Rolling-Contact Fatique Test of Ceramics at Elevated Temperature

Two types of rolling-contact fatigue test machines for ceramic bearings were constructed to investigate the rolling-contact fatique properties of ceramics at elevated temperature in air and vacuum atmospheres.An automatic measuring system of weared shape and wear volume was also constructed to investigate the rolling-contact wear process.The rolling-contact fatigue lives of ceramic bearings at room temperature were around 10^6 cycles when the maximum hertz stress was2.7 GPa，which was longer than that of ordinary metallic bearings.At a temperature of 500°C，the rolling-contact lives of the ceramics were almost equal to or one-tenth of those at room temperature.From the wear volume measurments，the wear volume per one cycle increased with increasing the maximum Hertz stress and test temperature.This tendency corresponded to the reduction in rolling-contact fatigue life.Wear damages gracually progressed with cycling.The rolling-contact fatigue tests in a clean vacuum of 10^&lt；-7&gt；Torr and upto a temperature of 1600°C can be done using the rolling-contact fatigue test machine made in the present study。

Two types of rolling-contact fatigue test machines for ceramic bearings were constructed to investigate the rolling-contact fatique properties of ceramics at elevated temperature in air and vacuum atmospheres. An automatic measuring system of weared shape and wear volume was also constructed to investigate the rolling-contact wear process.The rolling-contact fatigue lives of ceramic bearings at room temperature were around 10^6 cycles when the maximum hertz stress was 2.7GPa, which was longer than that of ordinary metallic bearings. At a temperature of 500゜C, the rolling-contact lives of the ceramics were almost equal to or one-tenth of those at room temperature.From the wear volume measurments, the wear volume per one cycle increased with increasing the maximum Hertz stress and test temperature. This tendency corresponded to the reduction in rolling-contact fatigue life. Wear damages gracually progressed with cycling.The rolling-contact fatigue tests in a clean vacuum of 10^<-7> Torr and upto a temperature of 1600゜C can be done using the rolling-contact fatigue test machine made in the present study.