Direct observation of the twinning mechanism in an austenitic Fe-Mn-C steel

The mechanism operating during mechanical twinning has been studied in a low stacking fault energy austenitic steel. The validity of Schmid's law for twinning is directly verified using transmission electron microscopy. Based on this, the critical resolved shear stress could be determined, both for slip of twinning dislocations and undissociated dislocations. The observations made are in agreement with the twinning model proposed by Mahajan and Chin. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.