基于晶体塑性与内聚力模型的Cu-Ni-Si合金晶界起裂研究  

STUDY ON CRACK INITIATION AT GRAIN BOUNDARY OF Cu⁃Ni⁃Si ALLOY BASED ON CRYSTAL PLASTICITY AND COHESIVE ZONE MODEL

作　　者：陶蒙 于培师 赵军华 TAO Meng;YU PeiShi;ZHAO JunHua(Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology,School of Mechanical Engineering,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学机械工程学院江苏省食品先进制造装备技术重点实验室,无锡214122

出　　处：《机械强度》2024年第5期1184-1191,共8页Journal of Mechanical Strength

基　　金：国家自然科学基金项目(11972171);机械结构力学及控制国家重点实验室开放课题(MCMSE-0422G04)资助。

摘　　要：金属材料的宏观失效行为与其微结构的损伤演化密切相关。除了原位加载实验观察以外,利用先进的数值方法对其微结构的演化进行模拟预测,逐渐成为研究金属材料多尺度损伤演化机制的有效工具。目前对于多晶金属晶粒内部的位错运动可以利用晶体塑性有限元法进行准确模拟,但对于位错导致的损伤累积和微裂纹萌生模拟依然存在较大挑战。对于大多数金属多晶材料,位错通常在晶界处塞积导致应力集中,进而在晶界处开裂。因此,实现整个过程的模拟需要构建能够同时描述位错运动与晶界开裂的数值模型。针对此问题,将晶体塑性有限元与内聚力模型相结合,实现了材料微观变形-损伤的统一描述,并建立了描述位错运动与晶界开裂的整体有限元模型。随后,以多晶Cu-Ni-Si合金为研究对象,模拟了材料从变形、起裂、裂纹扩展到断裂的微结构演化过程,并揭示了局部沿晶断裂到整体失效的机制,阐明了晶粒取向对初始断裂位置与裂纹扩展的影响。该模型为各类金属材料失效行为的多尺度损伤演化模拟提供了可行的技术基础。The macroscopic failure behavior of metal materials is closely related to the damage evolution of microstructure.In addition to in⁃situ loading experiments,advanced numerical methods are used to simulate and predict the microstructure evolution of metal materials,which has gradually become an effective tool to study the multi⁃scale damage evolution mechanism of metal materials.At present,the dislocation motion inside polycrystalline metal grains can be simulated by crystal plastic finite element method,but there are still challenges in the simulation of damage accumulation and microcrack initiation caused by dislocation.For most metal polycrystalline materials,dislocations are usually plugged at grain boundaries leading to stress concentration and then cracking at grain boundaries.Therefore,the simulation of the whole process requires the construction of a numerical model that can describe both dislocation motion and grain boundary cracking.In order to solve this problem,combining the crystal plastic finite element model with the cohesive zone model to achieve a uniform description of material microscopic deformation and damage,and a global finite element model to describe dislocation motion and grain boundary cracking was established.Then,taking polycrystalline Cu⁃Ni⁃Si alloy as the research object,the microstructure evolution process from deformation,crack initiation,crack propagation to fracture was simulated,and the mechanism from local intergranular fracture to global failure was revealed,and the effect of grain orientation on initial fracture location and crack propagation was clarified.This model provides a feasible methodology for multi⁃scale damage evolution simulation of the failure behavior of various metal materials.

关 键 词：晶体塑性 内聚力 有限元模拟 多晶金属 变形断裂 

分 类 号：TB13[理学—物理] O34[理学—应用物理]