Method for preparing silicon carbide bonded silicon nitride composite material by using microwave sintering process

Abstract

The invention relates to a method for preparing a silicon carbide bonded silicon nitride composite material by using a microwave sintering process. The method is characterized by comprising the following steps: mixing the following components in percentage by weight: 50-80 percent of silicon carbide particles, 5-25 percent of silicon carbide powder, 5-30 percent of silicon powder, 1-4 percent of carboxymethyl cellulose and 1-5 percent of water, and molding; putting a molded blank body into a vacuum microwave sintering furnace, vacuumizing until the pressure intensity in the microwave sintering furnace is less than or equal to 20Pa, filling nitrogen, and sintering for 0.5-5 hours in a nitrogen atmosphere at 1300-1600 DEG C so as to obtain the silicon carbide bonded silicon nitride composite material. The method is short in production cycle and high in production efficiency; and the prepared silicon carbide bonded silicon nitride composite material is uniform in phase distribution and relatively high in strength, and has excellent thermal shock resistance, oxidation resistance, high-temperature creep resistance and erosion resistance.

Description

technical field [0001] The invention belongs to the technical field of silicon nitride combined with silicon carbide composite materials. In particular, it relates to a method for preparing a silicon nitride bonded silicon carbide composite material by a microwave sintering method. Background technique [0002] The microhardness of silicon nitride and silicon carbide is second only to a few superhard substances such as diamond, cubic boron nitride, and boron carbide. In addition, silicon carbide has excellent thermal conductivity and low thermal expansion rate, making silicon nitride Combined with silicon carbide composite material has excellent thermal shock resistance. At the same time, silicon nitride combined with silicon carbide has excellent chemical properties and can withstand the corrosion of almost all inorganic acids (except hydrofluoric acid) and some alkalis. In industrial applications, silicon nitride combined with silicon carbide resists the erosion of molte...

AI Technical Summary

Problems solved by technology

During use, there is a difference in the volume expansion coefficient between the interior and exterior of the composite material, which will cause problems such as spalling and cracking of the material during thermal cycling