Abstract In this work, we utilize atomistic simulations to calculate the generalized stacking fault energies (GSFEs), which are related to the dislocation glide process, on four types of slip planes – {110}, {112}, {123}, and {134} – in two refractory multi-principal element alloys (MPEAs): MoNbTi and NbTiZr. To serve as a reference material for MoNbTi, we develop, validate, and employ an A -atom interatomic potential, which is expected to represent the response of the nominal random solution. Our calculations show that, owing to the variation in local chemical composition within small finite nanometer sized planes, (i) the peak GSFE values vary significantly among parallel planes; (ii) within the same specific {110} plane, substantial differences in the GSFE curves along the two non-parallel " open=" 111 directions are observed; (iii) the {110} GSFE curves develop an asymmetry, such that the peak energy is not achieved at half the lattice periodicity length, (iv) the GSFE value after a shift equaling the lattice periodicity length is not recovered; and (v) on average, the peak GSFE values are close to the volume fraction average of the peak GSFEs of their constituents.

中文翻译：

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两种难熔多主元素合金广义堆垛层错能的原子计算

摘要 在这项工作中，我们利用原子模拟来计算与位错滑移过程相关的广义堆垛层错能 (GSFE)，在四种类型的滑移面 - {110}、{112}、{123} 和 { 134} – 在两种难熔多主元素合金 (MPEA) 中：MoNbTi 和 NbTiZr。为了作为 MoNbTi 的参考材料，我们开发、验证并采用了 A 原子的原子间势，该势有望代表标称随机解的响应。我们的计算表明，由于在小的有限纳米尺寸平面内局部化学成分的变化，（i）峰值 GSFE 值在平行平面之间变化显着；(ii) 在同一特定 {110} 平面内，观察到沿两个非平行“open=”111 方向的 GSFE 曲线存在显着差异；(iii) {110} GSFE 曲线发展出不对称性，使得在晶格周期长度的一半处未达到峰值能量，(iv) 与晶格周期长度相等的位移后的 GSFE 值未恢复；(v) 平均而言，峰值 GSFE 值接近于其成分峰值 GSFE 的体积分数平均值。