Alumina-based high-dispersity grinding powder and preparation method thereof

Abstract

The invention discloses aluminum oxide-based high-dispersity grinding powder and a preparation method thereof, and relates to the technical field of aluminum oxide grinding powder. Comprising the following steps: step 1, adding aluminum chloride hexahydrate and aluminum nitrate nonahydrate into deionized water, adding a precipitator, a dispersant, ammonium fluoride and a functional additive, stirring at 85-95 DEG C for 3-4 hours, aging for 0.5-1.5 hours, washing and drying to obtain aluminum hydroxide powder; 2, grinding aluminum hydroxide powder and a sintering aid to obtain a raw material; and 3, calcining the raw materials in stages, and cooling to room temperature to obtain the high-dispersity grinding powder. The functional additive, the dispersing agent and other raw materials are combined with the sintering aid and a specific process to finally obtain the product; the system can effectively prevent carbonization of organic matters and inhibit abnormal growth of crystal grains, so that the dispersity and hardness of the product are remarkably improved while the crystal grain size of the product is controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alumina grinding powder, and particularly relates to a high-dispersibility alumina-based grinding powder and a preparation method thereof. BACKGROUND

[0002] Alumina grinding powder has high hardness, wear resistance and chemical stability, and is widely used in the fields of polishing, ceramics and semiconductors. The alumina grinding powder is usually obtained by calcination of a precursor such as aluminum hydroxide or alumina hydrate.

[0003] However, due to the strong van der Waals force between alumina grinding powders, the alumina is prone to agglomeration during preparation and application, and has poor dispersibility, which seriously affects the application of the alumina grinding powder. Therefore, the high dispersibility of the alumina grinding powder has become a hot research topic.

[0004] Patent CN116462490B mentions using a hybrid sol as a sintering aid powder to increase the grain nucleation and promote the distribution of the crystal state during calcination, so as to improve the dispersibility of the alumina grinding powder. However, the organic matter still has the risk of carbonization during calcination, which affects the performance of the final product. In addition, the sintering aid powder is usually physically mixed, and there is a lack of significant internal interaction between the components, so the synergistic performance is weak, and the performance of the alumina grinding powder is limited.

[0005] In view of the above, it is of great significance to prepare a high-dispersibility alumina-based grinding powder and a preparation method thereof. SUMMARY

[0006] The present application aims to provide a high-dispersibility alumina-based grinding powder and a preparation method thereof to solve the problems in the background art.

[0007] To solve the above technical problems, the present application provides the following technical solutions: A preparation method of a high-dispersibility alumina-based grinding powder, comprising the following steps: Step 1: aluminum chloride hexahydrate and aluminum nitrate nonahydrate are added to deionized water, a precipitating agent, a dispersing agent, ammonium fluoride and a functional additive are added, and stirring is performed at 85-95 DEG C for 3-4 hours, aging is performed for 0.5-1.5 hours, and washing and drying are performed to obtain aluminum hydroxide powder; Step 2: the aluminum hydroxide powder and a sintering aid are ground to obtain a raw material; Step 3: the raw material is calcined in stages, and cooled to room temperature to obtain a high-dispersibility grinding powder.

[0008] In a more optimized manner, the raw materials of the aluminum hydroxide powder, by mass parts, are: 2-3 parts aluminum chloride hexahydrate, 3.5-4 parts aluminum nitrate nonahydrate, 6-10 parts precipitant, 3-4 parts dispersant, 0.3-0.8 parts ammonium fluoride, and 0.5-0.8 parts functional additives.

[0009] More preferably, the precipitant is urea; the dispersant is a 20-30 wt% modified ammonium polyacrylate aqueous solution; and the functional additive is ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 1:(1-1.2).

