Laser cladding of heterogeneous structured Cu-Cr-W-SiC coatings with balanced electrical conductivity and wear resistance

Although copper alloys exhibit high electrical conductivity, their inherent low hardness and insufficient wear resistance significantly limit their application in high-energy current-carrying friction scenarios. This study leverages the liquid–liquid phase separation (LLPS) characteristics of immiscible alloys during non-equilibrium solidification and employs laser cladding technology to fabricate Cu-36Cr-xW-4SiC (x = 0, 2, 5, 10 wt%) composite coatings on CuCrZr alloy. The research systematically investigated the influence of tungsten content on the heterogeneous microstructure and the regulation of electrical conductivity-wear properties of the coatings. The results indicate that the introduction of 2 wt% W suppresses the Stokes migration effect of the second phase in the molten pool, promoting the periodic layered distribution of Cr-rich hard phase regions along the edges of the molten pool. This forms a hardness gradient up to 12 times higher than the Cu-rich soft phase regions. This heterogeneous structure achieves decoupled optimization of conductivity (35.8 % IACS) and wear resistance (average volumetric wear rate of 0.158 mm³/km, an 88.5 % reduction compared to the substrate) through a synergistic mechanism of “hard phase bearing wear load − soft phase maintaining conductive pathways”. The design strategy proposed in this study provides a new paradigm for the development of high-performance copper-based coatings.