Trial Manufacture of Ceramic Ball Screw (2nd Report)

Life Test of Silicon Nitride and Sialon by Cylindrical Model

Abstract

In the 1st report, the applicability of alumina ceramics (Al₂O₃) to ball screws was studied by rolling fatigue life test using the simplified cylindrical model of ball screws. In this report, the applicability of silicon nitride (Si₃N₄) and Sialon (SiAlON) ceramics was also studied by the same method. It was clarified by the test that the surface roughness of both materials had influence on the life and the basic dynamic capacities of both materials were 10% of that of bearing steel (SUJ 2) when the test pieces had good surfaces. SEM observation made it clear that the fracture occurred at the outskirts of ceramics pores in the same process as the fracture of the alumina. As a result, the applicability order of 3 ceramics are the silicon nitride, Sialon and alumina.