[0010] A more optimized method for preparing the 20-30 wt% modified ammonium polyacrylate aqueous solution is as follows: S1-1: Cerium oxide and 3-(isobutenoyloxy)propyltrimethoxysilane were added to an aqueous ethanol solution and reacted at 60-80℃ for 3-5 h. After washing and drying, double bond modified cerium oxide was obtained. S1-2: Double-bond modified cerium oxide, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and polyethylene glycol monoallyl ether are added to deionized water. Ammonia is added to adjust the pH to 6.9-7.1. Ammonium persulfate and ammonium bisulfite are added at 70-75℃ and reacted at a constant temperature for 30-40 minutes. After cooling to room temperature, dilute ammonia is added to adjust the pH to 7.0-7.2 to obtain a 20-30 wt% modified ammonium polyacrylate aqueous solution.

[0011] In a further embodiment, the ammonia solution is 25-28 wt% ammonia solution, and the dilute ammonia solution is 5-10 wt% dilute ammonia solution.

[0012] In a more optimized manner, the raw materials of the 20-30 wt% modified ammonium polyacrylate aqueous solution contain, by mass parts: 0.5-1 parts double bond modified cerium oxide, 1.4-1.6 parts acrylic acid, 2-2.1 parts 2-acrylamido-2-methylpropanesulfonic acid, 1.8-2.3 parts polyethylene glycol monoallyl ether, 0.03-0.06 parts ammonium persulfate, and 0.03-0.06 parts ammonium bisulfite.

[0013] In a further embodiment, the mass ratio of cerium oxide to 3-(isobutyryloxy)propyltrimethoxysilane in the raw materials for the double bond modified cerium oxide is (8~12):1.

[0014] In a more optimized manner, the sintering aid comprises modified silica sol and silane-modified yttrium oxide in a mass ratio of (4~6):1; The modified silica sol is prepared by: S2-1: Allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile were added to tetrahydrofuran and reacted at 60-80°C for 3-5 h. After cooling to room temperature, the mixture was purified and dried to obtain trimethoxysilane containing β-diketone. S2-2: Add silica sol to an ethanol aqueous solution, adjust the pH to 4-5 with dilute sulfuric acid, add trimethoxysilane containing β-diketone, and react at 50-80℃ for 5-6 hours to obtain modified silica sol.

[0015] The preparation method of silane-modified yttrium oxide is as follows: yttrium oxide and aminosilane coupling agent are added to an aqueous ethanol solution and reacted at 60~80℃ for 3~5h. After washing and drying, silane-modified yttrium oxide is obtained; the mass ratio of yttrium oxide to aminosilane coupling agent is (8~12):1.

[0016] In a further embodiment, the dilute sulfuric acid is 5-15 wt% dilute sulfuric acid.

[0017] In a more optimized manner, the molar ratio of allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile in the raw material containing β-diketone trimethoxysilane is (1~1.05):1:(0.01~0.02). In the raw materials of the modified silica sol, the mass ratio of silica sol, trimethoxysilane containing β-diketone, and aqueous ethanol solution is 8~12:1:50~60.

[0018] In a further embodiment, the silane-modified yttrium oxide is obtained by modification with an aminosilane coupling agent.

[0019] In a more optimized manner, during the staged calcination process, in the first stage, the heating rate is 1~2℃ / min, the temperature is 80~120℃, and the time is 10~20min; in the second stage, the heating rate is 1~2.5℃, the temperature is 400~500℃, and the time is 80~120min; in the third stage, the heating rate is 3~5℃, the temperature is 1000~1200℃, and the time is 1.5~3h.

[0020] In a more optimized manner, the amount of the sintering aid introduced accounts for 1~2.5wt% of the raw material; the grinding time is 6~8h; the grinding balls are zirconia large balls and zirconia small balls in a mass ratio of 1:(2~3); the particle size of the zirconia large balls is 15~25mm; the particle size of the zirconia small balls is 5~15mm; the mass ratio of material to grinding balls is 1:20; and the rotation speed is 250~350r / min.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are: This application uses specific components such as functional additives and dispersants as raw materials to construct aluminum hydroxide powder, and combines specific sintering aids and a segmented calcination process to finally prepare a highly dispersible grinding powder based on alumina. This system can help prevent abnormal grain growth, enhance the steric hindrance and electrostatic repulsion between particles, thereby improving the dispersion performance while ensuring the strength of the grinding powder.

