Cold sprayed aluminum based glassy coating: Synthesis, wear and corrosion properties

Al-based glassy coatings were synthesized using cold spraying technique to protect 6061 aluminum surface from wear and corrosion. Gas atomized Al90.05Y4.4Ni4.3Co0.9Sc0.35 (at.%) powder was used as the starting powder. Dense (98%) coatings with a uniform thickness of ~ 250 μm were deposited. The coatings retained the glassy structure of the powder with few nanocrystals embedded in the amorphous matrix. Ball-on-disk wear of the coatings showed 600% improvement in the wear resistance as compared to 6061Al substrate. Potentiodynamic studies of the coatings in varying NaCl concentrations displayed 5 times better corrosion resistance than 6061 Al substrate, which was attributed to the active passivation and the chemical homogeneity of the coatings.