The corrosion characteristic of Mg-3Nd alloy without and with Al addition

Abstract

The microstructure and corrosion behaviors of Mg-3Nd alloy without and with Al addition were characterized in the present work. The experimental results show that the microstructure of Mg-3Nd alloy is significantly refined by Al addition. There are two kinds of precipitated phases in the alloy with Al addition, which are Al11Nd3 phase and Al2Nd phase. With increasing the Al addition, the Ecorr increases and the Icorr decreases in Mg-3Nd alloy. The average immersion corrosion rate of Mg-3Nd alloy without Al addition is lower than that of Mg-3Nd alloy with 1% and 2% Al, but higher than that of Mg-3Nd alloy with 3% Al. When the Al content was 3%, the corrosion potential is −1.482 V, corrosion current density is 6.93 μA/cm2 and the corrosion rate is 0.69 mg cm−2·day−1. The Mg-3Nd alloy without Al addition have a high frequency and a low frequency capacitive loop. The Mg-3Nd alloy with 1% and 2% Al has only a high frequency capacitive loop. When the Al addition is 3%, there are one high frequency capacitive loop and one low frequency inductive loop. The corrosion mechanism is different for Mg-3Nd alloy with increasing the Al addition.