Dry Sliding Wear Behavior of Al2O3-TiC Ceramic Composites Added with Solid Lubricant CaF2 by Cold Pressing and Sintering

Abstract

The solid lubricant CaF2 was added in Al2O3/TiC ceramic composites to reduce the friction coefficient and improve the wear resistance of the latter. The Al2O3/TiC/CaF2 composites were prepared by cold pressing and sintering. Experiments on friction and wear properties were conducted using a wear-and-tear machine. The wear surfaces were observed by scanning electron microscopy and energy-dispersive spectroscopy. The wear resistance properties and self-lubricating effect of samples were analyzed. Results show that the Al2O3/TiC/CaF2 composites have a lower friction coefficient than the Al2O3/TiC ceramic composites subjected to the same processes. The good wear resistance of the Al2O3/TiC/CaF2 ceramic composites stems from the low friction coefficient and wear rate. These parameters have a self-lubricating effect on wear surfaces. The mechanism of wear resistance is that smooth self-lubricating films form when CaF2 is applied on wear surfaces. CaF2 particles spread on friction pairs and fill micropits, thereby improving and smoothening worn regions.