Deposition and microstructures of cold sprayed Cu-Cu2O coatings

The Cu-Cu2O coatings, with Cu2O mass contents of 0.0%, 10%, 20% and 30%, were deposited by cold spraying on Q235 steel substrates. The impacts of the spraying conditions, including the spraying temperature, injection pressure, nozzle-substrate separation, deposition rate, and contents of Cu and Cu2O, on the porosity and mechanical properties of the Cu-Cu2O coating were evaluated. The Cu-Cu2O coatings were characterized with X-ray diffraction, environmental scanning electron microscopy, metallographic microscope, and conventional mechanical probes. The results show that the coatings effectively improve the micro-hardness and sea-water corrosion resistance. For example, all the coatings, with compact surface, low porosity, and fairly strong interfacial adhesion, are capable of effectively blocking sea-water permeation and surface corrosion. Moreover, an increase of Cu2O content resulted in the increased average deformation rate of Cu particles, and micro-hardness of the coating.