Microstructure and nanohardness of cold-sprayed coatings: Electron backscattered diffraction and nanoindentation studies

Electron backscattered diffraction and nanoindentation are used to identify how the local changes of microstructure influence the hardness distributions of cold-sprayed Ni and Cu coatings. The hardness in the vicinity of Ni particle interfaces can be about 1.5 GPa higher than that in the particle interior, and this difference is attributed to the cold-spray-induced grain boundaries and dislocation densities. The Cu coating with lower activation energy for recrystallization shows a more uniform microstructure and hardness distribution.