[0022] Firstly, in the preparation of aluminum hydroxide powder, ammonium polyacrylate is selected as a dispersant. To prevent subsequent carbonization from affecting product performance, the ammonium polyacrylate is modified by introducing cerium and sulfonic acid groups. While providing steric hindrance and electrostatic effects to enhance dispersion performance, the sulfonic acid groups lower the polymer decomposition temperature and provide an acidic catalytic environment. In synergy with cerium, they promote catalytic oxidation, thereby ensuring decomposition during sintering. This not only leaves no carbon residue and protects the performance of the ground powder, but also helps to further improve product dispersibility during sintering after degassing, ensuring product quality.

[0023] Secondly, ammonium fluorotitanate and ammonium fluorosilicate are selected as functional additives. During the precipitation process, they are hydrolyzed in situ to generate highly dispersed nano-TiO2 and SiO2 precursors. In the early stage of calcination, nano-TiO2 acts as a heterogeneous nucleation core, which can reduce the nucleation barrier of the γ-alumina to α-alumina phase transition, thereby reducing the phase transition temperature. Meanwhile, the amorphous silica produced by the decomposition of ammonium fluorosilicate works synergistically with sintering aids to further improve the dispersibility and strength of the product, and promote densification and phase transition. In addition, the above components, together with yttrium oxide and cerium oxide, can synergistically reduce the α-alumina phase transition temperature, enabling phase transition to be completed with lower energy consumption, and effectively inhibiting excessive grain growth, thereby improving product performance.

[0024] Finally, in the design of sintering aids, β-diketone groups were introduced by preparing modified silica sol. These groups have a strong chelating effect and can chelate metal ions such as aluminum, yttrium, and cerium, thereby improving the dispersion uniformity among the components. In addition, during the sintering process, this chelating effect can further guide the formation of stable nanoscale grain boundary pinning phases, thus synergistically improving the strength of the product. Detailed Implementation

[0025] 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.

[0026] It should be noted that the following proportions are by weight. There are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: cerium oxide with a particle size of 10 nm, purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.; polyethylene glycol monoallyl ether with a relative molecular mass of 400, purchased from Sanda Chemical Co., Ltd.; yttrium oxide with a particle size of 20 nm, purchased from Zhongke Keyou Co., Ltd.; zirconia macrospheres with a particle size of 20 mm, product number KD-ZR0200, purchased from Hunan Jinda Ceramic Materials Co., Ltd.; and zirconia microspheres with a particle size of 1 mm. The following raw materials were purchased from Shanghai Xinmao Precision Ceramics Technology Co., Ltd.: 0mm diameter, product number NA; acidic silica sol, purchased from Shijiazhuang Shuanglian Chemical Co., Ltd.; CAS number 4420-74-0 for 3-mercaptopropyltrimethoxysilane; CAS number 919-30-2 for aminosilane coupling agent 3-aminopropyltriethoxysilane; 20nm particle size of silica, purchased from Shanghai Naio Nanotechnology Co., Ltd.; rutile nano-titanium dioxide, 20nm particle size, purchased from Shanghai Naio Nanotechnology Co., Ltd.; and all other raw materials were commercially available.

