Cold spray deposition of heat-treated Inconel 718 powders

In this work, Inconel 718 gas-atormzed powder was successfully heat treated over the range of 700-900°C. As-atomrzed and as-heat treated powders were cold sprayed wrth both mtrogen and helium gasses. Cold spray of high strength materials fs still challenging due to their resistance to particle deformation affecting the resulting deposit properties. Powder heat treatment to modify its deformation behavior has recently been developed for aluminum alloy powders, however; there is no literature reported for Inconel 718 powders. The microstructural evolution of the powder induced by the heat treatment was studied and correlated with their deformation behavior during the cold spray deposition. Deposits sprayed with heat-treated powders at 800 and 900 °C and nitrogen showed less particle deformation and higher porosity as compare to as-atomized deposit associated to the presence of delta[phase inlhe powders precipitated by the heat treatment. In contrast, deposits sprayed with helium using both powder conditions, as-atomized and as heat-treated powders, showed high particle deformation and low porosity indicating that the type of gas has a greater effect on the particle deformation than the delta phase precipitated in the heat-treated powders. These results contribute to understanding the role of powder microstructure evolution induced by heat treatment on the cold spray deposits properties.