The effect of temperature and residual stress on deformation and fracture of SiC/Ti-24Al-11Nb

This paper reports on the effects of temperature and residual stress on the tensile stress-strain curves of 0 degrees SiC/Ti-24Al-11Nb composites that are examined and failure mechanisms were characterized. An elastic-plastic, concentric cylinder model was used to predict residual stresses. Predicted and experimental residual stresses agreed stresses. Predicted and experimental residual stresses agreed well. Consideration of residual stress was necessary to predict the composite elastic limit. Fiber fracture appeared to control composite failure at all temperatures. Intermittent fiber fractures occurred throughout the specimens at 23-425 degrees C. However, at 650 and 815 degrees C, fiber fractures were present only close to the composite fracture surfaces, near the region of matrix necking. Unusual stress-strain behavior was observed at 650 and 815 degrees C and may be related to the extremely low shear stresses measured at these temperatures