Effects of stress triaxiality on damage evolution from pre-existing hydrogen pores in aluminum alloy

It has recently been reported that aluminum alloy ductile fracture is dominated by micropore growth, whereas the particle fracture mechanism operates incidentally. The effects of stress triaxiality in front of a notch or crack were here investigated by employing microtomography observations. A fractional dimple pattern area originating in micropores increased with the increase in stress triaxiality on fracture surfaces. This implies that the effects of micropores on mechanical properties are more pronounced in notched and cracked materials.