Effect of carrier gases on microstructural and electrochemical behavior of cold-sprayed 1100 aluminum coating

Aluminum has been cold sprayed onto similar substrate using 100 vol.% He and mixture of He-20 vol.% N2 as carrier gases. Analysis and characterization of sprayed depositions under different processing conditions was performed through optical micrography, stereological analysis, scanning electron microscopy, and microhardness depth profiles. Potentiodynamic polarization curves and Tafel extrapolation experiments were carried at 0.9 pH value using sulfuric acid (H2SO4) as an electrolyte. Helium processing condition displayed more compact structure and higher hardness for the coating when compared to He-20 vol.% N2 processing. Electrochemical studies depicted better corrosion resistance of the He-20 vol.% N2-processed coatings when compared to coatings processed with helium alone. D 2004 Elsevier B.V. All rights reserved.