▎ 摘　　要

NOVELTY - A preparation method of nano-combined silicon carbide ceramic powder, involves (S1) adding silicon carbide powder to aqueous solution of ethanol, and stirring, (S2) adding ethyl orthosilicate into the silicon carbide mixed solution, continuously stirring, adding glacial acetic acid to adjust pH value, fully reacting, and drying to obtain nano-coated silicon carbide particles, adding carbon powder to the nano-coated silicon carbide particles, and mechanically stirring, (S4) adding polyvinyl alcohol to the silicon carbide mixed powder, mechanically stirring, mixing uniformly, sealing and leaving still to obtain silicon carbide micro-powder mixed material, (S5) granulating uniformly mixed powder to obtain silicon carbide particles, and drying to obtain silicon carbide particles, and (S6) putting the silicon carbide particles into a high temperature vacuum atmosphere furnace, heat-treating, cooling, putting into a muffle furnace, and heat-treating to obtain a finished product. USE - Preparation method of nano-combined silicon carbide ceramic powder used in high temperature corrosion resistance application, national defense military industry and special ceramics. ADVANTAGE - The sintering temperature is greatly reduced by adding silicon dioxide sol nano-combination method. The regenerated ceramic powder has high purity, low porosity and excellent use performance, which solves the problem of reuse of waste silicon carbide powder in ceramics. DETAILED DESCRIPTION - A preparation method of nano-combined silicon carbide ceramic powder, involves (S1) weighing a certain amount of silicon carbide powder, adding to the aqueous solution of ethanol under the condition of ultrasonic stirring, and continuously stirring for 1-2 hours to fully disperse, where the volume ratio of absolute ethanol and water in the aqueous solution of absolute ethanol is (1-3):1, and the volume ratio of the absolute ethanol to the mass ratio of silicon carbide micropowder is (0.2-1) ml:1 g, (S2) (S21) adding ethyl orthosilicate into the silicon carbide mixed solution of (S1) under the condition of ultrasonic stirring, where the mass ratio of silicon dioxide content in ethyl orthosilicate and silicon carbide in step (S1) is 3-7%, continuously stirring, adding glacial acetic acid to adjust the pH value to 1-3, fully reacting for 2-6 hours, and drying at 80-120degrees Celsius for 4-8 hours to obtain nano-coated silicon carbide particles, (S3) adding the carbon powder to the nano-coated silicon carbide particles, where the molar ratio of the carbon content of the carbon powder to the silicon content of the silicon dioxide sol in step (S21) is 1.2-2, and mechanically stirring for 1-2 hours to mix uniformly, (S4) adding polyvinyl alcohol to the silicon carbide mixed powder of step (S3), where the content of polyvinyl alcohol and the silicon carbide mixed powder in the step (S3) is 3-5%, mechanically stirring for 1-2 hours, mixing uniformly, sealing and leaving still for 5-10 hours to obtain silicon carbide micro-powder mixed material, (S5) pouring the uniformly mixed powder in step (S4) into a granulator, and granulating to obtain silicon carbide particles with uniform size and particle size of 10-200 m, and drying at 90-100degreesC for 1-2 hours to obtain silicon carbide particles with proper humidity, and (S6) putting the silicon carbide particles processed in the step (S5) into a high temperature vacuum atmosphere furnace, heat-treating at 1350-1500degreesC for 2-3 hours, cooling to room temperature, putting into a muffle furnace at 500-600degreesC, and heat-treating for 2-3 hours to obtain a finished product. An INDEPENDENT CLAIM is included for a nano-combined silicon carbide ceramic powder.