STUDIES ON TENSILE PROPERTIES AT VARIOUS STRAIN RATES AND CORROSION BEHAVIOR OF PEAK-AGED Al-6Si-0.5Mg (-0.5Cu) ALLOYS

This paper focuses on the effect of Cu additions on the tensile properties of the Al-6Si-0.5Mg alloy at various strain rates and electrochemical corrosion behavior. The addition of Cu resulted in an increase in the tensile strength and showed higher strength all over the experimental strain rates. Evaluations of tensile properties at the three different strain rates (10^-4, 10^-3 and 10^- 2 s^-1) showed that they affected the tensile properties significantly. The strength was better at higher strain rate but ductility was poor. Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarisation have been used to evaluate the corrosion resistance of Cu-free and 0.5 wt% Cu content Al-6Si-0.5Mg alloy in a 0.1 M NaCl solution. The 0.5 wt% Cu addition to the Al-6Si-0.5Mg alloy showed that Cu decreased susceptibility to corrosion compared to the Cu free Al-6Si-0.5Mg alloy. The magnitude of the open circuit potential (OCP), corrosion potential (Ecorr) and pitting corrosion potential (Epit) of the Al-6Si-0.5Mg alloy were shifted to the more noble direction due to the 0.5 wt% Cu addition and thermal modification.