Tailoring of in situ Ti-based bulk glassy matrix composites with high mechanical performance

In this study, we developed ductile dendrite-reinforced composites in the Ti-Zr-Ni-Cu-Be-(Nb) system. Although in situ composites have been successfully obtained by optimizing alloy composition and cooling rate, plasticity does not always occur. Only when the size, distribution, and elastic constants of the constituent phases are properly controlled, i.e. by creating homogeneously distributed dendrites with lower shear modulus than the glassy matrix, the composites exhibit large plasticity. By controlling the microstructural length scale and by tuning the intrinsic elastic constants of the constituent phases Ti-based bulk glassy matrix composites with good mechanical performance (high yield strength of ∼1.7 GPa and large plasticity of ∼25%) have been achieved.