论文部分内容阅读
动态应变时效,即位错和溶质原子的动态交互作用,对合金材料的力学性质产生重要影响.本文基于蒙特卡罗方法,建立了“多位错-溶质原子”二维动力学模型,分别模拟了单位错-恒定应力率、多位错-无应力、多位错-恒定应力和多位错-恒定应力率四种条件下位错和溶质原子的演化过程.单位错-恒定应力率情况下,低应力率时位错被溶质原子钉扎而无法脱钉,高应力率时位错未被钉扎而一直运动,只有在适当应力率范围内,位错才呈现出反复的钉扎和脱钉;多位错-无应力时,溶质原子向正/负位错的下/上方偏聚;多位错-恒定应力时,位错运动受溶质原子钉扎的影响随应力增大而减小;多位错-恒定应力率时,集群化的钉扎和脱钉过程导致了位错总位移呈现阶梯状的演化.模拟结果表明:“位错-溶质原子”尺度上呈现了动态应变时效微观过程,与其理论描述相一致.
Dynamic strain aging, which is the dynamic interaction between dislocations and solute atoms, has an important influence on the mechanical properties of the alloy.In this paper, based on the Monte Carlo method, the “multi-dislocation-solute atom” two-dimensional kinetic model Simulated the evolution of dislocations and solute atoms under the conditions of unit error-constant stress rate, multi-dislocation-no stress, multi-dislocation-constant stress and multi-dislocation-constant stress rate. , Dislocations can not be detached by solute atoms when dislocations are pinched at low stress rate, dislocations are not pinned and always move at high stress rate, dislocation shows repeated pinning and detachment only in the range of appropriate stress rate Multi-Dislocations - When stress is not applied, solute atoms are segregated towards the bottom / top of positive / negative dislocations. Multi-dislocations - At constant stress, dislocation motions are reduced with increasing stress due to the effect of solute atom pinning ; The cluster dislocation and pinning process resulted in a step-like evolution of the total dislocation displacement at the multi-dislocation-constant stress rate. The simulation results show that the dynamic strain at the “dislocation-solute atom” scale Aging microscopic process, consistent with its theoretical description.