Conductive ceramic bearing ball, ball bearing, motor having bearing, hard disk drive, and polygon scanner

摘要

A conductive ceramic bearing ball made of composite ceramic and having a mixed microstructure of a silicon nitride phase and a titanium nitride phase. The content ratio of the silicon nitride phase to the titanium nitride phase is such that the conductive ceramic bearing ball has an average coefficient of linear expansion within a temperature range of 20° C.-100° C. of from 2x10-6/K to 5x10-6/K.