[0027] Example 1: A method for preparing highly dispersible alumina-based grinding powder, comprising the following steps: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% modified ammonium polyacrylate aqueous solution), 0.5 parts of ammonium fluoride, and 0.65 parts of functional additive (ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 1:1.1), stir at 90℃ for 3.5 h, age for 1 h, wash and dry to obtain aluminum hydroxide powder; Step 2: Grind aluminum hydroxide powder and sintering aid (modified silica sol and silane-modified yttrium oxide in a mass ratio of 5:1) for 7 hours. The grinding balls are zirconia large balls and zirconia small balls in a mass ratio of 1:2.5; the particle size of the zirconia large balls is 20 mm and the particle size of the zirconia small balls is 10 mm; the mass ratio of material to grinding balls is 1:20; the rotation speed is 300 r / min. The raw material is obtained (the amount of sintering aid introduced accounts for 1.8 wt% of the raw material). Step 3: Calcine the raw materials in stages (in the first stage, the heating rate is 1.5℃ / min, the temperature is 100℃, and the time is 15min; in the second stage, the heating rate is 2℃, the temperature is 450℃, and the time is 100min; in the third stage, the heating rate is 4℃, the temperature is 1100℃, and the time is 2.5h), and cool to room temperature to obtain highly dispersible grinding powder; The preparation method of 25wt% modified ammonium polyacrylate aqueous solution is as follows: S1-1: 10 parts of cerium oxide and 1 part of 3-(isobutenoyloxy)propyltrimethoxysilane were added to a 60wt% aqueous ethanol solution and reacted at 70℃ for 4h. After washing and drying, double bond modified cerium oxide was obtained. S1-2: Add 0.8 parts of double bond modified cerium oxide, 1.5 parts of acrylic acid, 2.05 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 2.05 parts of polyethylene glycol monoallyl ether to deionized water, add 26 wt% ammonia to adjust the pH to 7.0, add 0.05 parts of ammonium persulfate and 0.05 parts of ammonium bisulfite at 72°C, react at a constant temperature for 35 min, cool to room temperature, add 8 wt% dilute ammonia to adjust the pH to 7.0, and obtain a 25 wt% modified ammonium polyacrylate aqueous solution; The preparation method of modified silica sol is as follows: S2-1: Allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile were added to tetrahydrofuran (the molar ratio of allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile was 1.02:1:0.015), reacted at 70°C for 4 h, cooled to room temperature, purified and dried to obtain trimethoxysilane containing β-diketone; S2-2: Add 10 parts of silica sol to 55 parts of 60wt% ethanol aqueous solution, add 10wt% dilute sulfuric acid to adjust the pH to 4.5, add 1 part of trimethoxysilane containing β-diketone, and react at 65℃ for 5.5h to obtain modified silica sol. The preparation method of silane-modified yttrium oxide is as follows: 10 parts of yttrium oxide and 1 part of aminosilane coupling agent (3-aminopropyltriethoxysilane) are added to a 60wt% ethanol aqueous solution, reacted at 70℃ for 4h, washed and dried to obtain silane-modified yttrium oxide.

[0028] Example 2: A method for preparing highly dispersible alumina-based grinding powder, comprising the following steps: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% modified ammonium polyacrylate aqueous solution), 0.5 parts of ammonium fluoride, and 0.5 parts of functional additive (ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 1:1), stir at 90℃ for 3.5 h, age for 1 h, wash and dry to obtain aluminum hydroxide powder; Step 2: Grind aluminum hydroxide powder and sintering aid (modified silica sol and silane-modified yttrium oxide in a mass ratio of 4:1) for 7 hours. The grinding balls are zirconia large balls and zirconia small balls in a mass ratio of 1:2.5; the particle size of the zirconia large balls is 20 mm, and the particle size of the zirconia small balls is 10 mm; the mass ratio of material to grinding balls is 1:20; and the rotation speed is 300 r / min. The raw material is obtained (the amount of sintering aid introduced accounts for 1 wt% of the raw material). Step 3: Calcine the raw materials in stages (in the first stage, the heating rate is 1.5℃ / min, the temperature is 100℃, and the time is 15min; in the second stage, the heating rate is 2℃, the temperature is 450℃, and the time is 100min; in the third stage, the heating rate is 4℃, the temperature is 1100℃, and the time is 2.5h), and cool to room temperature to obtain highly dispersible grinding powder; The preparation method of 25wt% modified ammonium polyacrylate aqueous solution is as follows: S1-1: 10 parts of cerium oxide and 1 part of 3-(isobutenoyloxy)propyltrimethoxysilane were added to a 60wt% aqueous ethanol solution and reacted at 70℃ for 4h. After washing and drying, double bond modified cerium oxide was obtained. S1-2: Add 0.8 parts of double bond modified cerium oxide, 1.5 parts of acrylic acid, 2.05 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 2.05 parts of polyethylene glycol monoallyl ether to deionized water, add 26 wt% ammonia to adjust the pH to 7.0, add 0.05 parts of ammonium persulfate and 0.05 parts of ammonium bisulfite at 72°C, react at a constant temperature for 35 min, cool to room temperature, add 8 wt% dilute ammonia to adjust the pH to 7.0, and obtain a 25 wt% modified ammonium polyacrylate aqueous solution; The preparation method of modified silica sol is as follows: S2-1: Allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile were added to tetrahydrofuran (the molar ratio of allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile was 1.02:1:0.015), reacted at 70°C for 4 h, cooled to room temperature, purified and dried to obtain trimethoxysilane containing β-diketone; S2-2: Add 10 parts of silica sol to 55 parts of 60wt% ethanol aqueous solution, add 10wt% dilute sulfuric acid to adjust the pH to 4.5, add 1 part of trimethoxysilane containing β-diketone, and react at 65℃ for 5.5h to obtain modified silica sol. The preparation method of silane-modified yttrium oxide is as follows: 10 parts of yttrium oxide and 1 part of aminosilane coupling agent (3-aminopropyltriethoxysilane) are added to a 60wt% ethanol aqueous solution, reacted at 70℃ for 4h, washed and dried to obtain silane-modified yttrium oxide.

