Daróczi Lajos, Elrasasi Tarek Yousif, Arjmandabasi Talaye, Tóth László Zoltán, Veres Bence, Beke Dezső László
Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary.
Department of Physics, Faculty of Science, Benha University, Benha 13518, Egypt.
Materials (Basel). 2021 Dec 28;15(1):224. doi: 10.3390/ma15010224.
In this study, acoustic emission (AE) measurements on polycrystalline tin as a function of temperature at different driving rates under compression were carried out. It is shown that there is a definite difference between the acoustic emission characteristics belonging to twinning (low temperatures) as well as to dislocation slip (high temperatures). The stress averaged values of the exponents of the energy probability density functions decreased from ε = 1.45 ± 0.05 (-60 °C) to ε = 1.20 ± 0.15 (50 °C) at a driving rate of ε=0.15 s-1, and the total acoustic energy decreased by three orders of magnitude with increasing temperature. In addition, the exponent in the scaling relation ( is the area and is the duration) also shows similar temperature dependence (changing from = 1.78 ± 0.08 to = 1.35 ± 0.05), illustrating that the avalanche statistics belong to two different microscopic deformation mechanisms. The power law scaling relations were also analyzed, taking into account that the detected signal is always the convolution of the source signal and the transfer function of the system. It was obtained that approximate values of the power exponents can be obtained from the parts of the above functions, belonging to large values of parameters. At short duration times, the attenuation effect of the AE detection system dominates the time dependence, from which the characteristic attenuation time, , was determined as ≅ 70 μs.
在本研究中，对多晶锡在压缩状态下不同驱动速率时随温度变化的声发射（AE）进行了测量。结果表明，属于孪晶（低温）以及位错滑移（高温）的声发射特性之间存在明显差异。在驱动速率ε = 0.15 s⁻¹时，能量概率密度函数指数的应力平均值从ε = 1.45 ± 0.05（-60°C）降至ε = 1.20 ± 0.15（50°C），并且随着温度升高，总声能降低了三个数量级。此外，标度关系 （ 是面积， 是持续时间）中的指数 也表现出类似的温度依赖性（从 = 1.78 ± 0.08变为 = 1.35 ± 0.05），这表明雪崩统计属于两种不同的微观变形机制。考虑到检测到的信号始终是源信号与系统传递函数的卷积，还对幂律标度关系进行了分析。结果得出，可以从上述函数中属于大参数值的部分获得幂指数的近似值。在短持续时间内，AE检测系统的衰减效应主导了时间依赖性，据此确定特征衰减时间 约为70 μs。
