Comparison of mechanical behavior between bulk and ribbon Cu-based metallic glasses

As-cast bulk and as-spun ribbon Cu(60)Zr(30)Ti(10) metallic glasses were characterized using differential- scanning calorimetry and instrumented nanoindentation. Two alloys show a significant difference in the amount of free volume, which is attributed to the difference in a cooling rate, while exhibiting a similar serrated plastic flow. Atomic-force-microscopy observations demonstrate the pile-ups containing shear bands around the indents in both alloys. The as-cast bulk alloy has higher hardness and elastic modulus than the as-spun ribbon alloy. The difference in the strengths of two alloys may be related to the different amount of free volume. The strength seems to be more sensitive to a cooling rate during solidification than the plastic-flow behavior in the Cu(60)Zr(30)Ti(10). (c) 2006 Elsevier B.V. All rights reserved.