[0029] Example 3: A method for preparing highly dispersible alumina-based grinding powder, comprising the following steps: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% modified ammonium polyacrylate aqueous solution), 0.5 parts of ammonium fluoride, and 0.8 parts of functional additive (ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 1:1.2), stir at 90℃ for 3.5 h, age for 1 h, wash and dry to obtain aluminum hydroxide powder; Step 2: Grind aluminum hydroxide powder and sintering aid (modified silica sol and silane-modified yttrium oxide in a mass ratio of 6:1) for 7 hours. The grinding balls are zirconia large balls and zirconia small balls in a mass ratio of 1:2.5; the particle size of the zirconia large balls is 20 mm and the particle size of the zirconia small balls is 10 mm; the mass ratio of material to grinding balls is 1:20; the rotation speed is 300 r / min. The raw material is obtained (the amount of sintering aid introduced accounts for 2.5 wt% of the raw material). Step 3: Calcine the raw materials in stages (in the first stage, the heating rate is 1.5℃ / min, the temperature is 100℃, and the time is 15min; in the second stage, the heating rate is 2℃, the temperature is 450℃, and the time is 100min; in the third stage, the heating rate is 4℃, the temperature is 1100℃, and the time is 2.5h), and cool to room temperature to obtain highly dispersible grinding powder; The preparation method of 25wt% modified ammonium polyacrylate aqueous solution is as follows: S1-1: 10 parts of cerium oxide and 1 part of 3-(isobutenoyloxy)propyltrimethoxysilane were added to a 60wt% aqueous ethanol solution and reacted at 70℃ for 4h. After washing and drying, double bond modified cerium oxide was obtained. S1-2: Add 0.8 parts of double bond modified cerium oxide, 1.5 parts of acrylic acid, 2.05 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 2.05 parts of polyethylene glycol monoallyl ether to deionized water, add 26 wt% ammonia to adjust the pH to 7.0, add 0.05 parts of ammonium persulfate and 0.05 parts of ammonium bisulfite at 72°C, react at a constant temperature for 35 min, cool to room temperature, add 8 wt% dilute ammonia to adjust the pH to 7.0, and obtain a 25 wt% modified ammonium polyacrylate aqueous solution; The preparation method of modified silica sol is as follows: S2-1: Allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile were added to tetrahydrofuran (the molar ratio of allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile was 1.02:1:0.015), reacted at 70°C for 4 h, cooled to room temperature, purified and dried to obtain trimethoxysilane containing β-diketone; S2-2: Add 10 parts of silica sol to 55 parts of 60wt% ethanol aqueous solution, add 10wt% dilute sulfuric acid to adjust the pH to 4.5, add 1 part of trimethoxysilane containing β-diketone, and react at 65℃ for 5.5h to obtain modified silica sol. The preparation method of silane-modified yttrium oxide is as follows: 10 parts of yttrium oxide and 1 part of aminosilane coupling agent (3-aminopropyltriethoxysilane) are added to a 60wt% ethanol aqueous solution, reacted at 70℃ for 4h, washed and dried to obtain silane-modified yttrium oxide.

