Tribological properties of micro-textured surfaces of ZTA ceramic nanocomposites under the combined effect of test conditions and environments

High-performance zirconia-toughened alumina (ZTA) ceramic nanocomposites are of great interest because of their wide application prospect and popularization value. This study aims to reveal the mechanism how micro-texture affects the tribological properties of ZTA nanocomposites under the combined effect of test conditions and environments. The understanding of such mechanisms will guide the optimum design of composite-lubrication structure on the surface of nano-ceramic. Three types of micro-dimples with different area densities were produced by solid-sate pulse Nd:YAG laser on the surface of ZTA. The friction properties and wear mechanism were studied. The results show that the tribological properties of ZTA nanocomposites can be improved significantly by optimizing the density of the micro-dimples. Specifically, under the dry environment, textured ZTA surfaces have lower and more stable coefficient of friction than untextured ZTA surfaces, especially at a higher sliding speed and higher load. The capture function of the micro-dimples is considered to weaken the abrasive wear of materials, thereby maintaining a stable frictional behavior. Furthermore, a relatively high dense micro-dimpled structure is prone to improve the tribology of the materials. In addition, it can be observed that the friction coefficient further decreased under deionized water lubrication and higher sliding speed because of the secondary lubricating effect. The friction coefficient can be reduced to below 0.4 when the density of the micro-dimples is about 34 %.302