Additive Manufacturing by Cold Spay Technology: Issues and Feasible Solutions

The additive manufacturing (AM) is an innovative method to produce functionalized components layer by layer. In the recent years, Cold spray process is contemplated as an AM processes especially for metallic materials due to the solid-state additives, low-temperature process, and high deposition efficiency of powder feedstock. Cold spray process offers substantial applications for structural or dimensional restoration, bulk production providing specific material properties and surface functionalization. Nowadays, numerous studies are focusing to increase the enactment of the cold spray process as a proven viable innovative AM process. However, there are several issues, especially associated with bulk manufacturing by the cold spray process. Present work focuses on such issues e.g. adhesive and cohesive failure on up-scaling, isotropic properties of the cold sprayed material, ductility in as-sprayed state and influence of thermal expansion behavior on coating/substrate system of two different materials. To resolve these issues, the relationships between parameters contributing bonding formations (e.g., particle size distribution of feedstock, plastic deformation, the temperature rise due to impact, and dynamic-recrystallization) and processing parameters (e.g., substrate preparation, pre-heating temperature, spray angles and impact velocity) were established. Microstructural and mechanical properties of as-sprayed and heat treated build-ups were investigated in three dimensions.