A Study on the Microstructure and Properties of CoCr Alloy Deposited Via Arc Deposition on a Single-Crystal Alloy

Three types of CoCr alloy welding wires were deposited on the surface of a single-crystal alloy using gas tungsten arc-welding (GTAW) technology to enhance its wear resistance. Comparative studies were conducted on the microstructure, microhardness, friction and wear properties, and tensile properties of the deposited alloy layers. The results showed that the deposited CoCr alloy layers formed good metallurgical bonding with the substrate, and the microstructure mainly consisted of planar crystals, coarse columnar dendrites, and fine, dense equiaxed dendrites. The microhardness of joints formed by depositing CoCr alloy welding wires increased with increasing distance from the interface, exhibiting a distribution pattern where the center of the deposition layer had the highest hardness, followed by the interface, while the base material had the lowest hardness. The highest hardness of the deposited layers of the S1 alloy was 119.5 HRC, with significant fluctuations in the deposition layer area. The wear resistance was significantly improved after depositing, and decreased significantly with increasing service temperature. The tensile strengths of the three welding wires were similar. The joint strength gradually decreased as the test temperature increased, with the S12 alloy joint exhibiting superior performance at high temperatures.