Experimental and Numerical Study of Interfacial Fracture Parameters of a Brazed Joints

Abstract

This paper deals with an identification methodology of the interfacial fracture parameters to predict the lifetime of a metallic brazed joint. The methodology is based on an experimentalnumerical study whereby the optimal parameters are obtained. The experimental data, using the scanning electron microscope analysis, allowed approving that failure of the assembly based AuGe solder seems first to appear near the interfaces. These results were confirmed by micrographs analysis of the solder/insert and solder/substrate interfaces. Then, using shear test results and parametric identification coupled with a finite elements model (FEM) simulation, the damage constitutive law of the interfacial fracture based on a bilinear cohesive zone model are identified. The agreement between the numerical results and the experimental data shows the applicability of the cohesive zone model to fatigue crack growth analysis and life estimation of brazed joints.