预变形对Al-Li-S4合金时效蠕变的影响规律及其本构建模（英文）

发布时间：2018-06-27 07:01

本文选题：Al-Li-S合金 + 时效蠕变　；参考：《Transactions of Nonferrous Metals Society of China》2015年05期

【摘要】：以Al-Li-S4合金为研究对象,开展其在不同预变形量、不同时效温度和试验应力下的单向拉伸蠕变试验,获得Al-Li-S4合金在时效成形基本热力条件下的时效蠕变行为和预变形对其形变、力学性能和显微组织的影响规律。结果表明:试样预变形量越大,蠕变第一阶段持续时间越短,蠕变第二阶段的稳态蠕变速率越大,最终的蠕变应变量越大,但在试验参数范围内仍小于未经预变形处理试样的蠕变应变量;TEM结果显示,引入预变形对T1相和θ′相析出有一定的促进作用并能显著促进析出相的细小弥散分布,同时抑制δ′相的析出,从而改善合金的力学性能。建立了能够反映时效机制、应力和预变形影响的蠕变时效统一本构模型,该模型的拟合结果对实验数据有较好的回归效果。
[Abstract]:The uniaxial tensile creep tests of Al-Li-S4 alloy under different pre-deformation amounts, different aging temperatures and experimental stresses were carried out. The aging creep behavior and pre-deformation of Al-Li-S4 alloy under the basic thermal conditions of aging forming were obtained. The influence of mechanical properties and microstructure. The results show that the larger the sample pre-deformation, the shorter the duration of the first stage of creep, the greater the steady state creep rate of the second stage of creep, and the greater the final creep strain. However, in the range of test parameters, the results of TEM show that the introduction of pre-deformation can promote the precipitation of T1 phase and 胃 'phase, and can obviously promote the fine dispersion distribution of precipitated phase. At the same time, the precipitation of 未 'phase was inhibited and the mechanical properties of the alloy were improved. A unified constitutive model of creep aging which can reflect the effects of aging mechanism stress and pre-deformation is established. The fitting results of the model have a good regression effect on the experimental data.
【作者单位】：中南大学机电工程学院;中南大学高性能复杂制造国家重点实验室;
【基金】：Project(2014CB046602)supported by the National Basic Research Program of China Project(51235010)supported by the National Natural Science Foundation of China
【分类号】：TG146.21;TG115.5

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