Microstructure and wear resistance of the CuSn19Ti10/diamond composite coatings on copper substrate by laser cladding

Copper and its alloys are well-known for their excellent electrical and thermal conductivity but are limited by poor mechanical strength and wear resistance. In this study, CuSn19Ti10/diamond composite coatings with strong metallurgical bonding and free from defects such as cracks and porosity were successfully fabricated on pure copper substrates using laser cladding. The process parameters included a laser power of 3000 W, a scanning rate of 15 mm/s, a spot diameter of 2.5 mm, and a lapping rate of 30 %. A comprehensive analysis of the microstructure and wear resistance was performed on coatings with 0, 2.5 %, 5 %, and 10 % (wt%) diamond content using SEM, EDS, XRD, and white light interferometry. The results indicate that the coatings consist of alpha-(Cu), Cu2SnTi, (Cu, Sn)Ti2, TiC, and diamond phases. The addition of diamond significantly improved both the hardness and wear resistance, with the 5 wt% diamond composite demonstrating the most notable wear resistance. This optimal composition balances diamond content, ensuring effective retention within the CuSn19Ti10 matrix, thereby reducing plastic deformation and minimizing diamond pull-out during wear.