Understanding wear mechanisms of TiSiCN/Zr(C)N coatings at elevated temperatures

Abstract TiSiCN/ZrN coating and TiSiCN/ZrCN coating were prepared using multi-arc ion plating technology. In this work, the composition, mechanical properties and wear properties at elevated temperatures of both coatings were investigated. XRD results show that both coatings are composed of Ti, Zr (C, N) phases. At elevated temperatures, TiSiCN/ZrCN coating exhibits a lower friction coefficient and slightly higher wear rate compared to TiSiCN/ZrN coating. The result is that the introduction of C plays the role of lubrication and friction reduction effect, but the more content carbon leads to increased brittleness of the coating, and cracks are prone to occur and propagate under the effect of thermal and mechanical coupling, thereby causing the wear rate of the coating increased. The increased brittleness of TiSiCN/ZrCN coating is confirmed via mechanical properties. Under high temperature wear, a thin oxide layer formed on both coatings surface acts as a glaze to impede wear and it would break down to form a transfer layer under period force. At 500 °C, TiSiCN/ZrN coating and TiSiCN/ZrCN coating display the mechanisms of adhesive wear and abrasive wear, respectively.