Modeling of thermal expansion behavior of densely packed Al/SiC composites

In this paper the approach for finite element (FE) modeling and analysis of thermal expansion behavior of densely packed Al/SiC composites is proposed. The coefficient of linear thermal expansion (CTE) is predicted from 50 °C to 500 °C by considering temperature dependent linear elastic and elastoplastic matrix material behavior. Three dimensional representative volume elements (RVEs) are generated to model the composite's microstructures. In order to study the effect of thermal residual stresses, first the RVEs are simulated for cooling process from processing temperature to room temperature and thermal residual stresses are estimated by considering different mechanical behaviors of Al matrix. Next, the thermal expansion behavior is examined with existing residual stresses. The presence of thermal residual stresses is observed to influence the effective CTE in the initial temperature range (25 °C-100 °C) of heating. The contact state of reinforced particles significantly influences the thermal expansion behavior. It is observed that the effective CTE of composites with non-interpenetrating microstructure is higher than that of the composites having interpenetrating microstructure. The effects of voids on the thermal expansion behavior are analyzed further.