Grain size evolution simulation in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process
Grain size evolution simulation in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process
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DOI：
10.1179/1743284712y.0000000132
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发表时间：
2013-01-01
影响因子：
1.8
通讯作者：
Tekkaya, A. E.
中科院分区：
文献类型：
--
作者：
Foydl, A.;Segatori, A.;Tekkaya, A. E.
研究了AA 6082和AA 7020铝合金在热正挤压过程中的晶粒尺寸演变规律。本工作的目的是定义和实现的预测算法，该算法能够计算的过程中的有限元方法代码变形的晶粒形状的演变。挤出实验进行了两个层次：在缩小规模的调查和确定的预测方程和工业规模的验证开发的算法。在小规模挤压时，在三种不同温度、三种挤压比和两种冲压速度下对两种合金进行了完整的析因计划：立即对实验中的废弃物和挤压物进行淬火，以避免任何潜在的再结晶，从而允许测量过渡加工步骤。相反，在工业规模上，用两种不同的模具设计挤压7020合金，从而在不同的挤压比和应变路径下生产直径为20 mm的圆棒。有限元模拟最初验证了塑性研究，以建立一个准确的计算的材料流，然后实验和数值结果相结合，从而允许定义的晶粒演化模型，成功地集成和验证工业规模的试验。
The present paper investigates the grain size evolution in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process. The aim of the present work is the definition and implementation of a predictive algorithm that is able to compute the evolution of the grain shape during the process within the finite element method code Deform. Extrusion experiments were performed at two levels: at reduced scale for investigating and identifying the predictive equations and at industrial scale for validating the developed algorithm. At small scale extrusion, a complete factorial plan was performed for two alloys at three different temperatures, three extrusion ratios and two ram speeds: the discards and extrudates from the experiments were quenched immediately in order to avoid any potential recrystallisation, hence allowing measurements of transitional processing steps. At the industrial scale, instead, the 7020 alloy was extruded with two different die designs, thus producing a 20 mm diameter round bar under different extrusion ratios and strain paths. Finite element simulations were initially validated over visioplastic investigations in order to establish an accurate computation of the material flow, then experimental and numerical results were coupled, thus allowing the definition of the grain evolution model that was successfully integrated and validated on industrial scale trials.