Microvoid coalescence-mediated toughening in B₄C@B₂O₃/Al composites via interfacial nanoamorphous layer modification

A nanoamorphous B₂O₃ layer was successfully introduced at the interface of B₄C/Al composites, leading to a significant enhancement in ductility without sacrificing strength. This improvement in ductility is attributed to the microvoid coalescence-like fracture mechanism observed during in-situ TEM tensile testing. The microvoids nucleate from point defects within the interfacial amorphous layer. As a result, a zig-zag fracture path forms, effectively dissipating energy and contributing to the enhanced ductility. These findings offer critical insights into the design of B₄C/Al composites with an optimal balance of strength and ductility.