Effect of Sc and Zr additions on microstructure, hardness, and corrosion resistance of Al-Ni-Mn alloys

Al-Ni binary alloys are interesting to use at high-temperature applications due to thermal stability of phases. The addition of Mn, Sc, and Zr in Al-4Ni aluminum alloy enhances the mechanical properties through the simultaneous effect of transformation of Al3Ni to Al9(Ni, Mn)2 eutectic and Al3(Sc, Zr) precipitates. The hardness in as-cast and aging at room and high temperature are studied. Electrochemical testing was performed in as cast and aged alloys and the value of current density (Icorr) and potential corrosion (Ecorr) were determined to discuss the corrosion behavior. The microstructure changes were observed after the electrochemical corrosion testing. The transformation of fiber eutectic and precipitates are expected to improve the corrosion resistance of the alloys.