FRICTION OF METAL SLIDERS ON TOUGHENED ZIRCONIA CERAMIC BETWEEN 298-K AND 973-K

This paper reports the results of an investigation of the coefficients of dynamic friction, in unlubricated conditions, of stainless and medium carbon steels, copper and aluminium sliders on a commercially available ceria stabilized, high toughness zirconia ceramic at temperatures up to 973 K. These sliding materials were selected to provide a range of chemical and physical properties representative of commercially available alloys. Measurements were made using 136-degrees apical angle metal cones against the polished zirconia ceramic in air, using a normal load of 3.9 N. The friction coefficients increased from about 0.1 at room temperature to greater than 0.5 at elevated temperatures. Optical and scanning electron microscopy, with energy-dispersive X-ray analysis, showed that the increase in the friction coefficient with increasing temperature was associated with the transfer of slider material onto the ceramic counterface.