Silicon nitride combined silicon carbide material based on molten salt medium pore-forming and preparation method of material

The invention relates to a silicon nitride combined silicon carbide material based on molten salt medium pore-forming and a preparation method of the silicon carbide material. According to the technical scheme of the invention, the preparation method comprises the following steps: firstly mixing the following raw materials in percentage by weight: 10-35wt% of carbonate powder, 10-30wt% of chloride salt, 20-30wt% of silicon powder and 20-30wt% of silicon carbide powder; then adding sulfite paper pulp waste liquid accounting for 3-10wt% of the raw materials, stirring for 0.4-0.6h, carrying out press forming, and drying; and then sintering the mixture for 2-6h at the nitrogen atmosphere and under the condition with the temperature of 1000-1400 DEG C, naturally cooling, and soaking with water for 24-48h to prepare the silicon nitride combined silicon carbide material based on molten salt medium pore-forming. The embodiment of the invention has the characteristics of low synthetic temperature, low production cost and easiness in industrialization. The silicon nitride combined silicon carbide material based on molten salt medium pore-forming prepared by using the preparation method has excellent functions of heat preservation and storage, is also good in mechanical strength and long in service life and is capable of replacing the traditional thermal insulation material.