[0030] Comparative Example 1: The dispersant (25wt% modified ammonium polyacrylate aqueous solution) was adjusted to 25wt% ammonium polyacrylate aqueous solution; the rest was the same as in Example 1; the specific differences are as follows: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% ammonium polyacrylate aqueous solution), 0.5 parts of ammonium fluoride, and 0.65 parts of functional additive (ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 1:1.1), stir at 90℃ for 3.5 h, age for 1 h, wash and dry to obtain aluminum hydroxide powder.

[0031] Comparative Example 2: The modified silica sol was changed to silica sol; the rest was the same as in Example 1; the specific differences are as follows: Step 2: Grind aluminum hydroxide powder and sintering aid (silica sol and silane-modified yttrium oxide in a mass ratio of 5:1) for 7 hours. The grinding balls are zirconia large balls and zirconia small balls in a mass ratio of 1:2.5. The particle size of the zirconia large balls is 20 mm and the particle size of the zirconia small balls is 10 mm. The mass ratio of material to grinding balls is 1:20. The rotation speed is 300 r / min. The raw material is obtained (the amount of sintering aid introduced accounts for 1.8 wt% of the raw material).

[0032] Comparative Example 3: No functional additives added; otherwise the same as Example 1; specific differences are as follows: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% modified ammonium polyacrylate aqueous solution), and 0.5 parts of ammonium fluoride. Stir at 90℃ for 3.5h, age for 1h, wash and dry to obtain aluminum hydroxide powder.

[0033] Comparative Example 4: No functional additives were added; silicon dioxide and titanium dioxide were directly added to the sintering aids; the rest was the same as in Example 1; the specific differences are as follows: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% modified ammonium polyacrylate aqueous solution), and 0.5 parts of ammonium fluoride. Stir at 90℃ for 3.5h, age for 1h, wash and dry to obtain aluminum hydroxide powder. Step 2: Grind aluminum hydroxide powder and sintering aid (modified silica sol, silane-modified yttrium oxide, silicon dioxide, and titanium dioxide in a mass ratio of 5:1:1:1) for 7 hours (grinding time: 7 hours; grinding balls: zirconia large balls and zirconia small balls in a mass ratio of 1:2.5; the particle size of the zirconia large balls is 20 mm, and the particle size of the zirconia small balls is 10 mm; the mass ratio of material to grinding balls is 1:20; the rotation speed is 300 r / min) to obtain raw material (the amount of sintering aid introduced accounts for 1.8 wt% of the raw material). Step 3: Calcine the raw materials in stages (in the first stage, the heating rate is 1.5℃ / min, the temperature is 100℃, and the time is 15min; in the second stage, the heating rate is 2℃, the temperature is 450℃, and the time is 100min; in the third stage, the heating rate is 4℃, the temperature is 1100℃, and the time is 2.5h), and cool to room temperature to obtain highly dispersible grinding powder.

[0034] Comparative Example 5: 25 wt% modified ammonium polyacrylate aqueous solution without double-bond modified cerium oxide; otherwise, it was the same as Example 1; the specific differences are as follows: The preparation method of 25wt% modified ammonium polyacrylate aqueous solution is as follows: S1-1: Add 1.5 parts acrylic acid, 2.05 parts 2-acrylamido-2-methylpropanesulfonic acid, and 2.05 parts polyethylene glycol monoallyl ether to deionized water, add 26 wt% ammonia to adjust the pH to 7.0, add 0.05 parts ammonium persulfate and 0.05 parts ammonium bisulfite at 72°C, react at a constant temperature for 35 min, cool to room temperature, add 8 wt% dilute ammonia to adjust the pH to 7.0, and obtain a 25 wt% modified ammonium polyacrylate aqueous solution.

