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Highlights • A new Ti-based BMGC with the composition of Ti 57.3 Zr 19.6 Cu 4.7 Ni 2.8 Be 12 Nb 3.6 was developed. • The composite shows large homogeneous ductility and significant work-hardening capacity. • The toughening mechanism is a combined effect of stress-induced martensitic transformation and mechanical twinning. Abstract A new Ti-based BMGC with excellent tensile plasticity and significant work-hardening capacity was successfully developed. The microstructure, mechanical behaviors and toughening mechanisms were investigated in details by SEM, XRD, TEM and Nano-indentation. It is found that the stress-induced martensitic transformation from β to α″ phase and the mechanical twinning in the α″ phase combined to account for these mechanical behaviors. The current work offers a new perspective for developing in situ dendrite reinforced BMGCs with improved homogeneous ductility and significant work-hardening capacity. [ABSTRACT FROM AUTHOR]

Up to now, few work has concerned about the composition design strategy in the field of in-situ dendrite bulk metallic glass composites (BMGCs) for the difficulty to mediate single element in the multi-component system. In this work, an innovative composition design strategy was proposed, and a novel series of in-situ β dendrite reinforced Ti-based BMGCs were prepared. It was found that the real composition of the in-situ formed dendrites and amorphous phase is well consistent with the designed one. Accordingly, the dendrite composition is tailored monotonically and precisely, while the composition and volume fraction keep similar for the amorphous matrix in the composites. The microstructure of the dendrites and the mechanical properties and mechanisms of the overall composites are essentially controlled by the dendrite composition. According to the corresponding deformation mechanisms which transform from stress-induced martensitic transformation and mechanical twinning to dislocation slip, these alloys can be classified into two groups: the stress-induced martensitic transformation type and the none-phase transformation type. The composition design strategy proposed in this work and the correlation between the dendrite composition and the mechanical mechanisms may provide useful guidance for the development of in-situ β dendrite reinforced BMGCs with optimized mechanical properties. [ABSTRACT FROM AUTHOR]

A novel series of in - situ dendrite Ti-based bulk metallic glass composites (BMGCs) were obtained. The Mo content of the dendrites monotonically increases from nil to 10.5 at% while the dendrite volume fraction and the composition of the amorphous matrix remain nearly invariant. It was found that the mechanical behaviors varied tremendously simply by changing the Mo content. Thus, the correlation between the composition and the mechanical behaviors under tension has been determined for in - situ dendrite Ti-based BMGCs for the first time. [ABSTRACT FROM AUTHOR]