Ab initio informed yield criterion across body-centered cubic transition metals
Ab initio informed yield criterion across body-centered cubic transition metals
复制标题
体心立方过渡金属的从头算知产率标准
DOI：
10.1016/j.actamat.2022.118098
复制
发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
E. Clouet
中科院分区：
文献类型：
--
作者：
Baptiste Bienvenu;L. Dezerald;D. Rodney;E. Clouet
体心立方（bcc）金属的塑性在低温下是非典型的，这是由1/2螺旋位错的重要晶格摩擦引起< 111>的。在本文中，我们提出了一个屈服准则，可用于预测屈服应力和主动滑移系统在所有体心立方过渡金属的任何外加应力。该标准是完全参数化的从头计算的1/2< 111>螺旋位错滑移性能，并适用于在单轴加载的情况下，在低温下的拉伸和压缩实验进行比较。该标准描述了在不同金属中实验观察到的大多数不同的塑性行为，即屈服应力和主动滑移系统对加载轴方向的依赖性，以及拉伸/压缩不对称性。我们发现，塑性屈服一般发生在较低的应力在拉伸比在压缩，但对于某些金属，特别是铌，有很大的区域的赤平投影的压缩是容易的。
Plasticity of body-centered cubic (bcc) metals is atypical at low temperatures, caused by the important lattice friction of 1/2< 111> screw dislocations. In this paper, we present a yield criterion that can be used to predict yield stress and active slip systems in all bcc transition metals for any applied stress. The criterion is fully parametrized on ab initio calculations of 1/2< 111> screw dislocation glide properties, and is applied in the case of uniaxial loading to compare with tension and compression experiments at low temperature. The criterion describes most of the different plastic behaviors observed experimentally in different metals, ie the dependence of the yield stress and active slip system on the orientation of the loading axis, as well as the tension/compression asymmetry. We find that plastic yield generally occurs at lower stresses in tension than in compression but for some metals, in particular niobium, there are large regions of the stereographic projection where compression is easier.