Synthesis and characterisation of graphene-reinforced AA 2014 MMC using squeeze casting method for lightweight aerospace structural applications

Abstract

The need for lightweight materials towards aerospace has increased prominently. This paper focuses on introducing a novel reinforcement mixture of graphene with Al 2014 powder synthesised through ball milling technique. The synthesized powder was utilized as a reinforcement to fabricate Al 2014 based MMCs through squeeze casting technique. The results exhibited that Al 2014 mixture with embedded and interlocked 2D-Grnp (2.517 g/cm3) matched the density of the matrix metal (2.771 g/cm3) that facilitated homogeneous dispersion of 2D-Grnp and solved the dispersion problems during stir casting. As a result, AA 2014 embedded with 2D-Grnp acted as a carrier to homogeneously disperse combined with the squeeze casting process leading to the production of homogeneously reinforced MMC. This can be considered as a potential fabrication route for the launch vehicle super lightweight fuel tank (SLWT) structural application. The final casted plate after T6 heat treatment with 0.5 wt% 2D-Grnp exhibited an improved tensile strength of 361 MPa (52% higher than the monolithic 2014 aluminium alloy) with total elongation of 21% and improved hardness of 119 HRB (45.5 % increase). Furthermore, SEM and TEM results exhibited that squeeze casting led to enhanced interfacial bonding between the 2D-Grnp and Al 2014.