李晓伟, 黄佩珍. 多场诱发表面和晶界扩散下沿晶微裂纹的演化[J]. 工程力学, 2015, 32(11): 27-32. DOI: 10.6052/j.issn.1000-4750.2014.04.0320
引用本文: 李晓伟, 黄佩珍. 多场诱发表面和晶界扩散下沿晶微裂纹的演化[J]. 工程力学, 2015, 32(11): 27-32. DOI: 10.6052/j.issn.1000-4750.2014.04.0320
LI Xiao-wei, HUANG Pei-zhen. THE EVOLUTION OF INTERGRANULAR MICROCRACKS DUE TO SURFACE AND GRAIN-BOUNDARY DIFFUSION INDUCED BY MULTI-FIELD[J]. Engineering Mechanics, 2015, 32(11): 27-32. DOI: 10.6052/j.issn.1000-4750.2014.04.0320
Citation: LI Xiao-wei, HUANG Pei-zhen. THE EVOLUTION OF INTERGRANULAR MICROCRACKS DUE TO SURFACE AND GRAIN-BOUNDARY DIFFUSION INDUCED BY MULTI-FIELD[J]. Engineering Mechanics, 2015, 32(11): 27-32. DOI: 10.6052/j.issn.1000-4750.2014.04.0320

多场诱发表面和晶界扩散下沿晶微裂纹的演化

THE EVOLUTION OF INTERGRANULAR MICROCRACKS DUE TO SURFACE AND GRAIN-BOUNDARY DIFFUSION INDUCED BY MULTI-FIELD

  • 摘要: 基于表面扩散和晶界扩散的经典理论及其弱解描述,对应力迁移、电迁移诱发表面扩散和晶界扩散下金属材料内部沿晶微裂纹的演化进行了有限元分析。详细讨论了扩散系数之比f、应力场Λ、电场χ 和形态比β 对沿晶微裂纹演化的影响。结果表明:多场下的沿晶微裂纹存在分节与不分节两种演化分叉趋势。fχ 有助于沿晶 微裂纹扩展,而Λ阻碍沿晶微裂纹扩展。裂腔分节时间随着Λ的增大而逐渐减小,而随着β 的增大而增大。当时,随着χ 的增大,裂纹分节的时间显著减小,即χ 加速裂纹分节;当时,χ 对裂纹分节时间的影响不 明显。

     

    Abstract: Based on the classical theory of surface diffusion and grain-boundary diffusion and its weak statement, a finite element program is developed to simulate the evolution of intergranular microcracks in metal materials due to the stress and electromigration-induced surface and grain-boundary diffusion. The effects of the ratio of grain-boundary diffusion to surface diffusion, the magnitude of the stress, the electric field and the aspect ratio on the evolution of intergranular microcracks are investigated in detail. The results show that the intergranular microcrack can split into two little microcracks or can propagate. The increase of the ratio of grain-boundary diffusion to surface diffusion and the magnitude of the electric field promote crack propagation, while the magnitude of the stress impedes crack propagation. The splitting time of the microcrack decreases with the magnitude of the stress increasing, while it increases with the aspect-ratio increasing. When , the splitting time decreases obviously with the increase of the electric field, that is, the electric field accelerates the microcrack splitting. However, the effect of the electric field is not obvious on the splitting time when .

     

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