SLIDING FRICTION AND WEAR OF STRUCTURAL CERAMICS .1. ROOM-TEMPERATURE BEHAVIOR

A study has been made of the unlubricated sliding friction and wear behavior of various like and unlike combinations of four materials - sintered alpha -SiC, graphitized SiC, siliconized SiC and a Y//2O//3-stabilized ZrO//2 - in air at room temperature under dynamic conditions approximating the motion of a piston in the cylinder of an idling automotive engine. The steady state friction coefficient is largely independent of the initial surface finish, but is in all cases unacceptably high for engine applications. The results suggest that ceramic components will not be used unlubricated in reciprocating situations.