随机晶界分布和连通性对晶间破坏行为的影响

THE IMPACT OF RANDOM GRAIN BOUNDARY DISTRIBUTION AND CONNECTIVITY ON INTERGRANULAR FRACTURE OF POLYCRYSTALLINE MATERIALS

采用随机有限元方法研究了两个具有相同不均匀材料属性和相同随机晶界含量但不同随机晶界分布的特殊多晶体样本在准静态拉伸下的晶间破坏行为,发现随机晶界连通性强的样本的断裂能比较低.在不同随机晶界含量下分别构造的50个晶界随机分布的样本的计算结果表明,断裂能与平均晶界连通数的关联并不明显,甚至还出现了相反的结果,即在相同随机晶界含量下,平均晶界连通数大的计算样本的断裂能反而大.

A 2-D stochastic finite element method (SFEM) is used to investigate the intergranular failure behavior of two specific samples with same heterogeneous material distribution and same fraction of random boundaries while their configuration of random boundaries are different. It is found that the sample with low random grain boundary connectivity has low fracture energy. However, the statistic results of groups with different fraction of random grain boundaries (each group contains fifty samples) show that the relationship between fracture energy and average random grain boundary correlation number is uncertain. Some contrary results also appear, i.e., with the same fraction of random grain boundaries, some samples with larger grain boundary correlation length show higher fracture energy.