Abstract
The information obtained from fractured surface is quite relevant to failure analysis. In the present study, it was investigated whether the Exo-electron emission phenomena can be successfully applied to failure analysis. The Exo-electron (EE) emission from the fracture surface of a toughness test specimen was observed by using a scanning Exo-electron emission microscope. The difference in EE emission behavior between fatigue fracture and ductile fracture surfaces as well as the time decay of EE emission intensity were investigated.
A significant difference in EE emission intensity was observed between fatigue fracture and ductile fracture surfaces. A good correlation was found between the J-integral range at fatigue cracking and the EE emission intensity of the fatigue fracture surface. The characteristics of decay of EE emission intensity was given as
I(t)=I0exp(k1t)[A+Bexp(-k2t)]
where I0 is the intensity of EE emission at t=0, k1, k2, A and B are constants. There is a good correlation between ΔJ and k1. ΔJ can be estimated by determining the k1 value from the decay curve.
