Effect of transition metal elements (Cu, Ni, Co and Fe) on the mechanical properties of Ti-based bulk metallic glass composites

A series of Ti-based Ti₄₅Zr₂₅Nb₆Sn₂TM₅Be₁₇(at.%, TM = Cu, Ni, Co and Fe) BMG composites were studied to show the effect of transition metal elements on the microstructure, intrinsic properties and mechanical properties of Ti-based BMG composites. The research shows that the transition metal elements are distributed mainly in the glass-matrix, substitution of which influences significantly the Young's modulus and hardness of glass-matrix. Different from the load-bearing model, the yielding strength of the BMG composites relates highly to not only the yielding strength of the dendrite-phase but also that of the glass-matrix. The plasticity of the BMG composites is highly dependent on the average stress concentration factor of the dendrite-phase. A useful rule for preparing of BMG composite with high strength and excellent plasticity is herein proposed, where tailoring simultaneously the properties of dendrite-phase and glass-matrix is suggested to be a better choice to obtain a good compromise between strength and plasticity.