Comparison of the Characteristics of CoNiCrAlY Coatings Prepared by Cold Spray and LPPS Process

Cold spraying is a new emerging coating technology in which particles in a solid state are deposited via plastic impact on a substrate at a high velocity and a temperature that is much lower than the melting point of the starting powder. Compared to the conventional thermal spray process, the dense coatings without any degeneration can be obtained by cold spray process with high deposition efficiency. CoNiCrAlY coatings are widely used for land-based gas turbine to resist high-temperature oxidation and hot corrosion. Owing to the high cost for low-pressure plasma spray (LPPS) or some degeneration for HVOF process, cold spray process is a prospective candidate for the preparation of the coatings.

In the current study, CoNiCrAlY coatings were prepared by cold spray and LPPS process, and a comparison of the coating’s properties between the LPPS and cold spray process was carried out. The spray conditions of cold spray were optimized by the measurements of deposition efficiency and the observations of microstructure.