Effect of Micro-Alloying Elements on Deformation Behavior in Mg-Y Binary Alloys

Abstract

The effect of minor yttrium atom addition on deformation behavior was investigated using Mg X atY (X＝0.01, 0.02, 0.03, 0.04 and 0.05) dilute alloys and pure magnesium with an average grain size of about 50 mm. The stress and strain curves in all the alloys showed a sigmoidal shape in the compression tests, which suggested the formation of {10˜12} type twinning due to the lack of slip system. On the other hand, yttrium atom addition of more than 0.03 at was effective to affect the deformation behavior: a large compressive strain of 0.5 was possible to obtain, and the sub grained and fine grained structures were formed even at room temperature in three kinds of alloys. The dominant deformation mechanism in these alloys was the twinning at the beginning of the state and the dislocation slip with further imposed strain.