基于ICME研究Al_(2)Y相对镁合金局部变形和损伤的影响

Investigating the influence of Al_(2)Y phase on local deformation and damage of Mg alloys using ICME

近年来,集成计算材料工程(ICME)已成为设计新材料和制造工艺最强大的材料基因组工程(MGE)方法之一。采用基于位错密度的晶体塑性相场损伤模型定性和定量分析了Al_(2)Y相对镁基体局部应力、应变、位错密度、滑移系统以及损伤行为的影响。结果表明:镁合金在塑性变形过程中,损伤驱动力与晶粒基面滑移的施密特因子(SF)呈非常明显的线性关系,SF<3的晶粒,损伤驱动力较大,SF>3的晶粒,损伤驱动力较小。镁基体中损伤的起源和传播还取决于Al_(2)Y相的大小和位置。位于晶界处的Al_(2)Y相会引起较大的应力集中,导致损伤驱动力以倾斜的角度(约45°)传播;较小的和位于晶内的Al_(2)Y相的损伤驱动力较小,在变形过程中起到强化镁基体的作用。

In recent years,integrated computational materials engineering(ICME)has become one of the most powerful materials genome engineering(MGE)methods for designing new materials and manufacturing processes.A dislocation density-based damage model for the crystalline plastic phase field was used to qualitatively and quantitatively analyze the effects of Al_(2)Y on local stress,strain,dislocation density,slip system and damage behavior of magnesium matrix.The results show that there is a very obvious linear relationship between the damage driving force and the Schmidt factor(SF)of grain basal slip during plastic deformation of magnesium alloys.For grains with SF<3,the damage driving force is greater,while for grains with SF>3,the damage driving force is smaller.The origin and propagation of damage in the magnesium matrix also depend on the size and location of the Al_(2)Y phase.The Al_(2)Y phase located at the grain boundaries will cause significant stress concentration,leading to the propagation of damage driving force at an oblique angle(approximately 45°).The damage driving force of the smaller Al_(2)Y phase and the intercrystalline Al_(2)Y phase is relatively small,which plays a role in strengthening the magnesium matrix during the deformation process.Integrated computational materials engineering(ICME)has emerged to be one of the most powerful materials genome engineering(MGE)approaches in designing new materials and manufacturing processes in recent years.