Evaluation of the deformation fields and bond integrity of Cu/SS joints

The stress states that lead to failure of joints between Glidcop(TM) CuAl25 and 316L SS were examined using finite element modeling techniques to expl ain experimental observations of behavior of those joints. The joints were formed by hot isostatic pressing (HIP) and bend bar specimens were fabricat ed with the joint inclined 45 degrees to the major axis of the specimen. Th e lower surface of the bend bar was notched in order to help induce a precr ack for subsequent loading in bending. The precrack was intended to localiz e a high stress concentration in close proximity to the interface so that i ts behavior could be examined without complicating factors from the bulk ma terials and the specimen configuration. Preparatory work to grow acceptable precracks caused the specimen to fail prematurely while the precrack was s till progressing into the specimen toward the interface. The finite element model demonstrated maximum stress concentrations in the interface layer to be shifted off-center. An additional benefit from the finite element model ing effort was in understanding if the stress states in this non-convention al specimen were representative of those that might be experienced in pract ice. (C) 2000 Elsevier Science B.V. All rights reserved.