Silicon carbide composite powder as well as preparation method and application thereof

Abstract

The invention discloses silicon carbide composite powder as well as a preparation method and application thereof. A granulation method of the silicon carbide composite powder comprises the following steps: (1) uniformly mixing beta-SiC micropowder with water and a dispersing agent in a mass ratio of (0.1-0.2) to 1 to (0.03-0.08), putting the mixture into a sand mill, and carrying out circularly grinding, so as to obtain nano-beta-SiC slurry, wherein the average grain diameter of the beta-SiC micropowder is not more than 1.5 micron; (2) adding micron-scale alpha-SiC and a bonding agent into the nano-beta-SiC slurry, and uniformly stirring, so as to obtain mixed slurry, wherein the mass of micron-scale alpha-SiC is 0.8-0.9 of the mass of the mixed slurry, and the mass of the bonding agent is 0.03-0.05 of the mass of the mixed slurry; and (3) conveying the mixed slurry into a spray granulation machine through a peristaltic pump, so as to obtain silicon carbide composite granulated powder. By introducing nano-scale beta-SiC, the sintering temperature can be decreased, the tenacity and strength of ceramic can be increased, and more importantly, nano-scale beta-SiC can be gradually converted into alpha-SiC in a uniform phase during the sintering, so that the stability of the use performance of the silicon carbide ceramic is not degraded.

Description

technical field [0001] The invention relates to the technical field of powder processing, in particular to a granulation method for micro-nano silicon carbide composite powder. Background technique [0002] Silicon carbide (Silicon Carbide, SiC) powder is often used to make silicon carbide ceramics because of its superior properties such as high strength, high hardness, corrosion resistance, high temperature oxidation resistance, and low thermal expansion coefficient. It is widely used in metallurgy, machinery, petroleum, and chemical industry. , microelectronics, aerospace, steel, automobiles and other fields. However, due to the strong covalent bonding of silicon carbide (covalent bonding accounts for 88%), its high-temperature diffusion coefficient is low, sintering is difficult to compact, and its mechanical properties are poor. At present, the sintering temperature of silicon carbide ceramics in the industry is generally as high as 2000 °C or more. How to minimize its...

AI Technical Summary

Problems solved by technology

In the existing method of preparing silicon carbide ceramics, the performance of silicon carbide ceramics prepared by hot pressing sintering is excellent, but the cost of hot pressing sintering is high and it is difficult to prepare silicon carbide ceramics with complex shapes

At present, there is no report on the preparation of micro-nano-scale silicon carbide composite granulated powder by combining nano-scale β-SiC and micro-scale α-SiC

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