As Si3N4 ceramic powder has good mechanical properties, chemical stability, low density and high temperature performance, the high-speed ball bearings made from high-purtity Si3N4 micropowder are widely used in sliding, rolling under high-contant stress(bearing, ball etc)

Because of their low weight,high hardness, little linear expansion coefficient, high modulus of elasticity, insulation, corrosion resistant(its density is only 40 percent of steel, hardness is 2.5 times of steel, expansion coefficient is only 25 percent of steel and elastic modulus is 1.5 times of steel), they have a great superiority compared with common steel ball-bearings under high-speed, high temperature, low temperature, high stiffness, high vacuum, corrosive media and so on special condition.