Ductility enhancement of a Ti-based bulk metallic glass through annealing treatment below the glass transition temperature

The effect of annealing treatment on mechanical properties has been investigated for a Ti-based bulk metallic glass (BMG). A series of compression tests as well as Vickers hardness tests has thus been performed at room temperature for the BMG specimens annealed in an Ar atmosphere at several temperatures near the glass transition temperature (Tg). The ductility under compression was found to increase up to about 42% without reducing the maximum strength, but with higher hardness values. Thermal properties were also analyzed by using a differential scanning calorimetry (DSC), while microstructures of annealed specimens were studied through X-ray diffraction (XRD) and also a high resolution transmission electron microscopy (HRTEM).

True stress vs. true strain curves obtained from compression tests for annealed specimens at 583 K and SEM image of annealed specimen for 30 min to the strains of 10%.Figure optionsDownload as PowerPoint slideHighlights
► Ti-based BMG has ductility by generating the secondary crystalline phases.
► Specimen was annealed at various times and temperatures near the Tg.
► Plasticity of specimen annealed at optimum condition is increased up to 42 %.
► That is very epochal value compared with previous monolithic BMG and BMG composite.