Effect of Heat Treatment on Residual Stress of Cold Sprayed Nickel-based Superalloys

Residual stress formation during cold spraying process may result in deteriorative effects on the performance of coating materials. The objective this investigation is to characterize residual built-up two well-known nickel-based superalloys (Inconel 625 and Inconel 718) deposited using technique. To end, was precisely measured x-ray diffraction method. Here, subsurface regions only studied because surface properties alter sample preparation. average slightly higher compared 718 sample. Heat treatment at 800 °C helped reduction porosities which exerted tensile both coatings. Stresses with opposite signs could cancel each other after heat treatment. However, recovery for coating. In next step as-sprayed heat-treated samples were subjected microindentation test measure their hardness study crack samples. exhibited than 718, but decreased more drastically While cracks formed around indents, no found results from will contribute better understanding spray under service conditions effect relaxation elimination stress.