Improvement in the mechanical properties of plasma spray ceramic-Cu/TI3AlC2 gradient coatings by heat treatment

摘要

Interface durability of thermal spraying ceramics and metal bond-coats is crucial for their service life. However, most of the studies have focused on improving the interfacial durability of a single metal/alloy bond-coat. In this study, a ceramic-Cu/Ti3AlC2 composite coating was successfully prepared by atmospheric plasma spraying, and its microstructural evolution during the heat treatment and the changes in its mechanical properties from the substrate to the top-coats were investigated systematically. The heat-treated bond-coats showed a gradient interpenetrating structure with a large number of nanoparticles and reticulated Cu. In bond-coats, the ceramic layer connected to the top-coats, and the Cu mesh connected to the substrate. Through gradient interpenetrating structure of bond-coats, the substrate and top-coats was nailed together. Hardness and Young's modulus gradients of the interpenetrating-structured coating were observed from the top-coat to the substrates. This improved the interface durability between the top-coats and the bond-coats. A feasible bond-coat preparation method was proposed to improve the interfacial durability of ceramic coatings.