Effects of configuration parameters on the deformation and fracture behaviors of TiB2/Cu composites with network structure: A numerical approach using an enhanced finite element model
Effects of configuration parameters on the deformation and fracture behaviors of TiB2/Cu composites with network structure: A numerical approach using an enhanced finite element model
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DOI：
10.1016/j.commatsci.2022.111212
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发表时间：
2022-02-01
影响因子：
3.3
通讯作者：
Liang, Shuhua
中科院分区：
文献类型：
--
作者：
Liu, Nan;Zhang, Qiangqiang;Liang, Shuhua
为了反映硬质相TiB_2被软相铜包裹的真实网络复合材料，本文提出了一种更接近真实晶胞结构的大晶胞模型。以实际扫描电子显微镜为基础，提取了TiB2/Cu复合材料的微观几何特征，并采用随机合成算法对网络结构进行重构。基于MatLab，利用Voronoi算法建立了TiB2/Cu复合材料的三维网络模型。采用有限元方法研究了TiB_2颗粒壁厚、基体相尺寸和基体相形态等结构参数对网络状TiB_2/Cu复合材料变形和断裂行为的影响，并预测了复合材料的力学性能。该模型引入了颗粒壁脆性断裂、基质延性破坏和界面牵引力分离三种破坏模式。为了验证模拟结果，给出了实验应力-应变曲线。结果表明，两者趋势吻合较好，仿真结果稳定可靠。用屈服强度、弹性模量、伸长率和拉伸强度来评价网络复合材料的综合力学性能。定量地给出了颗粒壁的等效应力和应力集中系数、网络的脆性断裂过程、界面脱粘、裂纹损伤和基质的等效塑性应变。结果表明，网络状TiB_2/Cu复合材料的承载能力由铜基体、TiB_2颗粒壁和界面决定。建立了网络结构复合材料的宏观和微观结构-性能关系。该工作为实验中网络复合材料的构型设计提供了参考和指导。
In order to reflect the real network composites with a hard phase TiB2 surrounded by a soft phase Cu, a developed large crystal-like cell model which closer to the real cell structure is proposed in this paper. Micro-geometric features of network TiB2/Cu composites are extracted based on the actual SEM, and a stochastic synthesis algorithm is adopted to reconstruct network structure. Based on MATLAB, a 3D network model of TiB2/Cu composites is established through Voronoi algorithm. By using finite element method, the effects of configuration parameters including TiB2 particle wall thicknesses, matrix phase sizes and matrix phase morphology on the deformation and fracture behaviors in network TiB2/Cu composites are investigated, and the mechanical properties of the composites are predicted. Three failure modes including brittle fracture of particle wall, ductile damage of matrix and traction-separation law of interface are introduced in the proposed models. The experimental stress-strain curves were implemented to verify the simulation results. The results show that the trend is in good agreement and the simulation results are stable and reliable. The comprehensive mechanical properties of network composites are assessed by yield strength, elastic modulus, elongation and tensile strength. The equivalent stress and stress concentration factor of the particle wall, brittle fracture process of network, interfacial debonding, crack damage and equivalent plastic strain of matrix are quantitatively presented. It is illustrated that the bearing capacity of network TiB2/Cu composites is determined by Cu matrix, TiB2 particle wall and interface. A macro and micro structure-properties relationship of network configuration composites is established in this paper. This work provided reference and guidance for the configuration design of the network composites in the experiment.