Predicting Micro-Mechanics Damage Behaviour at a Metal-Ceramic Interface in a Reinforced Alloy

Abstract

The performance of metal matrix composites (MMCs) depends critically on the quality of the matrix-reinforcement interface. The nature of the interface in turn depends on the processing of the MMCs. At the micro-level, local concentration gradients around the reinforcement are being developed during processing and due to the metal matrix attempting to deform during deformation which can be very different to the nominal conditions. This plays a crucial role in the development of micro-structural events such as segregation and precipitation at the matrix-reinforcement interface. Micro-deformation characteristics of matrix reinforcement interface are modelled using commercial FE software and compared with analytical and experimental data. A method of calculation has been applied to predict the interfacial fracture strength of aluminium silicon carbide (Al-SiC) with 20% Vol fraction. Preliminary results show that the model succeeds in predicting the trends in relation to segregation and intergranular fracture strength behaviour in these materials. The proposed hypothesis will help the design engineers to select and use the materials in structural/load bearing applications. Interfacial strengthening characteristics will in turn give more accurate life predictions of such smart composite systems.