High temperature wear performance of in-situ forming textured Ni60/WC/h-BN composite coatings based on laser micro-cladding

Abstract

In this study, electrohydrodynamic atomization technology and laser micro-cladding technology were used to design and prepare circular, square and bionic Nepenthe-shaped micro textures on the cemented carbide substrate. The mechanical properties of the prepared micro texture are significantly improved. The effects of different micro texture morphology on the tribological properties of the substrate in a wide temperature range were systematically studied. The results investigated that the bionic Nepenthe-shaped micro-texture showed the lowest friction coefficient at all temperatures, and when the temperature was 200 °C, the friction coefficient could be reduced to ∼0.14. The wear track analysis shows that the micro texture is the main way to reduce the friction coefficient at room temperature. When the temperature rises to 200 °C, the h-BN in the cladding layer will release at the friction interface to achieve the lubrication effect. When the temperature further increases, the cladding layer will soften and be smoothed, and the substrate will directly contact with counter ball, which will significantly increase the friction coefficient. By exploring the effect of micro texture morphology prepared by laser micro cladding technology on tribological properties, we can understand its applicability in different manufacturing tools.