Acoustic Emission during Crack Formation in Fe-25Cr-5Al Alloy

The condition of crack formation in a Fe-25Cr-5Al alloy is investigated by acoustic emission and scanning electron microscopy techniques.The result shows that thermal stress induces to produce microcracks in the alloy.Because of the presence of internal stress and permeation of environmental hydrygen,the longitudinal cracks always occurred,and the failure of the alloy is a process of energy release showing by acoustic emission.