Abstract Inconel 718 is a precipitation-hardenable nickel-base superalloy with decent corrosion resistance, high strength at ambient temperature, and excellent creep and fatigue strength at high temperature. In this study, Inconel 718 was deposited by cold spraying with nitrogen and helium gas. Particle velocities were measured and splat morphology and coating microstructure were observed. Mechanical properties, including hardness, bond strength, and tensile strength, were also investigated. Although the deposits sprayed with helium had slightly better mechanical properties, nitrogen-sprayed Inconel 718, post heat treatment, exhibited mechanical properties similar to those of the bulk material.
Abstract Cold spray 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 processes, dense coatings without any degradation can be obtained by cold spray process with high deposition efficiency. CoNiCrAlY coatings are widely used for land-based gas turbines to resist high-temperature oxidation and hot corrosion. Owing to the high cost of the low-pressure plasma spray (LPPS) or some degradation in the hyper-velocity oxy-fuel (HVOF) spray process, cold spray process is a prospective candidate for coating preparation. In the current study, CoNiCrAlY coatings were prepared by cold spray and LPPS processes, 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.
