Composite abrasive particle, preparation method thereof and polishing solution

Abstract

The invention discloses a composite abrasive particle, a preparation method of the composite abrasive particle and a polishing solution. The preparation method of the composite abrasive particle comprises the following steps that sodium silicate nonahydrate serves as a raw material, and porous SiO2 is prepared through a template method; porous SiO2 and aluminum nitrate nonahydrate are used as raw materials, a chemical precipitation method is utilized, the surface of the porous SiO2 is coated with a layer of fibrous gamma-Al2O3 by regulating and controlling the reaction rate, so that the composite abrasive particles are obtained, the composite abrasive particles are of a core-shell structure, the porous SiO2 is used as an inner core, the fibrous gamma-Al2O3 is used as an outer shell, and the polishing solution contains 3-10 wt% of the composite abrasive particles. The composite abrasive particle has good dispersity, high deformability, a high-hardness shell, a large contact area and good polishing performance, a polishing solution prepared from the composite abrasive particle can be used for chemically and mechanically polishing materials such as titanium, aluminum, tungsten tantalum and quartz, the surface quality is high after polishing, and the material removal rate is high.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical mechanical polishing, and in particular relates to a composite abrasive particle and a preparation method thereof, and a polishing liquid. Background Art

[0002] Chemical mechanical polishing (CMP) is an ultra-precision machining technology that combines chemical oxidation and mechanical removal. This synergistic effect effectively reduces surface roughness and subsurface damage, improves material removal rates, and ultimately produces a smooth, flawless surface. Abrasive particles, as a key component of CMP polishing slurry, play a vital role in material removal, and their morphology, structure, size, and chemical composition significantly influence the final polishing performance.

[0003] Due to its high hardness and good stability, Al2O3 is widely used in the CMP of materials such as quartz, metal, sapphire, and silicon carbide. Although using Al2O3 for polishing can significantly improve material removal rates, under the action of electrostatic forces, Al2O3 abrasive particles in the polishing liquid easily agglomerate into large particle clusters, resulting in flocculation and stratification, resulting in poor stability of the polishing liquid and detrimental to the surface quality of the material. At the same time, due to the high hardness of Al2O3 abrasive particles, they easily produce micro-scratches on the workpiece surface during the CMP process. In addition, the morphology of Al2O3 abrasives also has a significant impact on the CMP process. Existing Al2O3 abrasives are mainly granular, which has high polishing pressure conditions and a relatively small contact area with the workpiece. Material removal rate and roughness still need to be improved. Summary of the Invention

[0004] The purpose of the present invention is to solve at least one problem in the prior art and to provide a composite abrasive particle, a preparation method thereof, and a polishing liquid.

[0005] To achieve the above object, the present invention proposes a method for preparing composite abrasive particles, comprising the following steps: Preparation of porous SiO2: Sodium silicate nonahydrate is added to anhydrous ethanol and deionized water, and stirred to obtain a mixed solution of sodium silicate nonahydrate; a template is added to the mixed solution of sodium silicate nonahydrate, and stirred to obtain a mixed solution; an acetic acid solution is added to the mixed solution for reaction, and the porous SiO2 is obtained after centrifugation, washing, drying, and calcination to remove the template; Preparation of composite abrasive grains: adding porous SiO2 and aluminum nitrate nonahydrate to anhydrous ethanol and deionized water, stirring to obtain a suspension; mixing an alkaline substance and deionized water with a precipitant solution in a mass ratio of (0.5-1):(5-6); adding the precipitant solution dropwise to the suspension and reacting at 80°C-90°C, and centrifugally cleaning the reaction product using a centrifuge; dissolving the reaction product after centrifugation in a mixed solution of n-butanol and water, and azeotropically drying the mixture under heating and stirring in an oil bath to obtain composite abrasive grains; The composite abrasive has porous SiO2 as its core and fibrous γ-Al2O3 as its shell. The droplet acceleration rate of the precipitant solution is 1.2 mL / min to 1.9 mL / min. The concentrations of the porous SiO2 and aluminum nitrate nonahydrate are 0.3 mol / L to 0.8 mol / L and 0.05 mol / L to 0.12 mol / L, respectively.

[0006] As an optional embodiment, the template agent is hexadecyltrimethylammonium chloride or hexadecyltrimethylammonium bromide, and the concentration of the template agent is 0.06 mol / L to 0.09 mol / L.

