Simultaneously enhancing the strength and plasticity of Ti-based bulk metallic glass composites via microalloying with Ta

Abstract

Characteristics of deformation-induced transformation under loading dictate the mechanical performance of TRIP (transformation-induced plasticity)-reinforced bulk metallic glass composites (BMGCs), which have shown great potential as engineering materials. Here, we report that the addition of 0.3 at.% Ta in the Ti45Cu41Ni9Zr5 alloy could induce the formation of uniform glassy composite structure with B2-(Ti,Zr)(Ni,Cu) precipitates. More interestingly, nanosized A2-(Ti,Zr)(Ni,Cu) particles also formed inside B2 grains which effectively impede rapid propagation of martensite plates and lead to the formation of multi-oriented martensites, eventually homogenizing the involved plastic flow during deformation-induced transformation. Consequently, high fracture strength (∼3000 MPa), large plasticity (∼25%) and pronounced work-hardening ability were achieved.