New centimeter-sized quaternary Ti-Zr-Be-Cu bulk metallic glasses with large glass forming ability

By replacing Be with Cu in ternary Ti-Zr-Be alloys, new centimeter-sized quaternary Ti-based bulk metallic glasses (BMGs) have been successfully synthesized in Ti41Zr25Be34−xCux (x = 2, 4, 6 and 8 at. %) and Ti45Zr20Be35−xCux (x = 2, 4, 6, 8 and 10 at. %) alloys. With the Cu addition, the glass-forming ability (GFA), the supercooled liquid range and the yield strength of the ternary Ti-Zr-Be glassy alloys are obviously improved. Among all the developed glassy alloys in the present study, the Ti41Zr25Be28Cu6 BMG has a critical diameter of 15 mm, which is the largest size in the quaternary Ti-based BMGs. The experimental results show that Cu is an effective element for improving the GFA of the Ti-Zr-Be glassy alloys.