Stress-dependent recovery of point defects in deformed aluminum: an acoustic-damping study
Stress-dependent recovery of point defects in deformed aluminum: an acoustic-damping study
复制标题
变形铝中点缺陷的应力依赖性恢复：声阻尼研究
DOI：
10.1016/s1359-6454(99)00251-7
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发表时间：
1999
期刊：
影响因子：
9.4
通讯作者：
H. Ledbetter
中科院分区：
文献类型：
--
作者：
H. Ogi;A. Tsujimoto;M. Hirao;H. Ledbetter
用剪切波衰减和相速度研究了99.99%多晶铝中点缺陷扩散对位错的应力依赖性。通过保持变形后的应力，衰减和速度接近它们的非应力值。在施加15兆帕的压缩应力后，保持应力在0到12兆帕之间变化。在Granato-Hikata-Lücke理论中引入了与时间无关的衰减和应力引起的速度变化，首次建立了点缺陷向位错扩散引起的衰减和速度变化。测量结果与修正后的理论符合得很好。恢复率的应力依赖关系被解释为点缺陷向位错扩散的迁移能的降低，并计算了单轴应力下的激活体积。使用电磁声谐振(EMAR)进行测量。由于非接触和高度敏感，EMAR允许详细测量卸载-保持应力序列中的衰减和速度演变。
The stress dependence of point-defect diffusion to dislocations in a 99.99% polycrystalline aluminum was studied using shear-wave attenuation and phase velocity. By holding the stress after deformation, attenuation and velocity approach their nonstressed values. The holding stress was varied between 0 and 12 MPa, after applying a 15 MPa compressive stress. Time-independent attenuation and stress-induced velocity change were introduced into the Granato–Hikata–Lücke theory, which first established the change of attenuation and velocity caused by the point-defect diffusion to dislocations. Good agreement was found between measurements and the modified theory. The stress dependence of the recovery rate was interpreted as a reduction of the migration energy of point defects diffusing to dislocations, and the activation volume was calculated for uniaxial stress. Electromagnetic acoustic resonance (EMAR) was used for the measurements. Being noncontact and highly sensitive, EMAR permitted detailed measurement of the attenuation and velocity evolutions during the unloading–holding stress sequence.