Abstract: | Fracture surfaces of Epon 901/B-3 bonded aluminum alloy joints in the lap-shear configuration were studied using scanning electron microscopy. Major differences in the appearance of the fracture surface from those reported (8) for tensile loaded joints at 23°C are produced either by cyclic loading at 23°C or a change in test temperature to ?196°C. Fracture in tensile loaded joints at ?196°C is a brittle single step process in the opening mode in which rapid crack extension occurs throughout the joint with very little adhesive flow. Tensile fatigue fracture at 23°C is in the opening mode but crack extension is complicated by extensive adhesive flow throughout the entire joint. |