Enhanced Tensile Properties of Graphene-Al5083 Composite Prepared by Hot Pressing and Hot Extrusion

Graphene, with outstanding mechanical properties of 1TPa of Young’s modulus and 130GPa of tensile strength, has been considered as an excellent reinforcement in composites. Graphene nanoplates (GNP) reinforced Al5083 alloy composites were successfully fabricated by powder metallurgy method. Flake-like Al5083 powder was firstly added into a GNP-alcohol solution and then dried in vacuum oven at 343 K for 5 h. The composite powders were sintered at 723K under pressure of 300 MPa for 1 h, followed by extrusion at 623 K. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed for microstructure characterization. Al4C3 cannot be observed in the composite, suggesting that there was no reaction occurred between GNP and Al matrix during the processing. Tensile test results revealed that the ultimate tensile strength and tensile elongation of 0.3wt.%GNP/Al5083 composites were 580MPa and 15%, respectively, showing optimal combination of strength and ductility. The relevant strengthening mechanisms of the composites were discussed.