Ti-Based Bulk Metallic Glasses with High Specific Strength

抄録

The glass forming ability of melt-spun Ti_65-xZr_xBe₁₈Cu₉Ni₈ (x = 0, 5, 10, 15) amorphous alloys have been investigated by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). With increasing Zr contents, x from 0 to 15, ΔT_x (= T_x − T_g), T_rg (= T_g/T_l) and γ (= T_x/(T_g + T_l)), where T_g = glass transition temperature, T_x = crystallization temperature and T_l = liquidus temperature, gradually increase from 35 to 40 K, from 0.558 to 0.621, and from 0.378 to 0.406, respectively. The Ti_65-xZr_xBe₁₈Cu₉Ni₈ (x = 10, 15) BMG cylinders with the diameter up to 6 mm are successfully fabricated by the injection casting method, exhibiting high Vickers hardness (681-700) and yield strength (2.0-2.1 GPa). Ti-Zr-Be-Cu-Ni alloys with >50 at% Ti content have higher specific strength than any other Ti-based BMGs reported so far.