Exploring the Feasibility of Laser Powder Bed Fusion for Graphene Reinforced Aluminum Matrix Composites: From In-Situ Reactions to Microstructure and Performance

This study investigates the potential enhancement of electrical and nanohardness properties in aluminum (Al) alloys through the incorporation of graphene. A binary Al alloy, AlSi12, was mixed with 0.5 wt% graphene using ball milling. The composite powder was then used in laser powder bed fusion (L-PBF) to fabricate samples. Electrical conductivity and nanohardness were measured to assess the properties of the composite compared to monolithic AlSi12. Microstructural analysis was conducted using scanning transmission electron microscopy (STEM) and energy dispersive spectroscopy (EDS). The results reveal that while the addition of graphene slightly reduces electrical conductivity due to the transformation of a large portion of the starting graphene to Al4C3 during processing, it enhances nanohardness through the presence of surviving graphene and nano sized Al4C3 carbides with higher hardness than the unreinforced AlSi12 matrix.