Improvement of Corrosion Resistance of Rolled and Heattreated AA6111 Alloys with Zirconium addition
Improvement of Corrosion Resistance of Rolled and Heattreated AA6111 Alloys with Zirconium addition
Keywords:
AA6111 aluminum alloy; Al-Mg-Si-Zr alloys; corrosion behavior; particle size; Potentiodynamic polarization.Abstract
The zirconium addition effect on the corrosion behavior of the AA6111 alloy was investigated.
All alloys were produced by the stir-casting method. Homogenization heat treatment (at 500
ºC for 8 hours) was performed on the AA6111 alloy only. The alloys were solutionized (at 540
ºC for 30 minutes) and artificially aged (at 180 ºC for 10 hours). Particle size measurements,
XRD, energy-dispersive X-ray spectroscopy (EDS), open circuit potential (OCP)-time
measurement, and potentiodynamic polarization were performed for all samples. The
microstructure analysis displayed different fine intermetallic phases distributed in large
amounts in the AA6111+0.54%Wt%Zr alloy compared to the AA6111 alloy. From the results
of electrochemical tests, it is clear that the addition of zirconium to the AA6111 alloy has led
to a significant and noticeable improvement in corrosion resistance, as the improvement rate
reached 72.53%. Compared to the AA6111 alloy without adding zirconium.