[0007] As an optional embodiment, the alkaline substance is at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, and ammonia monohydrate, and the concentration of the alkaline substance is 0.2 mol / L to 0.4 mol / L.

[0008] As an optional embodiment, the volume ratio of n-butanol and water in the preparation step of the composite abrasive is (6-7): (3-4), and the azeotropic drying includes the following two stages: the temperature of the first stage is 80°C to 90°C, and the holding time is 0.5h to 1.5h; the temperature of the second stage is 110°C to 120°C, and the holding time is 2h to 4h.

[0009] As an optional embodiment, in the preparation step of the composite abrasive, porous SiO2 and aluminum nitrate nonahydrate are added to anhydrous ethanol and deionized water and then ultrasonically stirred. The mass fraction ratio of anhydrous ethanol to deionized water is (1-3): (5-6), and the ultrasonic stirring time is 30 min to 40 min. After the precipitant solution is added dropwise to the suspension, stirring is carried out at 300 r / min to 400 r / min.

[0010] As an optional embodiment, in the preparation step of the porous SiO2, the mass ratio of anhydrous ethanol and deionized water is (2-3): (6-7), the concentration of sodium silicate nonahydrate is 0.1 mol / L-0.5 mol / L, and ultrasonic stirring is adopted after sodium silicate nonahydrate is added to anhydrous ethanol and deionized water, and the ultrasonic stirring time is 5 min-10 min.

[0011] As an optional embodiment, the concentration of the acetic acid solution in the preparation step of the porous SiO2 is 0.3 mol / L to 0.5 mol / L, the calcination is carried out in a muffle furnace, the temperature of the muffle furnace during the calcination process is 550°C to 600°C, the heating rate is 10°C / min to 20°C / min, and the holding time is 0.5h to 2h.

[0012] As an optional embodiment, in the preparation step of the porous SiO2, the sodium silicate nonahydrate mixed solution and the template are stirred in a constant temperature heating magnetic stirrer, the speed of the constant temperature heating magnetic stirrer is 500r / min~600r / min, and the temperature is 40℃~50℃.

[0013] The present invention also provides a composite abrasive particle prepared according to the above-mentioned method for preparing the composite abrasive particle.

[0014] The present invention also provides a polishing liquid containing 3 wt% to 10 wt% of the composite abrasive particles. In actual use, the content of the composite abrasive particles in the polishing liquid is set to any value between 3 wt% and 10 wt%, and can be specifically set according to the grinding requirements.

[0015] As an optional embodiment, the polishing liquid is composed of hydrogen peroxide, sodium bicarbonate, sodium tartrate, deionized water and the above-mentioned composite abrasive, the content of the composite abrasive in the polishing liquid is 3wt% to 10wt%, the content of hydrogen peroxide is 0.5wt% to 10wt%, wherein sodium bicarbonate is used as a pH regulator and sodium tartrate is used as a complexing agent.

[0016] The beneficial effects of the present invention are as follows: porous silica is prepared by a template method, and a layer of fibrous γ-Al2O3 is formed on the surface of the porous silica by using a chemical precipitation method and regulating the reaction rate. The entire preparation method is simple, the equipment is simple, and the safety is high; the prepared composite abrasive has porous SiO2 as a core and fibrous γ-Al2O3 as a shell; the porous SiO2 core can make the fibrous γ-Al2O3 have better deformation ability and improve the dispersibility of γ-Al2O3, thereby reducing mechanical damage during the polishing process and improving the surface quality after polishing; the fibrous γ-Al2O3 makes the composite abrasive have a shell with high hardness; compared with the granular Al2O3 morphology, the fibrous Al2O3 abrasive has a larger contact area with the workpiece material, increases the contact area between the abrasive and the workpiece material, is beneficial to improving the material removal rate, and has better polishing performance.

[0017] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a TEM image of the composite abrasive particles according to an embodiment of the present invention.

[0019] Figure 2 This is a high-magnification TEM image of the composite abrasive particles according to an embodiment of the present invention.

[0020] Figure 3 3 is the XRD pattern of the composite abrasive particles according to the embodiment of the present invention.

[0021] Figure 4 Graph showing the particle size distribution of porous SiO2 according to an embodiment of the present invention.

