Flow serrations of rejuvenation behaviour through cryogenic thermal cycling for Zr-based bulk metallic glass

ABSTRACT

Effects of cryogenic thermal cycling (CTC) on mechanical properties and serrated flow of the Zr_52.5Cu_17.9Ni_14.6Al₁₀Ti₅ bulk metallic glass were studied. The improved plasticity, a slightly reduced yield stress and abundant small serrations could be signs of rejuvenation. The high disorder degree result from rejuvenation increases the volume of shear transformation zones (STZs), and thus leads to the enhancement of plasticity. The larger plasticity of BMGs is realised through the superimposed effect of two favourable factors (CTC treatment and strain rate). In this case, the experimental failure threshold is far below the theoretical value. It provides a new idea for designing ductile BMGs.

KEYWORDS:

• Bulk metallic glass
• cryogenic thermal cycling treatment
• serrated flow
• failure threshold

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors would like to acknowledge the financial support of National Natural Science Foundation of China [grant number 52071229] and the Natural Science Foundation of Shanxi Province, China [grant numbers 201901D111105 and 201901D111114]. Z.W. would like to acknowledge the financial support of China Postdoctoral Science Foundation [grant number 2020M670708].