Property Enhancement of Cold Sprayed Al-Diamond MMC Coating by Using Core-Shelled Diamond Reinforcements

Super wear-resistant aluminum-based metal matrix composite (MMC) coatings were produced using cold spraying. Cu-Ni coated diamond and pure diamond particles were used as reinforcing agents. Test results show that the metallic Cu-Ni shell served as a buffer layer, preventing the fracture of diamond particles upon impact as occurred with the uncoated diamond. The coated diamond particles were also found to have a higher deposition efficiency due to metallurgical bonding between the Cu shell and Al matrix. Under tribological testing, all coatings performed well, but those reinforced with the coated diamond showed higher wear resistance due to higher diamond content and involvement of Cu and Ni.