Interactions between plastic deformation and precipitation in Aluminium alloys: A crystal plasticity model
Interactions between plastic deformation and precipitation in Aluminium alloys: A crystal plasticity model
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DOI：
10.1016/j.actamat.2023.118735
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发表时间：
2023-02-07
期刊：
影响因子：
9.4
通讯作者：
Shanthraj, Pratheek
中科院分区：
文献类型：
--
作者：
Bignon, Madeleine;Ma, Ziyu;Shanthraj, Pratheek
本文提出了铝合金动态析出的晶体塑性模型。它既考虑到一个不断发展的沉淀物分布的位错滑移的临界应力的影响，和沉淀动力学的变形的加速效应。在晶体塑性本构关系中考虑了析出相对变形行为的影响。变形对沉淀动力学的影响是模拟时空使用多类沉淀动力学模型（KWN）纳入变形通过加速溶质扩散所造成的过量空位的生产的影响。该模型被应用于在150 ℃下变形的预时效AA7075合金中的可剪切沉淀物的生长和粗化，这对应于工业上相关的生产。本文首先探讨了动态析出对拉伸行为的影响，表明动态析出可能是负责分别为2%的应变和50 MPa的均匀伸长率和拉伸应力的增益手头的情况下。动态沉淀的塑性应变不均匀性的发展的影响进行了讨论。该模型演示了如何在沉淀物分布的空间不均匀性可能在变形过程中发展，以及如何这些不均匀性与应变不均匀性的发展。预测了静态和动态时效条件下的析出相分布，并进行了比较，讨论了织构的影响。
This work presents a crystal plasticity model for dynamic precipitation in aluminium alloys. It takes into account both the influence of an evolving precipitate distribution on the critical stress for dislocation glide, and the accelerating effect of deformation on precipitation kinetics. The effect of precipitates on deformation behaviour is integrated into the crystal plasticity constitutive law. The effect of deformation on precipitation kinetics is modelled spatio-temporally using a multi-class precipitation kinetic model (KWN) incorporating the effect of deformation through accelerated solute diffusion caused by the production of excess vacancies. The model is applied to growth and coarsening of shearable precipitates in pre-aged AA7075 alloy under deformation at 150 degrees C, which corresponds to an industrially relevant production. This paper first explores the influence of dynamic precipitation on the tensile behaviour, showing that dynamic precipitation might be responsible for a gain in uniform elongation and tensile stress of respectively 2% strain and 50 MPa for the case at hand. The influence of dynamic precipitation on the development of plastic strain heterogeneities is discussed. The model demonstrates how spatial heterogeneities in precipitate distribution may develop during deformation, and how these heterogeneities correlate with the development of strain heterogeneities. The precipitate distributions obtained under static or dynamic ageing are predicted and compared with each other, and the influence of texture is discussed.