Effect of regular surface textures generated by laser on tribological behavior of Si_3N_4/TiC ceramic

摘要

Two kinds of regular micro-grooved textures with different geometric characteristics were fabricated on the surfaces of Si_3N_4/TiC ceramics by Nd:YAG laser; friction and wear tests were carried out to investigate the tribological properties of these textured ceramics in unlubricated and MoS_2 lubricated conditions. The wear surfaces of the textured ceramics and the balls were examined by SEM and the possible friction reduction and wear resistant mechanisms were discussed. The results show that the friction coefficient of the textured ceramics was reduced compared with the smooth ceramics among all the experiments, the wavy grooves are the most effective in the friction-reduction among the patterns investigated, and the wear life of textured ceramics can be increased in MoS_2 lubricated condition. Furthermore, it is observed that the textured ceramics produce more abrasive wear on the ball specimens in unlubricated friction, while it reduces the wear of balls in MoS_2 lubricated condition. The main effect mechanism of textures is to capture debris and reduces the contact area of couples in unlubricated condition, and increase lubricant supply by reservoir creation and form the continued lubricating film on the surfaces of spacing between the textures in MoS_2 solid lubricated condition.