Abstract
Cold spraying is a novel coating method in which coating is formed by mechanical deformation of sprayed metal particles. This heavy deformation causes structures, which need recrystallization heat-treatment in order to gain back the materials natural deformability. Aluminum, copper, nickel and Ni-20%Cr were cold sprayed and heat-treated at several temperatures. Coatings were sprayed using nitrogen as process gas. Substrate material was carbon steel. Heat-treatment temperatures were chosen from near room temperature to below coating materials melting temperature. As-sprayed and heat-treated coatings were characterized in microstructure, hardness, phase structure and electrical resistivity. It was found that 200ºC was enough to increase electric conductivity to 87% of pure copper. By heat treatment ductility was able to be increased and hardness subsequently decreased.
