Materials Research Centre, Indian Institute of Science, Bangalore 560012, India.
Phys Rev Lett. 2011 Mar 11;106(10):106001. doi: 10.1103/PhysRevLett.106.106001. Epub 2011 Mar 8.
We address the long-standing problem of the origin of acoustic emission commonly observed during plastic deformation. We propose a framework to deal with the widely separated time scales of collective dislocation dynamics and elastic degrees of freedom to explain the nature of acoustic emission observed during the Portevin-Le Chatelier effect. The Ananthakrishna model is used as it explains most generic features of the phenomenon. Our results show that while acoustic emission bursts correlated with stress drops are well separated for the type C serrations, these bursts merge to form nearly continuous acoustic signals with overriding bursts for the propagating type A bands.
我们解决了在塑性变形过程中普遍观察到的声发射起源这一长期存在的问题。我们提出了一个框架来处理集体位错动力学和弹性自由度的广泛分离时间尺度,以解释在 Portevin-Le Chatelier 效应期间观察到的声发射的性质。我们使用 Ananthakrishna 模型,因为它解释了该现象的大多数通用特征。我们的结果表明,虽然与应力降相关的声发射爆发在 C 型锯齿形中很好地分开,但这些爆发在传播的 A 型带中合并成几乎连续的声信号,并具有压倒性的爆发。