Microstructure formation and evolution mechanism of Cu-Ti coating during dual-magnetron sputtering and thermo plasma nitriding

Dual magnetron sputtering and thermo plasma nitriding were performed to fabricate Cu-Ti-N coating on the surface of Cu substrate, and the microstructure formation and evolution mechanism were investigated. The results showed that the composition of the Cu-Ti coating could be tuned to be around Cu:Ti = 1:1.2 by the appropriate choice of sputtering power for the dual targets, and only amorphous Cu-Ti phases formed. During the thermo plasma nitriding process, crystalline CuTi and Cu3Ti occurred. Moreover, a nitride layer of about 0.3 μm containing nanocrystalline TiN formed on the surface, and the multi-phase coating developed to be about 4 μm, which could provide better support for the nitrided layer.