Effect of Thermal Fatigue Behaviour on Bending Strength of Al/Al_2O_3 MMCs

摘要

The thermal fatigue should be taken into account during the design of a composite structure, especially when thermal shock conditions occur. Hence the work was focused on the degradation of mechanical properties of alumina reinforced MMCs when they are exposed to thermal shock conditions which need to be investigated. Such events can occur frequently during the life-time of a composite; e.g. during manufacturing (cooling from melting temperature to room temperature) or during operation (external temperature of aircraft can change from -20℃ to 200℃ during landing, within few seconds). The residual properties studied were the elasticity modulus in bending and the respective maximum stress developed within the specimens. The specimens were subjected to number of thermal cycles using hot and cold chamber and bending strength was calculated. The fracture surfaces of the composite were observed by SEM.