetramine and triethanolamine, the content of hexamethylenetetramine is 2 wt% of the total mass of the polishing liquid, and the content of triethanolamine is 2 wt% of the total mass of the polishing liquid; the pH buffer is amine citrate, and the content is 1 wt% of the total mass of the polishing liquid.

[0047] The preparation method of the above-mentioned water-based polishing liquid for silicon carbide ceramic balls includes the following steps:

[0048] I. The powders, i.e. silicon carbide powder, boron carbide powder and titanium oxide powder, are weighed according to the mass percentage of each component. First, a water solution with part of the dispersant (the content of the dispersant is 0.5 wt% of the total mass of the polishing liquid) is added to a stirring tank, and then the silicon carbide powder, boron carbide powder and titanium oxide powder are sequentially added to the stirring tank. An ultrasonic generator is placed at the bottom of the stirring tank, and then the stirring tank and the ultrasonic generator are started to stir and perform ultrasonic treatment at the same time. The stirring speed is 70 revolutions / min, the ultrasonic power is 720 W, the ultrasonic frequency is 25 KHz, and the treatment time is 35 min. After the treatment, the stirring tank and the ultrasonic generator are turned off, and a first mixed liquid is obtained. The volume ratio of the water solution with part of the dispersant to all the powders is 1:1.

[0049] II. The rust inhibitor, suspending agent, pH buffer and remaining dispersant are added to the first mixed liquid in the stirring tank to obtain a second mixed liquid. A sodium hydroxide solution with a concentration of about 10% is used to adjust the pH value of the second mixed liquid to 9. Deionized water is added according to the content of each component, and then the second mixed liquid is stirred at a speed of 100 revolutions / min for 3 h until it is uniformly mixed, thereby obtaining a finished polishing liquid.

[0050] The polishing liquid prepared in this embodiment is used for grinding processing before the superfinishing process of silicon carbide ceramic balls. The processed ceramic balls have good surface quality, high flatness and high grinding efficiency.

Claims

1. A water-based polishing liquid for silicon carbide ceramic balls, characterized by The application relates to a grinding fluid, which comprises the following components: Silicon carbide powder with a particle size of 325-1000 mesh, and the content is 8-20wt% of the total mass of the grinding fluid; Boron carbide powder with a particle size of 1000-2000 mesh, and the content is 8-20wt% of the total mass of the grinding fluid; Titanium oxide powder, a composite material powder of graphene-doped titanium dioxide, and the doping amount of graphene is 10-25% by mass, and the specific surface area of the titanium oxide powder is 80 m 2 / g, and the content is 8-11 wt% of the total mass of the polishing liquid; Suspending agent, and the content is 3-7wt% of the total mass of the grinding fluid; Dispersing agent, and the content is 1.2-8wt% of the total mass of the grinding fluid; Deionized water; The pH value of the grinding fluid is 8-10.

2. The water-based polishing liquid for silicon carbide ceramic balls according to claim 1, characterized by: The suspending agent is montmorillonite powder with a particle size of 0.5 microns.

3. The water-based polishing liquid for silicon carbide ceramic balls according to claim 2, characterized by: The dispersing agent is at least two of sodium acrylate, fatty acid modified polyester macromolecule, acyl sarcosinate and polyethylene, wherein the content of sodium acrylate is 1-2wt% of the total mass of the grinding fluid, the content of the fatty acid modified polyester macromolecule is 0.2-2wt% of the total mass of the grinding fluid, the content of acyl sarcosinate is 2-4wt% of the total mass of the grinding fluid, and the content of polyethylene is 1-4wt% of the total mass of the grinding fluid.

4. The water-based slurry for silicon carbide ceramic balls according to any one of claims 1 to 3, characterized by: The pH buffer is amine citrate or triethanolamine, and the content of the pH buffer is 1-5wt% of the total mass of the grinding fluid.

5. The water-based slurry for silicon carbide ceramic balls according to any one of claims 1 to 3, characterized by: The rust inhibitor is at least one of hexamethylenetetramine, sodium molybdate and triethanolamine, wherein the content of hexamethylenetetramine is 1-2wt% of the total mass of the grinding fluid, the content of sodium molybdate is 1.0-2wt% of the total mass of the grinding fluid, and the content of triethanolamine is 0.5-2wt% of the total mass of the grinding fluid.

6. A method of producing a water-based polishing liquid for silicon carbide ceramic balls according to claim 4, characterized by The steps are as follows: I. The powders, i.e. the above-mentioned silicon carbide powder, boron carbide powder and titanium oxide powder, are sequentially added into a water solution with part of the dispersing agent, and stirring and ultrasonic treatment are simultaneously conducted for 30-40 minutes to obtain a first mixed solution, wherein the content of the dispersing agent is 0.5-1wt% of the total mass of the grinding fluid, the stirring speed is 60-80 revolutions per minute, the ultrasonic power is 720W, and the ultrasonic frequency is 25KHz; II. The suspending agent, the pH buffer and the remaining dispersing agent are added into the first mixed solution to obtain a second mixed solution, the pH value of the second mixed solution is controlled to be 8-10, deionized water is selectively added according to the content of each component, and then the second mixed solution is stirred at a speed of 100-120 revolutions per minute for 2-3 hours, so that the finished grinding fluid is obtained.

7. The method of claim 6, wherein: The volume ratio of the water solution with part of the dispersing agent to all the powders in the step I is 1:(1-1.3).

8. The method of claim 6, wherein: The step I is conducted in a stirring tank, and an ultrasonic generator is arranged at the bottom of the stirring tank.

9. The method of claim 6, wherein: In the step II, hydrochloric acid or sodium hydroxide solution is added to adjust the pH value of the second mixed solution.