The slip activity during the transition from elastic to plastic tensile deformation of the Mg-Al-Mn sheet

Abstract

The deformation behavior of the Mg-Al-Mn sheet was investigated during tensile loading along the rolling (RD) and transversal direction (TD) with special attention to the early stage of deformation. The activity of dislocation slip systems during the transition from elastic to plastic deformation was revealed by the acoustic emission (AE) technique. The parametrization and statistical AE analysis using the adaptive sequential k-mean (ASK) clustering provided necessary information about the individual deformation mechanisms and their evolution. The AE findings were supported by microstructural analyses, including in-situ secondary electron (SE) imaging and Schmid factor estimation for the activity of particular dislocation slip systems with respect to the loading direction. It was found that basal slip is the dominating mechanism up to the stress of ∼ 80 MPa in both loading directions with an absolute dominance during the RD-loading, while during the TD-loading, the contribution of prismatic slip to the deformation at stresses above 50 MPa was determined. Below the yielding in both loading directions, the predominance of prismatic over pyramidal slip was found at the stress in the range of 80–110 MPa and the opposite tendency occurred at stresses between 110 and 140 MPa.

Keywords

• Magnesium sheet
• Yield asymmetry
• Acoustic emission
• Clustering