Research on microstructure and properties of Gr@Cu reinforced 6061 aluminum matrix composites

Graphene serves as an attractive reinforcement phase owing to its outstanding electrical conductivity and mechanical strength. However, the brittle phases formed at graphene/aluminum interfaces and particle agglomeration issues restrict further improvement of composite performance. This study employs ball-milling technology to fabricate graphene-coated copper (Gr@Cu) particles as reinforcements, followed by preparing Gr@Cu reinforced aluminum matrix composites through combined ball-milling and powder metallurgy. We aim to investigate the influence of Gr@Cu content on microstructural evolution and mechanical properties. Experimental results reveal that Gr@Cu particles effectively refine the grain structure. The composites demonstrate gradual enhancements in yield strength, ultimate tensile strength, and hardness with increasing Gr@Cu content, while experiencing reduced elongation. At 2 wt% Gr@Cu addition, the composites achieve a yield strength of 162.5 MPa and an ultimate tensile strength of 238 MPa, showing 37.71% and 34.47% improvements, respectively, compared to the 6061 aluminum matrix. This research establishes a novel approach for developing aluminum matrix composites with balanced strength and ductility.