Black silicon carbide for coating

Silicon carbide is composed of tetrahedral (structure) of carbon and silicon atoms with strong bonds in the crystal lattice. This produces a very hard and strong material. Silicon carbide is not attacked by any acids or alkalis or molten salts up to 800°C. In the air, SiC forms a protective silicon oxide coating at 1200°C and can be used up to 1600°C. The high thermal conductivity coupled with low thermal expansion and high strength gives this material exceptional thermal shock-resistant qualities. Silicon carbide ceramics with little or no grain boundary impurities maintain their strength to very high temperatures, approaching 1600°C with no strength loss. Chemical purity, resistance to chemical attack at temperature, and strength retention at high temperatures have made this material very popular.

The Benefits of Silicon Carbide for Coating

• SiC benefits include low density, high strength, low coefficient of thermal expansion, high thermal conductivity, good electrical properties, high decomposition temperature (4530 F), and excellent corrosion resistance (i.e. alkaline and acidic). SiC is the third hardest material after diamond and boron carbide, making it extremely valuable for wear applications. SiC materials are used in over 30 industries, including the aerospace, automotive, electronics, power, and chemical industries.
• Carbon composite materials (CCM) are finding more and more applications in the industry due to the strength, stiffness, and weight. However, they must be protected when in service due to the tendency of CCMs to degrade in alkaline and acidic environments and sunlight. SiC is an excellent choice for these coating applications due to the unique properties of SiC.
• SiC coatings are dense, hard, and wear-resistant. Porosity is less than 2%, hardness is 9.2 on the Mohs scale, bond strength exceeds 4000 Psia, and surface roughness is 145 microinches. SiC coatings can be deposited on steel, aluminum, graphite, silicon carbide, and carbon composites.