[0022] Figure 5 1 is a force-displacement curve of the composite abrasive particles according to an embodiment of the present invention and a Young's modulus fitting diagram thereof.

[0023] Figure 6 This is a three-dimensional surface profile diagram of titanium alloy, tungsten-tantalum alloy, aluminum alloy, and fused quartz material after being polished by composite abrasive particles according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0025] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention, its application, or use. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] Example 1 This embodiment provides a method for preparing composite abrasive particles, which specifically includes the following steps: Preparation of porous SiO2: 25 g of Na2SiO3·9H2O was weighed and added to 90 mL of anhydrous ethanol and 210 mL of deionized water, and ultrasonically stirred for 10 min to obtain a Na2SiO3·9H2O mixed solution; then 7 g of hexadecyltrimethylammonium bromide was weighed and added to the Na2SiO3·9H2O mixed solution, and then placed in a constant temperature heated magnetic stirrer, set the speed to 500 r / min, and the temperature to 50°C for stirring to obtain a mixed solution; 22 mL of 36% acetic acid was added to the above mixed solution and reacted for 3 h. After the reaction was completed, the suspension produced after the reaction was placed in a centrifuge at a speed of 6000 r / min and alternately washed with deionized water and anhydrous ethanol, and then dried in a constant temperature drying oven set at 70°C for 2 h. Finally, the dried reaction product was calcined in a muffle furnace at 550°C for 1 h to remove hexadecyltrimethylammonium bromide to obtain porous SiO2; Preparation of composite abrasive: 6 g of porous SiO2 and 3 g of Al(NO3)3·9H2O were weighed and added to 50 mL of anhydrous ethanol and 250 mL of deionized water, and ultrasonically stirred for 30 min to obtain a suspension. The suspension was placed in a constant temperature heating magnetic stirrer for standby use. The speed of the constant temperature heating magnetic stirrer was set to 300 r / min and the temperature was set to 80°C. 0.4 g of NaOH was weighed and dissolved in 40 mL of deionized water to prepare NaOH solution. The NaOH solution was then added dropwise to the above suspension at a drop rate of 1.3 mL / min. After the addition was completed, the temperature and speed of the constant temperature heating magnetic stirrer were kept unchanged and the reaction was continued for 2 h. After the reaction was completed, the reaction product was centrifuged and cleaned using a centrifuge at a speed of 4000 r / min. r / min; the product after centrifugal washing was dissolved in a mixed solution of 60 mL of n-butanol and 30 mL of water, and azeotropically dried under heating and stirring in an oil bath (the first stage temperature was 80°C, the holding time was 1 h, the second stage temperature was 110°C, and the holding time was 3 h) to obtain composite abrasive particles, which had porous SiO2 as the core and fibrous γ-Al2O3 as the shell.

[0028] Example 2 This embodiment provides a method for preparing composite abrasive particles, which specifically includes the following steps: Preparation of porous SiO2: 30 g of Na2SiO3·9H2O was weighed and added to 85 mL of anhydrous ethanol and 200 mL of deionized water, and ultrasonically stirred for 5 minutes to obtain a Na2SiO3·9H2O mixed solution; then 8 g of hexadecyltrimethylammonium chloride was weighed and added to the Na2SiO3·9H2O mixed solution, and then placed in a constant temperature heating magnetic stirrer, set the speed to 600 r / min, and stirred at a temperature of 40°C to obtain a mixed solution; 20 mL of 36% acetic acid was added to the above mixed solution to react for 3 hours. After the reaction was completed, the suspension produced after the reaction was placed in a centrifuge with a speed set to 7000 r / min and alternately washed with deionized water and anhydrous ethanol, and then dried in a constant temperature drying oven set at 70°C for 2 hours. Finally, the dried product was calcined in a muffle furnace at 600°C for 1 hour to remove the hexadecyltrimethylammonium chloride to obtain porous SiO2; Preparation of composite abrasive: 7 g of porous SiO2 and 3 g of Al(NO3)3·9H2O were weighed and added to 40 mL of anhydrous ethanol and 220 mL of deionized water, and ultrasonically stirred for 40 min to obtain a suspension. The suspension was placed in a constant temperature heating magnetic stirrer for standby use. The speed of the constant temperature heating magnetic stirrer was set to 400 r / min and the temperature was set to 85°C. 0.84 g of KOH was weighed and dissolved in 50 mL of deionized water to prepare a KOH solution. The KOH solution was then added dropwise to the suspension containing Al(NO3)3·9H2O and porous SiO2 at a dropping speed of 1.5 mL / min. After the addition was completed, the temperature and speed of the constant temperature heating magnetic stirrer were kept unchanged and the reaction was continued for 2 min. h; after the reaction is completed, the reaction product is centrifuged and cleaned using a centrifuge at a speed of 4000 r / min; the centrifuged product is dissolved in a mixed solution of 70 mL of n-butanol and 40 mL of water, and azeotropically dried under heating and stirring in an oil bath (the first stage temperature is 85°C, the holding time is 0.5 h, the second stage temperature is 115°C, the holding time is 4 h) to obtain composite abrasive particles, which have porous SiO2 as the core and fibrous γ-Al2O3 as the shell.

