Strengthening effects of encapsulating graphene in SiC particle-reinforced Al-matrix composites

This work aims to reveal the strengthening effects of encapsulating graphene in the tensile strength of SiC particulate Al-based composites. Modified theoretical models are discussed regarding the thermal mismatch, Orowan and fine-grain strengthening mechanisms. It is found that the thermal mismatch strengthening is the dominant mechanism among them, followed by the Orowan strengthening and the fine-grain strengthening to be the last. While comparing the effects of two different types of graphene, we find that sheet graphene makes more strengthening contributions to both thermal mismatch and Orowan strengthening mechanisms compared with encapsulating graphene. Finite element simulations are employed to investigate the variation patterns of these effects with varies particle sizes and volume fractions. A better enhancing effect of encapsulating graphene can be achieved with a larger volume fraction and a smaller particle size.