摘要
Pd_(40)Ni_(40)P_(20)(at.%)samples with different enthalpy states were fabricated through high-pressure torsion or sub-Tg annealing of the as-cast material.Subsequently,the underlying structural relaxation was studied by in-situ shear modulus measurements and modulated differential scanning calorimetry.The results show that high-pressure torsion leads to shear modulus softening and an increase of the nonreversible exothermic enthalpy,indicating a significant structural rejuvenation,while sub-Tg annealing causes shear modulus hardening and a decrease of the nonreversible exothermic enthalpy.The reversible endothermic effect which can reflect the fractional change of supercooled liquid with temperature was found to be almost identical for all samples,and independent of deformation or thermal history.The total heat flow can be well correlated with the shear modulus within the framework of interstitialcy theory.Furthermore,we demonstrate that the structural relaxation below Tg decouples into internal stress relaxation andβ-relaxation.In addition,this work indicates that the processes ofα-relaxation andβ-relaxation in the metallic glass are of similar structural origin but occur on different spatial scales.
基金
financial support by German Research Foundation under the grant No.W11899/29-1
the China Scholarship Council for its financial support
the financial support from Russian Science Foundation under the grant No.20-62-46003(measurements of the shear modulus and discussion on the results)。
