Evaluating the textural and mechanical properties of an Mg-Dy alloy processed by high-pressure torsion
Evaluating the textural and mechanical properties of an Mg-Dy alloy processed by high-pressure torsion
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DOI：
10.1016/j.jallcom.2018.11.109
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发表时间：
2019-03-25
影响因子：
6.2
通讯作者：
Langdon, Terence G.
中科院分区：
文献类型：
--
作者：
Hanna, Abdelkader;Azzeddine, Hiba;Langdon, Terence G.
Mg-0.41Dy（wt.采用X射线衍射、电子背散射衍射和维氏显微硬度测量等方法研究了高压扭转（HPT）15圈时合金圆盘中心、径向中点和边缘的织构、显微组织和显微硬度。在光盘的中心的纹理的特征在于由一个典型的弱基底纤维，而在两个中点和边缘的光盘有一个强大的基底纹理的c轴的大多数晶粒是偏离剪切方向15度。经过15次HPT旋转，获得了晶粒尺寸约为0.75 μ m的几乎均匀的超细晶组织。在这三个位置的显微硬度值增加的匝数，达到最大值，然后下降到一个较低的稳态水平在大应变。结果表明，除了位错和晶粒尺寸硬化外，织构强化对变形早期硬化的快速增加有显著贡献。(C)2018 Elsevier B. V.版权所有。
Samples of an Mg-0.41Dy (wt. %) alloy were severely deformed by high-pressure torsion (HPT) at room temperature up to 15 turns and the texture, microstructure and microhardness values in the centres, mid-radial points and edges of the HPT-deformed discs were investigated using X-ray diffraction, Electron BackScatter Diffraction and Vickers microhardness measurements. The textures in the centres of discs were characterized by a typical weak basal fiber whereas at both the mid-points and edges of the discs there was a strong basal texture where the c-axis of most grains was shifted 15 degrees away from the shear direction. An almost homogeneous ultrafine-grained structure with a grain size of about 0.75 mu m was achieved after 15 HPT turns. The microhardness values in these three positions increased with increasing numbers of turns, reached a maximum and then decreased to a lower steady-state level at large strains. In addition to dislocation and grain size hardening, the results show that texture strengthening contributes significantly to the rapid increase in hardening in the early stages of deformation. (C) 2018 Elsevier B.V. All rights reserved.