[0029] Example 3 This embodiment provides a method for preparing composite abrasive particles, which specifically includes the following steps: Preparation of porous SiO2: 35 g of Na2SiO3·9H2O was weighed and added to 90 mL of anhydrous ethanol and 220 mL of deionized water, and ultrasonically stirred for 8 minutes to obtain a Na2SiO3·9H2O mixed solution; then 6 g of hexadecyltrimethylammonium chloride was weighed and added to the Na2SiO3·9H2O mixed solution, and then placed in a constant temperature heating magnetic stirrer, set the speed to 550 r / min, and the temperature to 45°C for stirring to obtain a mixed solution; 25 mL of 36% acetic acid was added to the above mixed solution to react for 3 hours. After the reaction was completed, the suspension produced after the reaction was placed in a centrifuge set at a speed of 7000 r / min and was alternately washed with deionized water and anhydrous ethanol. The reaction product was then dried in a constant temperature drying oven set at 70°C for 2 hours. Finally, the dried product was calcined in a muffle furnace at 570°C for 1 hour to remove the hexadecyltrimethylammonium chloride to obtain porous SiO2; Preparation of composite abrasive: 6 g of porous SiO2 and 5 g of Al(NO3)3·9H2O were weighed and added to 60 mL of anhydrous ethanol and 250 mL of deionized water, and ultrasonically stirred for 40 min to obtain a suspension. The suspension was then placed in a constant temperature heating magnetic stirrer with a speed of 400 r / min and a temperature of 90°C. 0.9 g of Ca(OH)2 was weighed and dissolved in 60 mL of deionized water to prepare a Ca(OH)2 solution. The Ca(OH)2 solution was then added dropwise to the suspension containing Al(NO3)3·9H2O and porous SiO2 at a dropping speed of 1.8 mL / min. After the addition was completed, the temperature and speed of the constant temperature heating magnetic stirrer were kept unchanged and the reaction was continued for 2 h. After the reaction was completed, the reaction product was centrifuged and cleaned using a centrifuge at a speed of 4000 r / min. r / min; the centrifuged product was dissolved in a mixed solution of 60 mL of n-butanol and 40 mL of water, and azeotropically dried under heating and stirring in an oil bath (the first stage temperature was 90°C, the holding time was 1 h, the second stage temperature was 120°C, the holding time was 3 h) to obtain composite abrasive particles, which had porous SiO2 as the core and fibrous γ-Al2O3 as the shell.

[0030] Comparative Example 1 This comparative example provides a method for preparing granular aluminum oxide abrasive particles, comprising the following steps: 10 g of aluminum nitrate nonahydrate was weighed and dissolved in 200 ml of deionized water and 100 ml of anhydrous ethanol, and placed in a magnetic stirrer with heating and stirring, the temperature was set to 95°C, and the speed was 500 r / min; then 4 g of NaOH was dissolved in 30 ml of deionized water to prepare a NaOH solution, and the NaOH solution was directly added to the aluminum nitrate nonahydrate solution to react for 1 hour; the reaction product was centrifuged at a speed of 3500 r / min and dried to obtain granular γ-Al2O3 polishing abrasive.

