Tribological properties of TiAI-Ag-ZnO self-lubricating composites from room temperature to 800 degrees C

Tribological properties and lubricating mechanisms of TiAl-Ag-ZnO self-lubricating composites (TAZ) against A1(2)O(3) ball are studied from room temperature (RT) to 800 degrees C under a constant load of 10N and a constant speed of 0.2 ms(_1). It is found that TAZ obtains the lower friction coefficients and smaller wear rates, if compared with TiAl alloys (T). Solid lubricant Ag achieves a good lubricating effect by forming smooth Ag-rich lubricating film on the worn surfaces of TAZ bellow 400 degrees C. While from 600 to 800 degrees C, the formed ZnO-rich lubricating film on the worn surfaces is beneficial to improving the tribological performance of TAZ. It can draw a conclusion that TAZ obtains the excellent tribological properties over a wide temperature range because of the synergistic effect of Ag and ZnO.