标题： 中心偏离的置换固溶体原子增强固溶强化在α-Ti中 显示英文标题

标题： Enhanced solid solution hardening by off-center substitutional solute atoms in α-Ti

摘要： 最近，{\alpha }-Ti中的一些替代溶质原子被预测会占据出乎意料的低对称性（LS）位置，远离高对称性（HS）晶格位点，这被认为会导致增强的固溶强化（SSH）。 在本工作中，在连续弹性理论框架内评估了由LS偏心溶质原子引起的SSH，与由其HS晶格位点对应的SSH进行比较。 通过弹性偶极子模型计算了{\alpha }-Ti固溶体中溶质原子与基面/棱柱面边缘/螺型<a>位错之间的相互作用能和力，并利用该模型评估了溶质原子引起的强度增量。 我们表明，一般来说，LS溶质原子与位错的相互作用比其HS对应物要强得多。 计算得到的相互作用能表明，LS溶质原子在基面<a>位错的滑移面之上/之下形成氛围，但无论位错类型（边缘或螺型），在棱柱面<a>位错的滑移面上则没有形成氛围。 大多数LS溶质原子引起的强度增量比其HS对应物高出一个数量级以上。 由LS溶质原子引起的SSH效应主要由溶质原子d轨道的Jahn-Teller分裂强度决定，这与由HS溶质原子引起的SSH效应不同，后者主要由原子尺寸不匹配主导。 显示英文摘要

摘要： Most recently, some substitutional solute atoms in {\alpha}-Ti have been predicted to occupy unexpectedly the low-symmetry (LS) positions away from the high-symmetry (HS) lattice site, which was speculated to result in enhanced solid solution hardening (SSH). In the present work, the SSH induced by the LS off-center solute atom is evaluated within the framework of continuum elasticity theory, in comparison with that induced by its HS lattice-site counterpart. The interaction energy and force between the solute atom and the basal/prismatic edge/screw <a> dislocations in {\alpha}-Ti solid solution are calculated with the elastic dipole model, with which the strength increments induced by the solute atoms are evaluated with the Labusch model. We show that, in general, the LS solute atom interacts much more strongly with the dislocations than its HS counterpart does. The calculated interaction energies suggest that the LS solute atom forms atmosphere above/below the slip plane of the basal <a> dislocations but on the slip plane of the prismatic <a> dislocations regardless of the dislocation types (edge or screw). The strength increments caused by most of the LS solute atoms are more than an order of magnitude higher than those by their HS counterparts. The SSH effect induced by the LS solute atom is mainly determined by the strength of the Jahn-Teller splitting of the d-orbitals of the solute atom, dissimilar to that induced by HS solute atom where the atomic size mismatch dominates.