Abstract
Electroplated nickel can be used to fabricate miniature components such as gears, linkages, and other two-dimensional mechanical structures. This process produces excellent parts, but it is slow and somewhat expensive. Because cold spray produces low oxide-content, high-density deposits at a high rate, cold spray processing might be a viable alternative to electroplated nickel components. In addition, cold gas-dynamic spray can process materials, such as stainless steel and aluminum, which can not be electroplated. The purpose of this study was to evaluate the mechanical properties of cold spray nickel in the as-sprayed and heat treated conditions, then compare them to those of bulk nickel and electroplated nickel. Characterization of freestanding structures is subjective since the final product of any thermal spray process produces a material unlike any other material formed by conventional techniques. Specifically, this investigation determines the mechanical characteristics of nickel, through metallographic imaging and tension testing. Metallographic imaging showed that as-sprayed nickel has slightly more voids than the heat-treated structures. Tension tests of the as-sprayed nickel showed little plastic behavior, while a heat treatment gives much more ductility without compromising ultimate strength.
