Modelling of the flow behaviour of wrought aluminium alloys at elevated temperatures by a new constitutive equation
Modelling of the flow behaviour of wrought aluminium alloys at elevated temperatures by a new constitutive equation
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DOI：
10.1016/j.matdes.2013.09.013
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发表时间：
2014-02-01
影响因子：
8.4
通讯作者：
Spigarelli, S.
中科院分区：
文献类型：
--
作者：
El Mehtedi, M.;Musharavati, F.;Spigarelli, S.
研究了Al-0.7%Mg-0.4%Si（wt.%）合金的热加工性能通过在450-575 ℃温度范围内的扭转试验研究了铝合金。的合金的行为，在等效应力与等效应变方面，建模的修改形式的Hensel和Spittel本构方程。在这个新方程中，外加应力σ被sinh（alpha sigma）项所取代，其中alpha是一个常数。Hensel-Spittel方程的修正形式给出了一个很好的描述的流动曲线和应变速率敏感性的降低所观察到的流动应力，在一个给定的应变，随着应变速率的增加。然后，重写模型方程，明确包括描述应变速率的温度依赖性的阿克里先乌斯项。计算表明，在所考虑的应变范围内，热加工激活能从218 kJ mol（1）降低到198 kJ mol（1）。(C)2013爱思唯尔有限公司版权所有。
The hot working behaviour of an Al-0.7%Mg-0.4%Si (wt.%) aluminium alloy has been investigated by torsion testing in the 450-575 degrees C temperature range. The behaviour of the alloy, in terms of equivalent stress vs equivalent strain, was modelled by a modified form of the Hensel and Spittel constitutive equation. In this new equation, the applied stress sigma was replaced by the sinh(alpha sigma) term, where alpha was a constant. The revised form of the Hensel-Spittel equation gave an excellent description of the flow curves and of the decrease in the strain rate sensitivity of the flow stress observed, at a given strain, with increasing strain rate. The model equation was then rewritten to explicitly include the Arrhenius term describing the temperature dependence of strain rate. The calculation indicated that the activation energy for hot working decreased from 218 to 198 kJ mol (1) in the considered range of strain.(C) 2013 Elsevier Ltd. All rights reserved.