An Investigation of Al-SiCp Composites Under Thermal Cycling

The effect of thermal cycling on the behavior of the aluminum-silicon matrix alloy Al-7%Si-0.7%Mg (AlSi7) reinforced with 10% volume SiC particles has been investigated experimentally and theoretically. Cast ingots of the matrix alloy and composite samples were extruded at 773 K at an extrusion ratio of 10:1. The extruded microstructures exhibit a more uniform distribution of the SiC particles. In this study, for determining the thermal stress and deformation on the composite materials ABAQUS finite element software package was used. Thermal residual stresses developed during and after thermal cycling were also investigated. Thermal cycling tests were performed between 373 and 703 K under a constant tensile load (150 N) and without external load. The stress distributions in the composite during heating and cooling were revealed. The axial displacement under constant external load after one thermal cycling was 0.01672 mm and kept increasing considerably. The maximum residual stresses were generated at the interfacial region during thermal cycling. SEM micrographs showed that cracks were present in the composite structure under repeated action of thermal cycling process (100 cycles).