In situ damage assessment in a cast magnesium alloy during very high cycle fatigue

Damage evolution during very high cycle fatigue (VHCF) in AXJ530 die-cast magnesium alloy was studied in situ using nonlinear ultrasonic measurements via analysis of the feedback signal of a closed-loop ultrasonic fatigue system Variations in acoustic nonlinearity with fatigue cycles revealed cyclic hardening/softening during early fatigue life (<10(8) cycles) as well as the initiation and growth of a dominant fatigue crack in the VHCF regime (N(f)=0 82 x 10(9) cycles) (C) 2010 Acta Materialia Inc Published by Elsevier Ltd All rights reserved