论文标题
螺钉的驯服：BCC金属和合金中的位错芯
The Taming of the Screw: Dislocation Cores in BCC Metals and Alloys
论文作者
论文摘要
以身体为中心的立方（BCC）过渡金属在低温下往往是脆弱的，在加工方面构成了重大挑战，并且对损害耐受性的主要关注点。脆性在很大程度上取决于螺钉脱位芯。将近一个世纪后，其性质和控制仍然是一个难题。在这里，我们介绍了基于物理的材料索引\ {CHI}，即BCC和以面部中心地带结构之间的能量差，可以指导对核心特性的操纵。晶格摩擦和成核屏障具有\ {Chi}的接近线性缩放，当\ {Chi}降至BCC合金中的阈值以下时，核心从非分级变为退化。 \ {CHI}与溶质价电子浓度有关，可以通过第一原理计算来定量预测，为延展性和坚硬的BCC合金设计提供了强大的路径。
Body-centred cubic (BCC) transition metals tend to be brittle at low temperatures, posing significant challenges in processing and major concerns for damage tolerance. The brittleness is largely dictated by the screw dislocation core; the nature and control of which remain a puzzle after nearly a century. Here, we introduce a physics-based material index \{chi}, the energy difference between BCC and face-centred-cubic structures, that guides manipulation of core properties. The lattice friction and nucleation barrier have near-linear scaling with \{chi} and the core transforms from non-degenerate to degenerate when \{chi} drops below a threshold in BCC alloys. \{chi} is related to solute valence electron concentrations and can be quantitatively predicted by first-principles calculations, providing a robust path for design of ductile and tough BCC alloys.
