Laser surface alloying of Hastelloy X superalloy with Amdry 365 powder: Microstructural evolution and microhardness

Laser surface alloying is a surface modification technique that melts coat powder and substrate with high laser power density. This study aims to improve the properties of Hastelloy X, a Ni-based superalloy used for gas turbine components, by applying a NiCoCrAlY coating using laser surface alloying. The purpose of this study was to investigate the process parameters including laser scanning speed, laser power, and stand-off distance on the microstructure and microhardness of the alloying zones. The findings indicate that different microstructures were formed in different alloying zones such as cellular, columnar, and equiaxed. The results also revealed the presence of β and γ phases in the dendritic and interdendritic regions. The microhardness at the interface was higher than that of the other alloying areas due to the increased content of the Mo element. This study concluded that the properties of Hastelloy X can be improved by using NiCoCrAlY powder through a laser alloying process.