Tribological characteristics of Co-based plasma sprayed coating in extreme conditions

The purpose of this study was to investigate the friction and wear behavior of Co- based plasma sprayed coating under extreme conditions. Experiments were conducted using a high temperature pin-on-disk apparatus with uncoated Ni-based superalloy pins against Co- based coating co-sprayed with hBN as solid lubricant. The results showed that the coefficient of friction for this tribocouple decreased with increase in temperature. Ex situ cross-sectional analysis by means of optical microscopy and SEM revealed the formation of transferred material on the Ni-based pin. The thickness and composition of the transferfilm varied depending on the sliding condition and correlated well with the friction and wear behavior.