Influence of laser surface hardening on corrosion properties of Al-Zn-Si cast alloy

Abstract

This work is focused on the effect of the laser surface treatment (laser power 50 and 80 W) on microstructure and corrosion properties of self-hardened AlZn10Si8Mg cast alloy used for engine and vehicle constructions. The electrochemical impedance spectroscopy (EIS) technique and Nyquist plots in a 1M NaCl test solution at 20 °C were carried out. A detailed corrosion study showed that corrosion resistance samples with laser layer were marginally less; probably the presence of chloride ions significantly damaged the Al2O3 film and caused the formation of NaAlO2.

Keywords

• Al-Zn-Si cast alloys
• laser surface hardening
• microstructure
• corrosion properties