Abnormal sub-Tg enthalpy relaxation in the CuZrAl metallic glasses far from equilibrium
Abnormal sub-Tg enthalpy relaxation in the CuZrAl metallic glasses far from equilibrium
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DOI：
10.1063/1.3556659
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发表时间：
2011-02-21
影响因子：
4
通讯作者：
Zhang, Chunzhi
中科院分区：
文献类型：
--
作者：
Hu, Lina;Yue, Yuanzheng;Zhang, Chunzhi
远离平衡的玻璃中的亚T-g焓弛豫（即，超淬火玻璃）通常表现为起始温度和焓恢复程度随着退火温度的增加而单调增加。本文报道了Cu_（45）Zr_（45）Al_（10）和Cu_（48）Zr_（48）Al_（4）玻璃在低于T-g时的反常三阶弛豫模式，当退火温度增加到临界值时，通常的单调增加被反转。这种异常的弛豫模式可以归因于在CuZrAl过冷液体中的化学不均匀性的程度高，并提出了在金属玻璃形成液体中的动态脆到强的转变的热力学证据。(C)2011年美国物理学会。[doi：10.1063/1.3556659]。
The sub-T-g enthalpy relaxation in glasses far from equilibrium (i.e., hyperquenched glasses) is usually manifested as a monotonic increase in both the onset temperature and the extent of enthalpy recovery with increasing the annealing temperature. Here we report an abnormal three-steplike relaxation pattern in hyperquenched Cu45Zr45Al10 and Cu48Zr48Al4 glasses below T-g, i.e., the usual monotonic increase is inverted when the annealing temperature increases to a critical value. This abnormal relaxation pattern could be attributed to the high extent of chemical heterogeneity in the CuZrAl supercooled liquids, and present a thermodynamic evidence for the dynamic fragile-to-strong transition in metallic glass-forming liquids. (C) 2011 American Institute of Physics. [doi:10.1063/1.3556659].