Friction and wear behavior of Ti(C,N) self-lubricating cermet materials with multilayer core-shell microstructure

Abstract

In order to promote the friction and wear properties of cermet materials, an advanced Ti(C,N) self-lubricating cermet materials with the addition of ceramic coated nano-sized solid lubricant powders (CaF2@Al2O3) was developed. The friction and wear properties of Ti(C,N) self-lubricating cermet materials were studied by spherical disk matching. Results showed that the optimal content of CaF2@Al2O3 powders was 10 vol%, and the addition of CaF2@Al2O3 powders significantly reduced the friction coefficient of cermet. Meanwhile, the multilayer core-shell microstructure can significantly improve the wear resistance of Ti(C,N) based cermet. The higher temperature on the friction contact area made CaF2 change from brittle state to plastic state, which was evenly coated on the friction surface to form the self-lubricating film. On the one hand, as the load increased, the friction coefficient of cermet with multilayer core-shell microstructure decreased, but the wear rate increased. On the other hand, as the friction speed increased, the friction coefficient first increased slightly, then decreased gradually, and then continues to increase after decreasing to the minimum value. Besides, the wear rate first decreased and then increased with the increase of speed. The formation of multilayer core-shell microstructure has good wear-resistance effects on Ti(C,N) cermet, and the decrease of friction coefficient is mainly due to the addition of CaF2.