Enhancing corrosion resistance of Mg-Nd-Zr-In alloys via the development of a triple-layered In (Indium) rich corrosion product film

Abstract

The influence of minor concentrations of indium (In) on the microstructure, corrosion behavior, and mechanical properties of Mg-2.5Nd-0.5Zr-xIn alloys were studied. The mechanisms of corrosion protection were examined. Herein, Mg-2.5Nd-0.5Zr-1.0In exhibited the lowest corrosion rate (0.122 mm/y). The addition of an appropriate amount of indium not only reduced the grain size of Mg-2.5Nd-0.5Zr-xIn alloys but also decreased the size of the Mg12(Nd,In) and Mg41(Nd,In)5 phases, promoting uniform corrosion. The excellent anti-corrosion behavior of the Mg-2.5Nd-0.5Zr-1.0In alloys was ascribed to the growth of a unique three-layer corrosion product film, facilitated by the enriched In element near the Mg matrix.