Features of Silicon Nitride
Silicon nitride is an important structural ceramic material. It is a super hard material, with lubricity itself and wear resistance as an atomic crystal, as well as oxidation resistance at high temperature. And it can also be resistant to thermal shock. When heated to 1 000 ℃ or above in air, then rapidly cooled and sharply heated, it will not shatter.
Application of Silicon Nitride
Silicon nitride is suitable for advanced refractories. Silicon nitride ceramic materials have such excellent properties as high thermal stability, strong oxidation resistance and high accuracy for the product size. Since silicon nitride is a covalent compound with high bond strength, and can form an oxide protective film in air, it also has good chemical stability. Below 1200 ℃, it cannot be oxidized; at 1200 ~ 1600 ℃, it can form a protective film to prevent further oxidation. And it cannot be infiltrated or corroded by aluminum, lead, tin, silver, brass, nickel, and many other kinds of molten metal or alloy, but can be corroded by magnesium, nickel-chromium alloy, stainless steel and other melts.
Silicon nitride ceramic material can be used for components in high temperature engineering, refractories in the metallurgical industry and other aspects, corrosion-resistant members and sealing elements in the chemical industry, and cutting tools in the machining industry.
Since silicon nitride can form strong binding with silicon carbide, aluminum oxide, and thorium dioxide, it can be used as the bonding material, modified in different ratios.