Extended application of a unified creep-ageing constitutive model to multistep heat treatment of aluminium alloys
Extended application of a unified creep-ageing constitutive model to multistep heat treatment of aluminium alloys
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DOI：
10.1016/j.matdes.2017.03.023
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发表时间：
2017-05-15
影响因子：
8.4
通讯作者：
Rong, Qi
中科院分区：
文献类型：
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作者：
Li, Yong;Shi, Zhusheng;Rong, Qi
将新近发展的Al-Cu-Li合金（AA 2050-T34）蠕变-时效统一本构模型成功地推广到铝合金多步热处理的应用中，包括简单和复杂硬化演变的自然和人工时效以及不同初始回火条件下的蠕变-时效。基于统一的蠕变时效本构模型，提出了一种适用于自然时效和人工时效的时效硬化模型，给出了一般热处理条件下铝合金微观和宏观变量的初始值和平衡值的确定方法。通过统一规范化的微观结构变量在整个多步热处理，该模型能够预测的简单和复杂的各种铝合金在时效和蠕变时效过程中的强化演变。对一些典型的可热处理铝合金，包括2xxx（Al-Cu-Mg和Al-Cu-Li）和7 xxx（Al-Zn-Mg）合金在淬火态、自然时效态（T3/T4）和峰值时效态（T6/T8）初始回火条件下的自然时效、人工时效和蠕变时效进行了大量的实例研究。实验和模拟结果之间取得了很好的一致性。(C)2017爱思唯尔有限公司版权所有。
A recently developed unified constitutive model for creep-ageing of an Al-Cu-Li alloy (AA2050-T34) has been successfully extended to applications of multistep heat treatments of aluminium alloys, including natural and artificial ageing with simple and complex hardening evolution and creep-ageing with different initial temper conditions. An age hardening model for both natural and artificial ageing was proposed based on the unified creep ageing constitutive model and methods to determine the initial and equilibrium values of both micro and macro variables of aluminium alloys under general heat-treated conditions were presented. By unifying normalised microstructural variables throughout the multistep heat treatments, the model was able to predict both the simple and complex strengthening evolution of various aluminium alloys during ageing and creep-ageing. A number of case studies were carried out for natural ageing, artificial ageing and creep-ageing of some typical heat-treatable aluminium alloys, including 2xxx (Al-Cu-Mg and Al-Cu-Li) and 7xxx (Al-Zn-Mg) alloys with as-quenched, naturally-aged (T3/T4) and peak-aged (T6/T8) initial temper conditions. Excellent agreement has been achieved between experimental and simulation results. (C) 2017 Elsevier Ltd. All rights reserved.