Grain refinement in an AlEr alloy during accumulative continuous extrusion forming
Grain refinement in an AlEr alloy during accumulative continuous extrusion forming
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DOI：
10.1016/j.jallcom.2016.04.137
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发表时间：
2016-09
影响因子：
6.2
通讯作者：
N. Su;R. Guan;Xiang-Jie Wang;Yuxiang Wang;Wensen Jiang;H. Liu
中科院分区：
文献类型：
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作者：
N. Su;R. Guan;Xiang-Jie Wang;Yuxiang Wang;Wensen Jiang;H. Liu
采用累积连续挤压成形（ACEF）方法对Al单键0.2Er（wt%）合金进行了晶粒细化。利用电子背散射衍射（EBSD）和透射电镜（TEM）研究了Al单键Er合金在交流电场作用下的显微组织。结果表明，超细晶的形成是由大应变引起的连续动态再结晶（CDRX）引起的。随着应变的积累，LAGB逐渐引入并转化为HAGB，导致平均取向角增加。通过连续挤压成形工艺的多道次细化了合金的晶粒，Al单键0.2Er（wt%）合金的平均晶粒尺寸在4道次内从26.01 μm减小到1.3 μm。Al单键0.2Er（wt%）合金的平均晶粒尺寸小于纯铝。Al单键Er合金中析出相的形成，通过提高局部应变能，促进了CDRX形核，并通过限制晶界迁移，减缓再结晶晶粒的长大，使晶粒细化。
The grain of an Alsingle bond0.2Er alloy (wt%) was refined by accumulative continuous extrusion forming (ACEF). Microstructure of the Alsingle bondEr alloy subjected to ACEF was investigated through electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The results revealed that the formation of ultra-fine grains results from a type of continuous dynamic recrystallization (CDRX) that is induced by large strains. With the accumulation of strain, LAGBs gradually introduced and transformed into HAGBs, which leads to an increase in the average orientation angle. The micro-grain alloy is refined through repeated passes of the continuous extrusion forming process and the average grain size of the Alsingle bond0.2Er (wt%) alloy decreased from 26.01 μm to 1.3 μm in four passes. The Alsingle bond0.2Er (wt%) alloy had a smaller average grain size than that of pure aluminum. The formation of precipitates in Alsingle bondEr alloy can stimulate the nucleation of CDRX by increasing the local strain energy and slow the growth of recrystallization grains by limiting grain boundary migration that causing grain refinement.