Relationship between fatigue crack initiation and activated {1 0 (1)over-bar 2} twins in as-extruded pure magnesium

An investigation of the fatigue behaviour of as-extruded pure Mg demonstrates that the fatigue strength corresponding to 10(6) cycles is 35 MPa. An analysis of the microstructural evolution during the fatigue process reveals that the activated twins are mainly {1 0 (1) over bar 2} type and their density increases with the number of fatigue cycles. The twin boundary (TB) cracking due to the interactions between TBs and slip bands is the key reason for the crack initiation of fatigue samples. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.