silicon carbide is classified into pressureless sintered silicon carbide/ssic,reaction bonded silicon carbide/sic and ssic with carbon grains and sic with carbon grains with different chemical and physical properties.ssic+carbon grains means that the sintered silicon carbide matrix has plenty of tiny carbon grains dispersing and it is the same with sic +carbon grains.There is another material:QSSic with carbon grain mean ssic matrix has plenty of micropores with carbon grains dispersing.sic with carbon, ssic with carbon and QSSic with carbon are used to make dry gas mechanical seal rings or face or the seals which will work in a dry way because a good self-lubrication belong to carbon with small friction when the other materials run against them
