共查询到20条相似文献,搜索用时 21 毫秒
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Effect of Initial Annealing Temperature on Microstructural Development and Microhardness in High‐Purity Copper Processed by High‐Pressure Torsion 下载免费PDF全文
Saleh N. Alhajeri Abdulla I. Almazrouee Khaled J. Al‐Fadhalah Terence G. Langdon 《Advanced Engineering Materials》2018,20(1)
The effect of the initial annealing temperature on the evolution of microstructure and microhardness in high purity OFHC Cu is investigated after processing by HPT. Disks of Cu are annealed for 1 h at two different annealing temperatures, 400 and 800 °C, and then processed by HPT at room temperature under a pressure of 6.0 GPa for 1/4, 1/2, 1, 5, and 10 turns. Samples are stored for 6 months after HPT processing to examine the self‐annealing effects. Electron backscattered diffraction (EBSD) measurements are recorded for each disk at three positions: center, mid‐radius, and near edge. Microhardness measurements are also recorded along the diameters of each disk. Both alloys show rapid hardening and then strain softening in the very early stages of straining due to self‐annealing with a clear delay in the onset of softening in the alloy initially annealed at 800 °C. This delay is due to the relatively larger initial grain size compared to the alloy initially annealed at 400 °C. The final microstructures consist of homogeneous fine grains having average sizes of ≈0.28 and ≈0.34 µm for the alloys initially annealed at 400 and 800 °C, respectively. A new model is proposed to describe the behavior of the hardness evolution by HPT in high purity OFHC Cu. 相似文献
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Microstructure,Phase Composition,and Thermal Stability of Two Zirconium Alloys Subjected to High‐Pressure Torsion at Different Temperatures 下载免费PDF全文
Stanislav. O. Rogachev Sergey A. Nikulin Andrey B. Rozhnov Mikhail V. Gorshenkov 《Advanced Engineering Materials》2018,20(9)
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目的 研究轧态Al-Zn-Mg-Cu合金在高压扭转变形中组织性能的演变规律。方法 在120 ℃下,对Al-Zn-Mg-Cu合金进行扭转1, 5, 10圈的高压扭转实验,采用X射线衍射、光学显微镜、扫描电镜和拉伸实验对Al-Zn-Mg-Cu合金在高压扭转变形过程中组织及力学性能进行分析。结果 在高压扭转变形中,合金中晶粒显著细化。随着扭转圈数的增加,晶粒达到亚微米级,沿着高压扭转的方向分布。同时,合金中第二相含量减少,间距增大。合金的最强衍射峰由(220)转变为(111),呈现{111}<110>择优取向,位错密度随着扭转圈数的增加而增加。合金的强度和伸长率随着扭转圈数的增加而增加,扭转至10圈后,合金的强度提高了16.87%,伸长率从8.67%提升到10.65%。结论 高压扭转变形细化了合金的晶粒,提高合金强度的同时改善了合金的塑性。 相似文献
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Using Post‐Deformation Annealing to Optimize the Properties of a ZK60 Magnesium Alloy Processed by High‐Pressure Torsion 下载免费PDF全文
Seyed A. Torbati‐Sarraf Shima Sabbaghianrad Terence G. Langdon 《Advanced Engineering Materials》2018,20(2)
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目的研究TC4钛合金高压扭转变形过程,得到最佳的变形条件。方法以不同高径比的TC4钛合金饼坯为研究对象,利用Deform-3D数值模拟软件模拟其高压扭转变形过程,分析高压扭转变形过程中的变形情况以及等效应变分布规律,分析摩擦因数、变形温度、轴向压力对钛合金高压扭转变形过程的影响并对其进行优化。结果摩擦因数对高压扭转变形过程的影响比较大,当摩擦因数达到1时,高压扭转变形过程相对容易进行。变形温度对高压扭转变形过程的影响不是很明显,不过温度越高,变形越容易进行。轴向压力越大,变形越不均匀,轴向压力选择314 kN为最佳变形条件。结论摩擦因数较大,利于TC4高压扭转变形过程。变形温度对高压扭转变形过程影响不大。轴向压力选择适当利于高压扭转变形过程。 相似文献
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