Plain bearing Steel AISI52100 (GCR15), stainless steel AISI440 (9Cr18), silicon nitride (Si3N4) and Zirconia (ZrO2) Four kinds of bearing materials performance control, ceramic bearings as an important mechanical foundation, because of its metallic bearings can not match the excellent performance, high-temperature, super and so on in the new material world lead. In the past more than 10 years, in various areas of the livelihood of the increasingly widespread application.