团聚颗粒对SiC/AZ91D复合材料裂纹萌生和扩展行为影响的研究  

Effects of Agglomeration Particles on Cracking Initiation and Propagation Behavior of SiC/AZ91D Composites

作　　者：梁超群 尧军平[1] 李怡然 李步炜 陈国鑫 Liang Chaoqun;Yao Junping;Li Yiran;Li Buwei;Chen Guoxin(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330000,China)

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330000

出　　处：《稀有金属材料与工程》2024年第6期1709-1717,共9页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52065046,51661024);江西省科技重点研发计划(20202BBEL53024)。

摘　　要：基于复合材料真实微观结构,在颗粒与基体界面引入内聚力单元,建立了4种不同颗粒团聚分布的有限元模型(均匀分布、三处团聚、两处团聚和一处团聚),研究了颗粒团聚对SiC/AZ91D复合材料裂纹萌生和扩展机制的影响。结果表明:当裂纹萌芽时,应力在基体中分布很不均匀,最大应力值出现在颗粒群尖角处,颗粒团聚程度越严重,裂纹萌生最大应力值越大;当裂纹扩展时,颗粒团聚程度越严重,基体内最大应力值越大,裂纹扩展程度越高;当裂纹完全断裂时,随着颗粒团聚程度的加剧,颗粒应力最大值逐渐增加,而基体应力最大值变化不大。颗粒团聚加速裂纹萌生扩展过程,颗粒应均匀分布于基体中。复合材料裂纹萌生扩展机制是由于SiC颗粒群边界和尖角处应力集中严重,导致基体损伤,萌生微裂纹,微裂纹沿着切应力最大方向扩展汇集成主裂纹。Based on the real microstructure of composite materials,four finite element models with different particle aggregation distributions(uniform distribution,three-clustering,two-clustering,and one-clustering)were established by introducing cohesive element units at the interface between particles and matrix to investigate the influence of particle aggregation on the crack initiation and propagation mechanisms of SiC/AZ91D composite materials.The results show that when the crack initiates,stress distribution in the matrix is highly uneven,with the maximum stress occurring at the corners of the particle group.The more severe the particle aggregation,the greater the maximum stress value during crack initiation.As the crack propagates,the greater the degree of particle aggregation,the higher the maximum stress value in the matrix and the greater the extent of crack propagation.When the crack completely fractures,the maximum stress value of the particles gradually increases with the aggravation of particle aggregation,while the maximum stress value of the matrix remains relatively constant.Particle aggregation accelerates the crack initiation and propagation,and particles are uniformly distributed in the matrix.The crack initiation and propagation mechanism of composite materials is that the severe stress concentration at the boundaries and corners of the SiC particle group causes damage to the matrix,initiates microcracks,and then propagates along the direction of maximum shear stress to form the main crack.

关 键 词：颗粒团聚 SiC/AZ91D 有限元模型 单轴压缩 裂纹萌生 裂纹扩展 

分 类 号：TB333[一般工业技术—材料科学与工程]