[0031] Comparative Example 2 This comparative example provides a method for preparing fibrous aluminum oxide abrasive particles, comprising the following steps: 10 g of aluminum nitrate nonahydrate was weighed and dissolved in 200 ml of deionized water and 100 ml of anhydrous ethanol, and placed in a magnetic stirrer with heating and stirring. The temperature was set to 90 °C and the rotation speed was 500 r / min. Subsequently, 4 g of NaOH was dissolved in 30 ml of deionized water to prepare a NaOH solution, and the NaOH solution was added dropwise to the aluminum nitrate nonahydrate solution at a drop rate of 2 ml / min. After the addition was completed, the reaction was continued for 1 hour. The reaction product was centrifuged at a speed of 3500 r / min and dried to obtain fibrous γ-Al2O3 polishing abrasives.

[0032] Comparative Example 3 This comparative example provides a method for preparing composite abrasive particles, comprising the following steps: 32 g of Na2SiO3·9H2O was weighed and added to 100 mL of anhydrous ethanol and 150 mL of deionized water, and ultrasonically stirred for 7 minutes to obtain a Na2SiO3·9H2O mixed solution; then 6 g of hexadecyltrimethylammonium chloride was weighed and added to the Na2SiO3·9H2O mixed solution, and the mixed solution was placed in a constant temperature heating magnetic stirrer, and the speed of the constant temperature heating magnetic stirrer was set to 500 r / min and the temperature was set to 50°C to obtain a mixed solution; 25 mL of 36% acetic acid was added to the above mixed solution and reacted for 3 hours. After the reaction was completed, the suspension produced after the reaction was placed in a centrifuge and alternately washed with deionized water and anhydrous ethanol, and the product was further dried in a constant temperature drying oven, wherein the centrifuge speed was 6000 r / min, the temperature of the constant temperature oven was set to 70°C, and the drying time was 2 hours. Finally, the dried reaction product was calcined in a muffle furnace at 550°C for 1 hour to remove the hexadecyltrimethylammonium chloride to obtain porous SiO2; 6 g of porous SiO2 and 7 g of Al(NO3)3·9H2O were weighed and added to 60 mL of anhydrous ethanol and 250 mL of deionized water, and ultrasonically stirred for 40 min to obtain a suspension. The suspension was then placed in a constant temperature heating magnetic stirrer, and the speed of the constant temperature heating magnetic stirrer was set to 400 r / min and the temperature was set to 95°C. 7 g of NaOH was weighed and dissolved in 60 mL of deionized water to prepare a NaOH solution. The NaOH solution was then added dropwise to the suspension containing Al(NO3)3·9H2O and porous SiO2 at a dropwise speed of 10 mL / min. After the dropwise addition was completed, the temperature and speed of the constant temperature heating magnetic stirrer were kept unchanged and the reaction was continued for 2 h. After the reaction was completed, the reaction product was centrifuged and washed using a centrifuge at a speed of 4000 r / min. The centrifuged product was dissolved in 60 mL of n-butanol and 40 The mixed solution of 1 mL of water was azeotropically dried under heating and stirring in an oil bath (90 ° C in the first stage, holding time for 1 h, and 120 ° C in the second stage, holding time for 3 h) to obtain composite abrasive particles with porous SiO2 as the core and granular γ-Al2O3 as the shell.

[0033] 1. Comparative test of different abrasives on workpiece polishing performance Four groups of chemical mechanical polishing solutions were prepared and recorded as experimental group, control group 1, control group 2, and control group 3. The four groups of chemical mechanical polishing solutions were composed of the following components in percentage by mass: 5wt% abrasive, 2wt% hydrogen peroxide, 5wt% sodium bicarbonate, 1wt% sodium tartrate, and the balance deionized water. The pH of the chemical mechanical polishing solution was 8. The abrasives in the experimental group, control group 1, control group 2, and control group 3 were the composite abrasives of Example 1 (recorded as porous SiO2@fibrous γ-Al2O3 composite abrasives), the granular γ-Al2O3 polishing abrasives of Comparative Example 1, the fibrous γ-Al2O3 polishing abrasives of Comparative Example 2, and the composite abrasives of Comparative Example 3 (recorded as porous SiO2@fibrous γ-Al2O3 composite abrasives). Equal amounts of the four groups of chemical mechanical polishing solutions were taken, and the polishing pressure, speed, time, and polishing liquid flow rate of each group were 50 kPa, 60 rpm, 30 Titanium alloy, tungsten-tantalum alloy, aluminum alloy and fused quartz were polished using damping cloth material as the polishing pad under the polishing parameters of 8 ml / min and 12 ml / min. The surface roughness and material removal rate of titanium alloy, tungsten-tantalum alloy, aluminum alloy and fused quartz after polishing with each group of polishing liquid were observed. The specific observation results are shown in Table 1 below.

