Comparison of corrosion behaviour of friction stir processed and laser melted AA 2219 aluminium alloy

Dissolution of second phase particles (CuAl2) present in AA 2219 aluminium improves the corrosion resistance of the alloy. Two surface treatment techniques, viz., solid state friction stir processing and fusion based laser melting lead to the reduction in CuAl2 content and the effect of these processes on the corrosion behaviour of the alloy is compared in this study. Potentiodynamic polarization and electrochemical impedance spectroscopy tests were carried out to compare corrosion behaviour. The corrosion resistance achieved by friction stir processing is comparable to that obtained by the laser melting technique.

► Poor corrosion resistance of AA 2219 can be improved by surface treatments. ► FSP and LM leads to dissolution of second phase particles. ► No literature available on comparison of corrosion behaviour after FSP and LM. ► The study implies FSP is as good as LM in improving the corrosion resistance of AA 2219.