silicon nitride si3n4 thermocouple protection tubes  

Silicon Nitride (Si3N4) bonded silicon carbide (SiC) material is a new type of advanced refractory materials. Compared with silicon carbide product, the product has characteristics of small thermal expansion, high thermal conductivity, not easy to have thermal stress, good thermal shock resistance, corrosion resistance, extreme cold or heat, oxidation, high temperature creep resistant ability and easily made into products with high dimensional accuracy requirements in line. Silicon nitride combined silicon carbide products have very high strength for normal atmospheric temperature, and it remains almost the same time with the strength and hardness at high temperature 1200-1400C. with the difference of using atmosphere, the maximum safe operating temperature could reach 1650-1750C.