[0035] Comparative Example 6: The amount and mass ratio of the functional additives were adjusted; the rest was the same as in Example 1; the specific differences are as follows: Step 1: Add 2.5 parts of aluminum chloride hexahydrate and 3.8 parts of aluminum nitrate nonahydrate to deionized water, add 8 parts of precipitant (urea), 3.5 parts of dispersant (25wt% modified ammonium polyacrylate aqueous solution), 0.5 parts of ammonium fluoride, and 2.4 parts of functional additives (ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 3:1), stir at 90℃ for 3.5 h, age for 1 h, wash and dry to obtain aluminum hydroxide powder.

[0036] Performance Test 1: The highly dispersible grinding powders prepared in Examples 1-3 and Comparative Examples 1-6 were tested for flowability using the pour point method to assess their dispersibility. A lower pour point indicates better dispersibility. Simultaneously, the particle size and hardness of the products were measured using a Mohs hardness comparator. The test results are shown in Table 1. Table 1

[0037] Conclusion: The data in the table above show that the highly dispersed grinding powder prepared in this application has high dispersibility, small grain size, and high hardness. According to the data in Comparative Example 1, adjusting the dispersant (25wt% modified ammonium polyacrylate aqueous solution) to 25wt% ammonium polyacrylate aqueous solution, which lacks cerium elements and sulfonic acid groups, easily leads to carbonization during subsequent sintering, severely affecting overall performance, and significantly reducing dispersibility and hardness. According to the data in Comparative Example 2, adjusting the modified silica sol to silica sol, which lacks β-diketone chelating groups, reduces dispersibility with other components and lowers overall performance. According to the data in Comparative Example 3, without functional additives, the phase transformation temperature increases and the grains become coarse. According to the data in Comparative Example 4, without functional additives, adding dioxide directly to the sintering aid... Silicon and titanium dioxide exhibit low heterogeneous nucleation efficiency and numerous defects, leading to a decline in overall performance. Data from Comparative Example 5 shows that without double-bond modified cerium oxide in a 25wt% modified ammonium polyacrylate aqueous solution, the catalytic oxidation function of cerium is lacking, resulting in decreased anti-carbonization performance, reduced grain refinement performance, and overall performance degradation. Data from Comparative Example 6 indicates that adjusting the amount and mass ratio of functional additives leads to an excess of ammonium fluorotitanate, which in turn causes an excess of titanium dioxide, resulting in agglomeration and grain growth. Simultaneously, an excessive amount of functional additives leads to an excess of fluorine, which excessively corrodes grain boundaries, accelerating grain boundary migration and further degrading overall performance.

[0038] 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 method for preparing highly dispersible alumina-based grinding powder, characterized in that: Includes the following steps: Step 1: Add aluminum chloride hexahydrate and aluminum nitrate nonahydrate to deionized water, add precipitant, dispersant, ammonium fluoride and functional additives, stir at 85~95℃ for 3~4h, age for 0.5~1.5h, wash and dry to obtain aluminum hydroxide powder; Step 2: Grind aluminum hydroxide powder and sintering aid to obtain raw materials; Step 3: Calcine the raw materials in stages and cool them to room temperature to obtain highly dispersible grinding powder.

2. The method for preparing a highly dispersible alumina-based grinding powder according to claim 1, characterized in that: The raw materials for the aluminum hydroxide powder, by mass parts, are: 2-3 parts aluminum chloride hexahydrate, 3.5-4 parts aluminum nitrate nonahydrate, 6-10 parts precipitant, 3-4 parts dispersant, 0.3-0.8 parts ammonium fluoride, and 0.5-0.8 parts functional additives.

