Effects of similar-element-substitution on the glass-forming ability and mechanical behaviors of Ti-Cu-Zr-Pd bulk metallic glasses

The Ti₄₁Cu₃₁Zr₁₀Pd₁₃ (at.%) metallic glasses are promising for bone-implantation applications due to their exceptional bio-compatibility. However, Pd, as a noble element, keeps the fabrication cost high and prevents the industrial sale production of these alloys. Searching for replacements with comparable glass-forming ability and ductility but lower cost turns out to be imperative. In this article, we used similar but less expensive elements to substitute Pd for such a goal. Specifically, 1-4 at.% Ni and Pt are incrementally used to replace Pd in the base alloy. Careful characterizations of the glass-forming ability and the compressive ductility suggest that the Ti₄₁Cu₃₆Zr₁₀Pd₁₀Ni₃ metallic glass retains both the glass-forming ability and the ductility, but cuts down the alloy cost by ∼22.66%. The Ti₄₁Cu₃₆Zr₁₀Pd₁₂Pt₁ metallic glass, despite no substantial trimming in the alloy cost, doubles the ductility and fairly maintains the glass-forming ability. The serrated flow is observed on the plastic flow of most metallic glasses investigated and is quantitatively studied in the framework of the self-organized criticality. Our work provides important insights on defining appropriate commercialization routes of Ti-based bulk metallic glasses.