Tribological properties of a Zr₂Al₃C₄ ceramic at ambient temperature

In this work, reciprocating ball-on-flat sliding friction and wear tests as well as two-body abrasive wear tests were performed on Zr₂Al ₃C₄, a new type of ceramic material. In the sliding wear tests, a Si₃N₄ ball and an AISI 52100 steel ball were used as counter materials. When Zr₂Al₃C₄ was slid against an AISI 52100 ball, the coefficient of friction (COF) was as low as 0.20-0.42, being independent of normal loads, and the wear rates of Zr ₂Al₃C₄ and AISI 52100 steel were in the range of 10^-4-10^-5 mm³/m. A tribofilm between the tribopair was presumed to be responsible for the low COF and wear rate. According to Raman and energy-dispersive spectroscopy analysis, the tribofilm consists of a mixture of oxides of Zr, Al, and Fe as well as amorphous carbon. When Zr₂Al₃C₄ was slid against a Si ₃N₄ ball, a transition from mild wear to severe wear was observed as the normal load increased. The transition occurs under certain contact stresses after a damage-accumulating period. In the two-body abrasive wear test, surface chipping and fragmentation resulting from coalescence of surface and subsurface microcracks were the main material removal mechanisms of Zr₂Al₃C₄.