Microstructure, mechanical and thermal properties of ultrafine-grained Al2024–TiC-GNPs nanocomposite

Abstract

Al matrix composites (AMCs) have gained tremendous interest in the past decades due to their lightweight, superior mechanical and other physical properties. In this study, an ultrafine-grained Al2024/1 wt% TiC/1 wt% graphene nanoplatelets (GNPs) nanocomposite was fabricated through powder metallurgy. Synergetic effects of TiC and GNPs on the microstructural characteristics, mechanical properties and thermal conductivity were investigated in comparison with those of the matrix and TiC or GNPs singly reinforced Al2024 matrix nanocomposites. The Al2024/1 wt% TiC/1 wt% GNPs nanocomposite showed significantly improved mechanical properties with the compression yield strength of 370.2 MPa, ultimate compressive strength of 615.8 MPa and fracture strain of 8.6%, indicating a superior balance in the strength and ductility over TiC or GNPs singly reinforced Al matrix composite, since the distributions of both the TiC and GNPs in Al2024/1 wt% TiC/1 wt% GNPs nanocomposite were improved significantly. The significant mechanical property improvements are attributed to the synergistic reinforcing contributions from TiC and GNPs. The thermal conductivity of Al2024/1 wt% TiC/1 wt% GNPs nanocomposite stables at 55.0 W∙m-1∙K-1 without a further decrease compared with the composite singly reinforced with GNPs.