Ductile Fracture in Constrained Thin Metal Films

约束金属的韧性断裂机制将采用力学-材料科学的综合方法进行研究。涉及约束金属的常见工程情况是薄夹层，如焊接和钎焊，集成电路和某些复合材料中的金属互连。目前的韧性断裂理论通常是基于空洞的生长，这反过来又需要不切实际的大塑性应变。两种新的空腔膨胀模型不需要宏观塑性或基于空腔核聚结的机制似乎更合理。高三轴应力状态将研究使用银层间试样，没有体积缺陷。在小塑性应变下，通过扫描电子显微镜和高压透射电子显微镜观察了层间空洞微观结构的变化。＊＊＊

9522206 Kassner The ductile fracture Mechanisms of constrained metals will be studied using an integrated mechanics-materials science approach. Common engineering situations involving constrained metals are thin interlayers such as welds and brazes, metal interconnects in integrated circuits and some composites. Current theories for ductile fracture are generally based on cavity growth which in turn require unrealistically large plastic strains. two new cavity expansion models that do not require macroplasticity or cavity nuclei coalescence based mechanisms appear to be more reasonable. High triaxial stress states will be studies using silver interlayer specimens that are free of bulk defects. Changes in the void microstructure of the interlayer will be examined at small plastic strains via the scanning electron microscope and high voltage transmission electron microscopy. ***