Prediction of Static Recrystallisation after Extrusion of Shaped Aluminium Sections
Prediction of Static Recrystallisation after Extrusion of Shaped Aluminium Sections
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异形铝型材挤压后静态再结晶的预测
DOI：
10.4028/www.scientific.net/msf.467-470.407
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
T. Sheppard
中科院分区：
文献类型：
--
作者：
Z. Peng;T. Sheppard
当挤出物穿过模具时，挤出物在不连续处经历大的变形，从而导致与挤出物的其余部分相比时平均变形参数的相当大的修改。因此，结构的分布极不均匀。参考再结晶过程的经验和物理模型表明，在通常在变形过程之后进行固溶处理和时效的那些合金中，成核和生长在这些位置处将不同。由于静态重结晶对挤出物的许多性质具有显著影响，因此必须提供预测这些变化的方法。在所介绍的工作中，基于位错密度、亚晶粒尺寸和取向差的物理模型被集成到商业有限元代码FORGE 2 ®和FORGE 3 ®中，以研究微观结构的变化。以轴对称挤压和异形挤压为例进行了分析。研究了影响静态再结晶的亚结构的演变。比较了轴对称挤压和异形挤压的冶金行为。预测结果与实验测量结果吻合较好。给出了等效应变、温度补偿应变速率和温度的分布，以帮助解释。
Extrusions experience large deformations at discontinuities when they traverse the die land, leading to considerable modifications to the average deformation parameters when compared to the remainder of the extrusion. The distribution of structure is therefore greatly inhomogeneous. Reference to both empirical and physical models of the recrystallisation process indicate that nucleation and growth will differ at these locations in those alloys that are usually solution treated and aged subsequent to the deformation process. Since static recrystallisation has a significant influence on many of the properties of the extrudate, it is therefore essential to provide the methodology to predict these variations. In the work presented, a physical model based on dislocation density, subgrain size and misorientation is integrated into the commercial FEM codes, FORGE2® and FORGE3® to study the microstructure changes. Axi-symmetrical and shape extrusion are presented as examples. The evolution of the substructure influencing static recrystallisation is studied. The metallurgical behaviour of axi-symmetric extrusion and that of shape extrusion are compared. The predicted results show good agreement with experimental measurement. The distribution of equivalent strain, temperature compensated strain rate and temperatures are also presented to aid in interpretation.