Numerical simulation of intergranular and transgranular crack propagation in ferroelectric polycrystals
Numerical simulation of intergranular and transgranular crack propagation in ferroelectric polycrystals
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DOI：
10.1007/s10704-011-9664-0
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发表时间：
2012-03-01
影响因子：
2.5
通讯作者：
Arias, Irene
中科院分区：
文献类型：
--
作者：
Abdollahi, Amir;Arias, Irene
本文提出了一个相场模型来模拟铁电多晶体中沿晶和穿晶裂纹的扩展。所提出的模型耦合三个相场描述（1）多晶结构，（2）裂纹的位置，和（3）铁电畴微结构。不同的多晶微观结构，获得从计算机模拟晶粒生长。然后，在铁电单晶断裂相场模型扩展到多晶体，将不同的断裂韧性的散装和晶界，和不同的晶体取向的晶粒。我们的模拟结果表明，沿晶裂纹扩展细晶粒显微组织中，而穿晶裂纹扩展中观察到的粗晶粒。裂纹偏转是细晶组织的主要增韧机制。由于铁电畴转换机制，显着的断裂韧性增强也得到了穿晶裂纹扩展。这些观察结果与实验一致。
We present a phase-field model to simulate intergranular and transgranular crack propagation in ferroelectric polycrystals. The proposed model couples three phase-fields describing (1) the polycrystalline structure, (2) the location of the cracks, and (3) the ferroelectric domain microstructure. Different polycrystalline microstructures are obtained from computer simulations of grain growth. Then, a phase-field model for fracture in ferroelectric single-crystals is extended to polycrystals by incorporating the differential fracture toughness of the bulk and the grain boundaries, and the different crystal orientations of the grains. Our simulation results show intergranular crack propagation in fine-grain microstructures, while transgranular crack propagation is observed in coarse grains. Crack deflection is shown as the main toughening mechanism in the fine-grain structure. Due to the ferroelectric domain switching mechanism, noticeable fracture toughness enhancement is also obtained for transgranular crack propagation. These observations agree with experiment.