Comparison of Corrosion Resistance of High Pressure Die-Cast and Semi-Solid Cast AZ91, AM60, Alloys and Respective Anodic Oxides

Abstract

A comparison of corrosion resistance of die-cast and semi-solid cast AZ91and AM60 magnesium alloys was performed in corrosive medium by measurement of the open circuit potential and potentiodynamic scans. Before testing, a heat treatment was carried out on the semi-solid cast alloys. Moreover, electrochemical measurements were performed on the four different substrates anodized in the micro-arc regime in an environment friendly alkaline aqueous solution. The results could be correlated to the different microstructures of the samples produced by the different processes and to the different compactness/porosity of the oxides.