Cold gas dynamic spraying of a novel micro-alloyed copper: Microstructure, mechanical properties

Pure copper is known to present very high thermal and electrical conductivities, but poor mechanical properties. In this study, a novel micro-alloyed copper was prepared in a powder form by inert gas-atomization with a mean particle size of about 30 μm. Solid parts with high tensile strength (over 500 MPa) were manufactured by cold spray with helium as processing gas. Tensile, microhardness tests and instrumented indentation were employed to determine their mechanical properties. As expected the as-sprayed cold sprayed micro-alloyed copper deposit exhibits a higher ultimate tensile strength (UTS) than as-sprayed pure copper, both prepared at same spraying condition. The post heat treatments indicate that micro-alloyed copper presents higher recrystallization temperature than that of pure copper. Additionally, the ductility of cold sprayed deposits could be significantly improved by following heat treatment.