A quinary Ti–Zr–Hf–Be–Cu high entropy bulk metallic glass with a critical size of 12 mm

• A new quinary high entropy bulk metallic glasses (HE-BMG) has been developed.
• This HE-BMG has the largest critical size of 12 mm in the reported quinary HE-BMGs.
• This HE-BMG possesses a larger supercooled liquid region of 78 K than other HE-BMGs.
• This HE-BMG exhibits a relatively good plasticity (2.2 ± 0.1%) among the HE-BMGs.

A quinary Ti20Zr20Hf20Be20Cu20 high entropy bulk metallic glass (HE-BMG), with a critical diameter (Dc) of 12 mm—the largest size in the reported quinary high entropy alloys (HEAs), has been successfully prepared by copper mold casing. This novel HE-BMG possesses a supercooled liquid region ΔT (=Tx − Tg) of 78 K, indicating a better thermal stability than those of other HE-BMGs. In addition, the HE-BMG exhibits a relatively good compressive plasticity (2.2 ± 0.1%) among the HE-BMGs. The newly developed HE-BMG may offer insights for the indepth understanding of the fundamental issues associated with the glass formation and the unique structure-property relationship when combining the features of HEAs and BMGs together.