The corrosion behavior of cold spray coating on 2219 aluminium alloy joints prepared by friction stir welding

Abstract

A compact coating was deposited on the surface of a friction stir welded 2219-T6 aluminum alloy joint via cold spraying for corrosion protection. The results showed that a relatively dense coating could be formed in the FSW joint surface. Corrosion resistance of the coating is pretty good with the average discharge potential of -0.638 V (vs. SCE) and corrosion current density is 7.034 μA•cm-2. Immersion tests in the exfoliation solution confirmed that the presence of coating significantly decreased the corrosion attack. The corrosion of coating begins with pitting, which is mainly at the coating porosity. It gradually developed into the intergranular corrosion and exfoliation corrosion ultimately.