Understanding on toughening mechanism of bioinspired bulk metallic glassy composites by thermal spray additive manufacturing

Abstract Toughening mechanism of bioinspired bulk metallic glassy composites (BMGCs) reinforced with various volume fractions of ductile stainless-steel (SS) phase fabricated via newly developed thermal spray additive manufacturing was investigated. Microstructure characterizations and nanoindentation suggested a strong interface-bonding along with nanoscale compositional gradient formed between the metallic glass and SS phases. Finite element modelling and theoretical analysis revealed that the increase in toughness arose from the nacre-like soft/hard phase configuration, which exhibits the effective stress-shielding effect against crack propagation, thus mitigating stress concentration and blocking crack propagation.