The directed energy deposition additive manufacturing was applied to fabricate hard Co-Cr-W layers on the 316L stainless steel substrate. The effect of different heat treatment cycles was investigated. The primary microstructure of deposited layers contained a cobalt matrix with interdendritic eutectic carbides mainly M7C3, M23C6, and M6C. Most of the primary carbides were dissolved in the matrix after the solution treatment at 1250 ◦C for 1 h. The aging treatment promoted the precipitation of (W/Co)6C carbides. The hard carbides caused the thirdbody wear and increased the wear volume loss of specimens. The solution & double aging treatment provided the optimum combination of hardness and wear resistance due to the best distribution of W/Co carbide. The wear volume loss after heat treatment was decreased from about 6.6 mm3 to 2.8 mm3 compared to the sdeposited specimen. The proposed solution & double aging heat treatment improved wear resistance by 50%.

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