Pressureless sintering silicon carbide and preparation process thereof

Abstract

Pressureless sintering silicon carbide comprises the following components by mass: 80% to 90% of silicon carbide, 6% to 9% of resin, 0.5% to 0.8% of boron carbide, and the balance release agent. The preparation process for processing the pressureless sintering silicon carbide includes first stirring raw materials for 15 to 25 hours through a powder mixing machine to completely mix the raw materials, conducting spraying pelleting on the raw materials in the material mixing machine, forming powder materials after pelleting in press mode through a press, then filling the powder materials into a sintering furnace, conducting vacuumizing to -0.01MPA, stopping vacuumizing when the temperature rises to 1200 DEG C, filling argon into the sintering furnace to the normal pressure, then enabling temperature to rise to 1800 DEG C, keeping warm for 30 minutes, then continuously enabling the temperature to rise to the range from 2150 DEG C to 2200 DEG C, keeping warm for 30 to 50 minutes and enabling the powder materials to be naturally cooled. Due to the fact that fine powder materials are selected, compression density of product green bodies is improved, resin content is adjusted, the silicon carbide powder materials can conduct chemical reaction more fully in the sintering process, the density can reach 3.18g / cm<3>, and the hardness can reach 2400 HV0.5. The pressureless sintering silicon carbide has better abrasion resistance due to the fact that the density, the hardness and the compression strength are all improved.

Description

technical field [0001] The invention relates to a silicon carbide, in particular to a normal-pressure sintered silicon carbide and a manufacturing process thereof. Background technique [0002] Due to its stable chemical properties, high thermal conductivity, small thermal expansion coefficient, and good wear resistance, silicon carbide has many other uses besides being used as an abrasive. The inner wall can improve its wear resistance and prolong the service life by 1 to 2 times; the high-grade refractory material used to make it is heat-shock resistant, small in size, light in weight and high in strength, and has a good energy-saving effect. Low-grade silicon carbide (containing about 85% SiC) is an excellent deoxidizer, which can speed up steelmaking and facilitate the control of chemical composition to improve the quality of steel. In addition, silicon carbide is also widely used to make silicon carbide rods for electric heating elements. Silicon carbide is very hard ...

AI Technical Summary

Problems solved by technology

[0004] The problem to be solved by the present invention is to improve the product density of normal pressure sintered silicon carbide in the background technology is not high, resulting in insufficient strength and poor wear resistance