Mechanical Properties of Hf-Based Metallic Glasses

The quasi-static and dynamic compression tests for Hf44.5Cu27Ni13.5Ti5Al10 metallic glass were done by MTS810 and split Hopkinson pressure bar (SHPB) in the range of strain rate of 10-4-103 s-1. The compressive stress-strain curves were obtained under varied strain rate and the fracture morphologies were studied by scanning electron microscopy. The experimental results show that the Hf44.5Cu27Ni13.5Ti5Al10 metallic glass does not have the strain rate sensitivity under quasi-static compression. The dimple structure and periodic corrugations with about 60 nm spacing can be observed at the fracture surfaces which consist of radical zone and fan-shaped zone. Under dynamic compression, the yield strength rapidly declines with rise of strain rate, the metallic glass has the strain rate sensitivity. The fracture surfaces show floccule structure with vein-like patterns. Further observation reveals that dynamic compression fracture surfaces exist three fracture morphology: branch-like patterns, vein-like patterns and molten agglomerates.