Observations on the Sliding Wear of Ceramics

Abstract

Modern design concepts for heat engines with increased thermal efficiency call for the utilization of ceramic components. In some applications, lubrication of these components will be difficult to maintain. Consequently, a need exists for an expanded understanding of the dry sliding wear behavior of ceramics. Sliding wear experiments were performed on several ceramic pairs from which wear rate data and information on the nature of the physical damage resulting from dry sliding were obtained. The wear evaluation was a pin-on-disk test. The test conditions included temperatures as high as 425°C, a surface velocity of 0.3 m/s, and a normal force of 9.0 N. Most of the specimens experienced moderate to severe damage. Damage characterized as mild wear was observed in a single room temperature test. The coefficient of friction for the damaged specimens ranged from 0.7 to 1.0, while this value was consistently 0.24 for the undamaged specimen. The implications of these results for wear mechanism are discussed.