Microstructure, mechanical and electrochemical properties of Ti3AlC2 coatings prepared by filtered cathode vacuum arc technology

Abstract

Ti3AlC2 MAX phases have attracted increasing attention due to their unique properties. However, high synthesis temperatures of Ti3AlC2 bulk materials limit their further development. In this work, Ti3AlC2 coatings were prepared by a two-step method with filtered cathode vacuum arc (FCVA) deposition at room temperature and annealing at 800 °C for 1 h. The structure and properties of coatings were investigated. The results showed that the formation of Ti3AlC2 phase in the annealed coating depended on the C2H2 flow rate during deposition. At low C2H2 flow rates (≤ 9 sccm), almost no Ti3AlC2 phase was formed. As the C2H2 flow rate increased, the annealed coatings mainly exhibited Ti3AlC2 phases, the texture of which transformed from (104) to (105) planes. Meantime, the hardness of Ti3AlC2 coatings continuously increased to a maximum of 20.7 GPa, and the corrosion resistance first increased and then decreased with the increase of C2H2 flow rate.