Influence of Pre-Compression on Tensile Behaviour in Wrought MgZnCe Alloy Studied by the Acoustic Emission Technique

Wrought MgZnCe alloy (ZE10) has been pre-compressed and subsequently subjected to tensile loading. Due to a fibre texture of the samples, the level of pre-compression stress significantly influences the subsequent tensile behaviour. The acoustic emission technique was used for monitoring active deformation mechanisms dur-ing mechanical testing. The obtained acoustic emission results are correlated to the stress-time curves and the differences in the acoustic emission count rate were used to reveal changes in underlying deformation mechanisms. Firstly, a compression-tension cycle was monitored by the acoustic emission technique. Then, the samples were deformed to specific points on the stress-time curve, where acoustic emission exhibits strong changes in the activity. The following microstructure analysis of the samples, deformed to different strain-levels, by using electron back scattered diffraction method brought a detailed insight into active deformation mechanisms. Twinning during the pre-compression was followed by detwinning during the tensile loading. Two consecutive acoustic emission peaks, which appeared at larger strains, are explained by interplay of detwinning and dislocation slip and a nucleation of compression twins, respectively