3. The method for preparing a highly dispersible alumina-based grinding powder according to claim 1, characterized in that: The precipitant is urea; the dispersant is a 20-30 wt% modified ammonium polyacrylate aqueous solution; the functional additive is ammonium fluorotitanate and ammonium fluorosilicate in a mass ratio of 1:(1-1.2).

4. The method for preparing a highly dispersible alumina-based grinding powder according to claim 3, characterized in that: The preparation method of the 20~30wt% modified ammonium polyacrylate aqueous solution is as follows: S1-1: Cerium oxide and 3-(isobutenoyloxy)propyltrimethoxysilane were added to an aqueous ethanol solution and reacted at 60-80℃ for 3-5 h. After washing and drying, double bond modified cerium oxide was obtained. S1-2: Double-bond modified cerium oxide, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and polyethylene glycol monoallyl ether are added to deionized water. Ammonia is added to adjust the pH to 6.9-7.

1. Ammonium persulfate and ammonium bisulfite are added at 70-75℃ and reacted at a constant temperature for 30-40 minutes. After cooling to room temperature, dilute ammonia is added to adjust the pH to 7.0-7.2 to obtain a 20-30 wt% modified ammonium polyacrylate aqueous solution.

5. The method for preparing a highly dispersible alumina-based grinding powder according to claim 4, characterized in that: The raw materials for the 20-30 wt% modified ammonium polyacrylate aqueous solution include, by mass parts: 0.5-1 parts double bond modified cerium oxide, 1.4-1.6 parts acrylic acid, 2-2.1 parts 2-acrylamido-2-methylpropanesulfonic acid, 1.8-2.3 parts polyethylene glycol monoallyl ether, 0.03-0.06 parts ammonium persulfate, and 0.03-0.06 parts ammonium bisulfite.

6. The method for preparing a highly dispersible alumina-based grinding powder according to claim 5, characterized in that: The sintering aid comprises modified silica sol and silane-modified yttrium oxide in a mass ratio of (4~6):1; The modified silica sol is prepared by: S2-1: Allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile were added to tetrahydrofuran and reacted at 60-80°C for 3-5 h. After cooling to room temperature, the mixture was purified and dried to obtain trimethoxysilane containing β-diketone. S2-2: Add silica sol to an ethanol aqueous solution, adjust the pH to 4-5 with dilute sulfuric acid, add trimethoxysilane containing β-diketone, and react at 50-80℃ for 5-6 hours to obtain modified silica sol.

7. The method for preparing a highly dispersible alumina-based grinding powder according to claim 6, characterized in that: In the raw material containing β-diketone trimethoxysilane, the molar ratio of allyl acetoacetate, 3-mercaptopropyltrimethoxysilane, and azobisisobutyronitrile is (1~1.05):1:(0.01~0.02). In the raw materials of the modified silica sol, the mass ratio of silica sol, trimethoxysilane containing β-diketone, and aqueous ethanol solution is 8~12:1:50~60.

8. The method for preparing a highly dispersible alumina-based grinding powder according to claim 1, characterized in that: In the staged calcination process, in the first stage, the heating rate is 1~2℃ / min, the temperature is 80~120℃, and the time is 10~20min; in the second stage, the heating rate is 1~2.5℃, the temperature is 400~500℃, and the time is 80~120min; in the third stage, the heating rate is 3~5℃, the temperature is 1000~1200℃, and the time is 1.5~3h.

9. The method for preparing a highly dispersible alumina-based grinding powder according to claim 1, characterized in that: The amount of the sintering aid introduced accounts for 1~2.5wt% of the raw material; the grinding time is 6~8h, the grinding balls are zirconia large balls and zirconia small balls in a mass ratio of 1:(2~3); the particle size of the zirconia large balls is 15~25mm, and the particle size of the zirconia small balls is 5~15mm; the mass ratio of material to grinding balls is 1:20; the rotation speed is 250~350r / min.

10. The highly dispersible grinding powder prepared by the method for preparing highly dispersible grinding powder based on alumina according to any one of claims 1 to 9.

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