High strength silicon nitride combined silicon carbide material and method for preparing same

Abstract

The invention relates to the technical field of refractory materials, in particular to a high strength silicon nitride combined silicon carbide material and a method for preparing the same. The material comprises the following raw materials by weight percentage: 76 to 86 percent of SiC, 10 to 20 percent of Si, 0.1 to 1 percent of mixture of La2O3 and Y2O3 and 2 to 4 percent of calcium lignosulfonate paper pulp. The preparation method comprises the following steps of: weighing up the raw materials; mixing the raw materials into pug; pressing the pug into a green body; drying the green body the green body in a resistance furnace at a temperature of between 100 and 150 DEG C to obtain a biscuit; and baking the biscuit at a temperature of between 1,400 and 1,480 DEG C for 8 to 16 hours under nitrogen atmosphere to obtain the finished product. Compared with the prior art, the generation of beta-Si3N4 is promoted by means of rare earth oxides; and simultaneously, the ultrafine powder can promote the sintering so as to improve the performance of the product, in particular, the strength of the product reaches 300MPa which is 1.5-time higher of that of the similar product and is 3 times of that of the conventional silicon carbide similar product.

Description

[technical field] [0001] The invention relates to the technical field of refractory materials, in particular to a high-strength silicon nitride bonded silicon carbide material and a preparation method thereof. [Background technique] [0002] At present, most traditional silicon carbide products generally have insufficient physical and chemical properties, and the phenomenon of short life. Silicon nitride combined with silicon carbide materials usually use synthetic SiC particles to add industrial silicon powder, and pass N at high temperature. 2 gas, press 2N 2 +3Si→Si 3 N 4 Reaction, closely combined with SiC particles, this material is better than traditional silicon carbide materials in terms of chemical corrosion resistance, physical properties, mechanical strength, and wear resistance; at the same time, the heat conduction of high temperature performance is also good, so it has obtained Wide range of applications, such as blast furnace lining in the metallurgical ind...

AI Technical Summary

Problems solved by technology

[0002] At present, most traditional silicon carbide products generally have insufficient physical and chemical properties, and the phenomenon of short life. Silicon nitride combined with silicon carbide materials usually use synthetic SiC particles to add industrial silicon powder, and pass N at high temperature. 2 Gas, press 2N 2 +3Si→Si 3 N 4 Reaction, closely combined with SiC particles, this material is better than traditional silicon carbide materials in terms of chemical corrosion resistance, physical properties, mechanical strength and wear resistance; at the same time, the heat conduction of high temperature performance is also good, so it has obtained A wide range of applications, such as blast furnace lining in the metallurgical industry, aluminum electrolytic cells in the non-ferrous industry, burner nozzles in the chemical industry, and kiln furniture for various industrial kilns