A study on the mechanical and thermal shock properties of MCrAlY coating prepared by arc ion plating

In this study, MCrAlY coatings with different microstructures were prepared by arc ion plating to investigate the mechanical and thermal shock properties of the coatings. The results show that arc ion plating MCrAlY coatings overall possessed similar hardness (7.66 GPa-9.20 GPa) but lower elastic modulus (119.07 GPa-148.02 GPa), compared to those prepared by conventional thermal sprayings. The microstructure of the coating had a significant impact on the thermal shock property. The coating with a columnar structure exhibited a poor thermal shock property. After the thermal shock test, the coating failed in the form of penetrating cracks, which ultimately caused stress corrosion in the substrate. A dense and laminar structure was a desirable structure for ideal thermal shock property, which could be achieved by increasing the bias voltage applied to the substrate during the preparation process of the coating. However, in that case, the oxidation resistance of the coating was decreased due to the loss of Al in the coating.