Investigation of the dissolution-precipitation behavior and properties of high-speed laser cladding WC/316L composite coatings

Abstract

High-speed Laser Cladding (HLC) technology was used to fabricate WC/316L composite coatings with varying WC contents on a 316 L alloy substrate. The microstructure of the coatings, along with the dissolution and precipitation behavior of WC and the wear mechanism, were investigated. The results show that during the cladding process, the edges of WC dissolve to form a W-rich zone. Upon cooling, W atoms nucleate and precipitate carbides at the WC/316L interface, resulting in strong interfacial bonding between WC and the 316 L substrate. The phases in the coating include austenite, WC, M2C, M7C3, and M3C2. As the WC content increases, the austenite content decreases. WC enhances the wear resistance of the coating by increasing hardness, dispersing the load on the matrix, and passivating wear debris. The wear rate of the 316 L + 30WC coating is only 27% of that of the 316 L alloy.