[0034] Table 1 Comparison of polishing performance of different abrasives

[0035] As shown in Table 1, the surface roughness Sa of titanium alloy, tungsten-tantalum alloy, aluminum alloy and fused quartz after polishing using the polishing liquid of the experimental group containing the composite abrasive (porous SiO2@fibrous γ-Al2O3) of the present application is within 50 × 50 μm. 2 The ranges of the polishing fluids are 0.20 nm, 0.22 nm, 0.25 nm, and 0.20 nm, respectively, and the material removal rates are 16.34 µm / h, 14.97 µm / h, 17.68 µm / h, and 3.12 µm / h, respectively. Compared with the control group polishing fluids containing granular γ-Al2O3, fibrous γ-Al2O3, and porous SiO2@granular γ-Al2O3 abrasives, the material removal rate is higher and the surface roughness is lower after polishing titanium alloy, tungsten-tantalum alloy, aluminum alloy, and fused quartz, indicating that the use of porous SiO2@fibrous γ-Al2O3 can improve the polishing performance.

[0036] 2. Performance test of composite abrasive (porous SiO2@fibrous γ-Al2O3 composite abrasive) The composite abrasive particles (porous SiO2@fibrous γ-Al2O3 composite abrasive particles) obtained in Example 1 were tested using a transmission electron microscope. Figure 1 The TEM images shown in Figure 2 TEM high magnification image shown. Figure 1 and Figure 2 It can be seen that the composite abrasive prepared in the present application is regular spherical with a particle size between 100 nm and 120 nm, and the outermost layer of the composite abrasive has a fiber morphology.

[0037] The composite abrasive particles (porous SiO2@fibrous γ-Al2O3 composite abrasive particles) obtained in Example 1 were tested using an X-ray diffractometer, and the following results were obtained: Figure 3 The XRD pattern shown by Figure 3 It can be seen that the phase composition of the composite abrasive prepared in this application is amorphous SiO2 and γ-Al2O3.

[0038] The particle size distribution of porous SiO2 in Example 1 was obtained by experiment (see Figure 4 The force displacement curves of composite abrasives (porous SiO2@fibrous γ-Al2O3 composite abrasives) and their Young's modulus fitting diagrams (as shown in Figure 5 ), by Figure 4 and Figure 5 It can be seen that the pore size of porous SiO2 is 3nm~4nm and the Young's modulus of the composite abrasive is 4.3 GPa, which makes the composite abrasive have better deformation ability and improves the surface quality of the workpiece.

[0039] Titanium alloy, tungsten-tantalum alloy, aluminum alloy, and fused quartz materials were polished using chemical mechanical polishing liquid. The chemical mechanical polishing liquid consisted of the following components in percentage by mass: 5wt% of the composite abrasive of Example 1 (recorded as porous SiO2@fibrous γ-Al2O3 composite abrasive), 2wt% of hydrogen peroxide, 5wt% of sodium bicarbonate, 1wt% of sodium tantalum, and the balance of deionized water. The pH of the chemical mechanical polishing liquid was 8, and the polishing parameters were as follows: polishing pressure, rotation speed, time, and polishing liquid flow rate were 50 kPa, 60 rpm, 30 min, and 8 ml / min, respectively. A damping cloth material was used as a polishing pad to polish the titanium alloy. The surfaces of the polished titanium alloy, tungsten-tantalum alloy, aluminum alloy, and fused quartz materials were observed. The results are as follows: Figure 6 shown.

[0040] Depend on Figure 6 It can be seen that the surfaces of titanium alloy, tungsten-tantalum alloy, aluminum alloy and fused quartz materials polished with the polishing liquid containing the composite abrasive of Example 1 (recorded as porous SiO2@fibrous γ-Al2O3 composite abrasive) are very smooth without obvious defects, and the surface roughness is within 50 × 50 μm. 2 The range is controlled within about 0.2 nm.

