In situ formation of uniformly dispersed Al₄C₃ nanorods during additive manufacturing of graphene oxide/Al mixed powders

A novel Al₄C₃ nanorod was synthesized through an in situ reaction between graphene oxide (GO) and Al powders during laser powder bed fusion (L-PBF). The few-layer GO sheets were prepared by a modified Hummers method and were mixed with Al powders by electrostatic self-assembly. After subsequent L-PBF processing, the GO reacted with Al atoms completely to form Al₄C₃ nanorods that had a mean diameter of ∼140 nm and length of ∼2.3 μm, displaying a higher aspect ratio than that made by traditional powder metallurgy. Observations of high-resolution transmission electron microscopy revealed that the Al₄C₃ was monocrystalline and intimately contacted with the Al matrix, consequently resulting in the noticeably enhanced mechanical performance of the composite. This work may offer significant guidance for designing and producing new high-specific-strength materials for structural applications.