Dislocation dynamics modelling of the creep behaviour of particle-strengthened materials.
Dislocation dynamics modelling of the creep behaviour of particle-strengthened materials.
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DOI：
10.1098/rspa.2021.0083
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发表时间：
2021-06
期刊：
影响因子：
--
通讯作者：
Tarleton E
中科院分区：
文献类型：
--
作者：
Liu FX;Cocks ACF;Tarleton E
晶体材料的塑性变形是通过位错滑移发生的，强化是通过阻碍位错运动的障碍物来实现的。在相对较低的温度下，位错通过Orowan环、颗粒剪切、交叉滑移或这些机制的组合绕过颗粒。在高温下，原子的扩散变得明显，因此位错可以通过爬升过程绕过粒子。爬升在许多结构材料的长期耐久性或抗蠕变性能中起着至关重要的作用，特别是在载荷、温度和辐射的极端条件下。在这里，我们系统地研究位错-粒子相互作用机制。该分析基于三维离散位错动力学模拟，包括不可穿透粒子、弹性相互作用、位错自爬升、交叉滑移和滑动。基于微观结构演化的变分原理，模拟了核心扩散主导的位错自爬升过程，并采用自适应时间步进方案将位错滑动和交叉滑动耦合起来，以弥补时间尺度上的分离。粒子引起的应力场是基于粒子-矩阵不匹配实现的。该模型有助于理解基本的颗粒旁路机制，阐明位错滑动、攀爬和交叉滑移对蠕变的影响。
Plastic deformation in crystalline materials occurs through dislocation slip and strengthening is achieved with obstacles that hinder the motion of dislocations. At relatively low temperatures, dislocations bypass the particles by Orowan looping, particle shearing, cross-slip or a combination of these mechanisms. At elevated temperatures, atomic diffusivity becomes appreciable, so that dislocations can bypass the particles by climb processes. Climb plays a crucial role in the long-term durability or creep resistance of many structural materials, particularly under extreme conditions of load, temperature and radiation. Here we systematically examine dislocation-particle interaction mechanisms. The analysis is based on three-dimensional discrete dislocation dynamics simulations incorporating impenetrable particles, elastic interactions, dislocation self-climb, cross-slip and glide. The core diffusion dominated dislocation self-climb process is modelled based on a variational principle for the evolution of microstructures, and is coupled with dislocation glide and cross-slip by an adaptive time-stepping scheme to bridge the time scale separation. The stress field caused by particles is implemented based on the particle–matrix mismatch. This model is helpful for understanding the fundamental particle bypass mechanisms and clarifying the effects of dislocation glide, climb and cross-slip on creep deformation.
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影响因子：
3.2
作者：
Davoudi, Kamyar M.;Nicola, Lucia;Vlassak, Joost J.
通讯作者：
Vlassak, Joost J.
影响因子：
1.6
作者：
ASHBY, MF;JOHNSON, L
通讯作者：
JOHNSON, L
DOI：
10.1080/01418618508237562
发表时间：
1985-01-01
期刊：
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES
影响因子：
--
作者：
BARNETT, DM
通讯作者：
BARNETT, DM
影响因子：
9.8
作者：
Cui, Yinan;Po, Giacomo;Ghoniem, Nasr M.
通讯作者：
Ghoniem, Nasr M.
影响因子：
2.6
作者：
Ayas, C.;Dautzenberg, L. C. P.;Deshpande, V. S.
通讯作者：
Deshpande, V. S.