[0041] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. A method for preparing composite abrasive particles, characterized in that: The following steps are involved: Preparation of porous SiO2: Sodium silicate nonahydrate is added to anhydrous ethanol and deionized water, and stirred to obtain a mixed solution of sodium silicate nonahydrate; a template is added to the mixed solution of sodium silicate nonahydrate, and stirred to obtain a mixed solution; an acetic acid solution is added to the mixed solution for reaction, and the porous SiO2 is obtained after centrifugation, washing, drying, and calcination to remove the template; Preparation of composite abrasive grains: adding porous SiO2 and aluminum nitrate nonahydrate to anhydrous ethanol and deionized water, stirring to obtain a suspension; mixing an alkaline substance and deionized water with a precipitant solution in a mass ratio of (0.5-1):(5-6); adding the precipitant solution dropwise to the suspension and reacting at 80°C-90°C, and centrifugally cleaning the reaction product using a centrifuge; dissolving the reaction product after centrifugation in a mixed solution of n-butanol and water, and azeotropically drying the mixture under heating and stirring in an oil bath to obtain composite abrasive grains; The composite abrasive has porous SiO2 as its core and fibrous γ-Al2O3 as its shell. The droplet acceleration rate of the precipitant solution is 1.2 mL / min to 1.9 mL / min. The concentrations of the porous SiO2 and aluminum nitrate nonahydrate are 0.3 mol / L to 0.8 mol / L and 0.05 mol / L to 0.12 mol / L, respectively.

2. The method for preparing the composite abrasive according to claim 1, wherein: The template agent is hexadecyltrimethylammonium chloride or hexadecyltrimethylammonium bromide, and the concentration of the template agent is 0.06 mol / L to 0.09 mol / L.

3. The method for preparing the composite abrasive according to claim 1, wherein: The alkaline substance is at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, and ammonia monohydrate, and the concentration of the alkaline substance is 0.2 mol / L to 0.4 mol / L.

4. The method for preparing the composite abrasive according to claim 1, wherein: In the preparation step of the composite abrasive, the volume ratio of n-butanol to water is (6-7): (3-4), and the azeotropic drying includes the following two stages: the temperature of the first stage is 80°C to 90°C, and the insulation time is 0.5h to 1.5h; the temperature of the second stage is 110°C to 120°C, and the insulation time is 2h to 4h.

5. The method for preparing the composite abrasive according to claim 1, wherein: In the preparation step of the composite abrasive, porous SiO2 and aluminum nitrate nonahydrate are added to anhydrous ethanol and deionized water, and then ultrasonic stirring is adopted. The mass fraction ratio of anhydrous ethanol to deionized water is (1-3): (5-6), and the ultrasonic stirring time is 30 min to 40 min. After the precipitant solution is added dropwise to the suspension, stirring is carried out at 300 r / min to 400 r / min.

6. The method for preparing composite abrasive particles according to claim 1, wherein: In the preparation step of the porous SiO2, the mass ratio of anhydrous ethanol to deionized water is (2-3): (6-7), the concentration of sodium silicate nonahydrate is 0.1 mol / L-0.5 mol / L, and ultrasonic stirring is performed after the sodium silicate nonahydrate is added to anhydrous ethanol and deionized water, and the ultrasonic stirring time is 5 min-10 min.

7. The method for preparing composite abrasive particles according to claim 1, wherein: In the preparation step of the porous SiO2, the concentration of the acetic acid solution is 0.3 mol / L to 0.5 mol / L, and the calcination is carried out in a muffle furnace. During the calcination process, the temperature of the muffle furnace is 550°C to 600°C, the heating rate is 10°C / min to 20°C / min, and the holding time is 0.5h to 2h.

8. The method for preparing composite abrasive particles according to claim 1, wherein: In the preparation step of the porous SiO2, the sodium silicate nonahydrate mixed solution and the template are stirred in a constant temperature heating magnetic stirrer, the speed of the constant temperature heating magnetic stirrer is 500r / min~600r / min, and the temperature is 40℃~50℃.

9. Composite abrasive particles prepared according to the method for preparing composite abrasive particles according to any one of claims 1 to 8.

10. A polishing liquid, characterized in that: The polishing liquid contains 3 wt % to 10 wt % of the composite abrasive particles according to claim 9.

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