Structural enthalpy relaxation in the glass transition range
Structural enthalpy relaxation in the glass transition range
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DOI：
10.1016/0921-5093(94)90211-9
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发表时间：
1994-05
期刊：
影响因子：
6.4
通讯作者：
B. Zappel;F. Sommer
中科院分区：
文献类型：
--
作者：
B. Zappel;F. Sommer
用差示扫描量热法测量了Al_(30)La_(50)Ni_(20)和Al_(15)Ni_(25)Zr_(60)合金在亚稳玻璃态和过冷液态之间的热容随温度和时间的变化关系。用分步加热法得到了松弛玻璃态、过冷态和结晶态的最精确热容。在恒定升温速率条件下，利用热机械分析仪进行了粘性流动测量。在Tg−90K到Tg和Tg+20K温度范围内，观察到了两种Arrhenius型温度依赖关系，给出了淬火样品的粘性流动活化能。
The temperature and time dependence of the heat capacity of Al30La50Ni20and Al15Ni25Zr60alloys is measured between the metastable glassy and undercooled liquid states through the glass transition temperatureTgby differential scanning calorimetry. The most precise heat capacities for the relaxed glassy, the undercooled liquid and the crystalline states are obtained using the stepwise heating method. Viscous flow measurements under constant heating rate conditions are carried out with the aid of a thermomechanical analyser. Two Arrhenius-type temperature dependences of the viscosity in the temperature ranges fromTg− 90 K toTgand fromTg+ 20 K were observed, yielding activation energies of as-quenched samples for viscous flow.