Improved reinforcing efficiency of reduced graphene oxide in aluminum matrix composites produced through flake self-assembly methods

Preparing graphene-reinforced aluminum matrix composites requires balancing graphene's structural integrity and dispersion within the Al matrix . In this study, 5.0 vol% graphene oxide (GO)-Al powders were fabricated using flake self-assembly, which involves powder self-assembly and low-speed ball milling (LSBM). The mixed GO-Al powders, maintaining minimal structural damage, were densified using spark plasma sintering (SPS) followed by hot extrusion . Results showed that reduced graphene oxide (RGO) was dispersed along Al grain boundaries or within Al grains. Consequently, the yield strength (YS) and ultimate tensile strength (UTS) of the extruded RGO/Al composite achieved values of 291 MPa and 303 MPa, respectively, which represent enhancements of 4.6 and 3.8 times compared to the properties of the extruded Al matrix. In contrast to previous work, the improved tensile strength and increased RGO reinforcing efficiency ( R ) are attributed to the uniform dispersion of RGO with minimal structural damage. • The dispersion of 5.0 vol% GO into Al powders was accomplished using powder assembly and low-speed ball milling. • Enhanced load transfer between RGO sheets and the Al matrix was observed through in-situ TEM. • The extruded 5.0 vol% RGO/Al composite exhibited E of 85 GPa, YS of 291 MPa, and UTS of 303 MPa. • The UTS increase and RGO reinforcing efficiency for the 5.0 vol% RGO/Al composite were 223 MPa and 55.8 %, respectively.