Ssic and sic/silicon carbide have the property of excellent resistant-corrosion,high mechanical strength,high thermal conductivity,good self-lubrication,used as seal faces,bearings and tubes in spacecraft,machinery,metallurgy,printing and dyeing,foodstuff,phamaceutical,auto industry and so on.When the sic/silicon carbide faces are combined with graphite faces the friction is the smallest and they can be made into mechanical seals which are able to work in highest working requirements.

   the silicon carbide/sic materials for mechanical seal rings or faces are listed with different chemical and physical property shown in the following table:Reaction bonded silicon carbide/rbsic, pressureless sintered silicon carbide/ssic,rbsic + carbon/code M,silicon carbide/sic matrix with plenty of tiny carbon grains dispersing,Ssic + carbon/code M,ssic matrix with plenty of tiny carbon grains dispersing ,QSSic+ carbon/code M,ssic matrix with plenty of micropores with tiny carbon grains dispersing.Rbsic,+ carbon, ssic +carbon and QSSic+ 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 them with small friction when the other materials run together with mechanical seal rings in such materials