Microstructure, high-temperature oxidation and tribological performance of cold-sprayed CuCrZr coating

Abstract

An CuCrZr powder with appropriate component contents and particle size distributions were prepared by using gas atomization. The microstructural evolution, mechanical properties, high-temperature oxidation, and wear behaviors of cold-sprayed CuCrZr coatings were investigated. Results shows that the flowability and bulk density of the prepared powder are 18.04 s/50 g and 10.29 g/cm3, respectively. Due to the deformation-induced work-hardening, the coating exhibits a hardness of 5.46 GPa and an elastic modulus of 208.49 GPa, which is 59.6 % and 80.9 % higher than the substrate, respectively. At temperatures of 400–600 °C, the oxidation products of both coating and substrate are composed of Cu2O and CuO, while the coating's Cu2O is denser and offers better oxidation resistance. And the wear resistance of CuCrZr coating (4.24 × 10−15 m3·(N·m)−1) at 400 °C is much better than that the CuCrZr substrate (7.89 × 10−15 m3·(N·m)−1). The friction and wear properties of both coating and substrate significantly decrease with temperatures. The wear mechanism of CuCrZr coating at high temperatures is a combination of oxidation wear and abrasive wear. The cold-sprayed CuCrZr coating, exhibiting excellent oxidation and wear resistance, shows a high potential for repairing copper alloy parts.