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.

晶体材料中的塑性变形通过位错滑移发生，并且通过阻碍位错运动的障碍物来实现强化。在相对较低的温度下，位错通过 Orowan 循环、粒子剪切、交叉滑移或这些机制的组合绕过粒子。在升高的温度下，原子扩散性变得明显，因此位错可以通过爬升过程绕过粒子。Climb 在许多结构材料的长期耐久性或抗蠕变性中起着至关重要的作用，尤其是在负载、温度和辐射的极端条件下。在这里，我们系统地研究了位错 - 粒子相互作用机制。该分析基于三维离散位错动力学模拟，包括不可穿透的粒子、弹性相互作用、错位自爬、横滑和滑行。核心扩散主导的位错自爬升过程基于微结构演化的变分原理建模，并通过自适应时间步长方案与位错滑移和交叉滑移耦合，以弥合时间尺度分离。由粒子引起的应力场是基于粒子-基体失配实现的。该模型有助于理解基本的粒子旁路机制，并有助于阐明位错滑移、爬升和横向滑移对蠕变变形的影响。并通过自适应时间步长方案与位错滑移和横滑相结合，以弥合时间尺度分离。由粒子引起的应力场是基于粒子-基体失配实现的。该模型有助于理解基本的粒子旁路机制，并有助于阐明位错滑移、爬升和横向滑移对蠕变变形的影响。并通过自适应时间步长方案与位错滑移和横滑相结合，以弥合时间尺度分离。由粒子引起的应力场是基于粒子-基体失配实现的。该模型有助于理解基本的粒子旁路机制，并有助于阐明位错滑移、爬升和横向滑移对蠕变变形的影响。