Experimental studies on friction and scuffing resistance of ceramics for cylinder linear and piston ring

The present paper refers to the experimental studies on tribological characteristics of lubricated ceramics for cylinder liners and piston rings. The experiments have been carried out under the large sliding velocity condition close to that of practical engines with pin-on-disk-type reciprocative slide test equipment. The major results are that: (i) for the materials, it is desirable that the sliding surface get a moderate running-in under the more elastic contact condition, and that the liner and the ring be superior in thermal diffusibility and in heat resistance, respectively; (ii) the respective influences of roughness and velocity on the scuffing are so large that the roughness should be kept smaller at the faster slide; and (iii) the effects of additives in mineral oil on the lubricity and the scuffing resistance disappear, and the contaminated oil has worse influences on both, thus it is necessary to select the proper lubricants.