Improvement of bio-corrosion resistance for Ti₄₂Zr₄₀Si₁₅Ta₃ metallic glasses in simulated body fluid by annealing within supercooled liquid region

The effects of the nanocrystalline phases on the bio-corrosion behavior of highly bio-friendly Ti₄₂Zr₄₀Si₁₅Ta₃ metallic glasses in simulated body fluid were investigated, and the findings are compared with our previous observations from the Zr₅₃Cu₃₀Ni₉Al₈ metallic glasses. The Ti₄₂Zr₄₀Si₁₅Ta₃ metallic glasses were annealed at temperatures above the glass transition temperature, T_g, with different time periods to result in different degrees of α-Ti nano-phases in the amorphous matrix. The nanocrystallized Ti₄₂Zr₄₀Si₁₅Ta₃ metallic glasses containing corrosion resistant α-Ti phases exhibited more promising bio-corrosion resistance, due to the superior pitting resistance. This is distinctly different from the previous case of the Zr₅₃Cu₃₀Ni₉Al₈ metallic glasses with the reactive Zr₂Cu phases inducing serious galvanic corrosion and lower bio-corrosion resistance. Thus, whether the fully amorphous or partially crystallized metallic glass would exhibit better bio-corrosion resistance, the answer would depend on the crystallized phase nature.