Sliding-induced Microstructure of Cold-Sprayed Copper Coating Observed by Electron Channeling Contrast Imaging

Cold gas dynamic spray is a coating process for fabrication of materials that are sensitive to heat and oxidation such as copper [1]. In cold spray, the particles are accelerated to supersonic velocities typically between 500 1200 m/s [1]. Upon high speed impact, the cold sprayed particles undergo extensive plastic deformation at very high strain-rates (up to 10 9 s -1 near impact interfaces), under which conditions complex microstructures are generated such as high density dislocation walls, deformation twins, elongated and equi-axed grains and sub-grains [2-3].