2012 Volume 53 Issue 9 Pages 1611-1616
Tension twinning readily occurs under compressive loading along extrusion direction because extruded AZ31 Mg plate has the texture with the basal planes parallel to the extrusion direction. Detwinning occurs in the twinned areas during tensile loading in the opposite direction. In this study, acoustic emission (AE) during the tensile test was investigated for the evaluation of detwinning behavior. Different AE features depending on the strain level were observed and detwinning behavior was divided into three stages. In the first stage, many AE signals with higher peak frequency were generated, then very few AE signals were observed in the second stage, and finally again some AE signals with lower peak frequency were observed in the third stage. In addition, EBSD analysis was conducted to identify phenomena in each stage. The results suggested that twin boundary starts to move in the first stage, then twin area shrinks in the second stage, and twin area disappears in the third stage. Deference of AE characteristics in each stage seems to be caused by these phenomena. It can be concluded that AE is an effective method for evaluation of detwinning behavior.