Corrosion resistance of Mg–8·8Li alloy compared with AZ91

Abstract

The superlight Mg–Li alloys exhibit good formability but poor corrosion resistance due to the alloying of lithium. In this paper, the corrosion behaviour of Mg–8·8Li alloy was investigated by electrochemical measurements, corrosion morphology observations and weight loss determination. The results indicate that Mg–8·8Li alloy displays worse corrosion resistance than AZ91D alloy in the early stages of corrosion. However, the corrosion resistance of AZ91D alloy declines and becomes worse than Mg–8·8Li alloy with increasing exposure time. In addition, it is found that a 250°C annealing treatment has a detrimental effect on the corrosion resistance of Mg–8·8Li alloy.