Modelling of the influence of alloy composition on flow stress in high-strength nickel-based superalloys
Modelling of the influence of alloy composition on flow stress in high-strength nickel-based superalloys
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DOI：
10.1016/j.actamat.2014.04.075
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发表时间：
2014-08-15
期刊：
影响因子：
9.4
通讯作者：
Reed, R. C.
中科院分区：
文献类型：
--
作者：
Crudden, D. J.;Mottura, A.;Reed, R. C.
提出了镍基高温合金屈服强度随化学成分变化的模型。与硬化理论一致，合金强度被假定为与反相边界（APB）能量和强化γ '相的分数的平方根的乘积成比例。之间的关系建立的APB能量估计使用CALPHAD数据库和密度泛函理论的预测。Ti、Ta、Nb、Cr、W和Mo所起作用的定量估计表明，这些元素对APB能量有深远的影响。提出了一个程序，使强度估计从最初输入的化学成分单独。对新型多元合金作了预测。深入了解如何组合物可以被隔离，以实现最佳强化。然而，γ '沉淀物的尺寸和间距没有明确预测或考虑;未来的工作必须解决这个问题。
A model is proposed for the variation of the yield strength of nickel-based superalloys as a function of chemical composition. Consistent with hardening theory, alloy strength is assumed to be proportional to the product of the anti-phase boundary (APB) energy and the square root of the fraction of the strengthening gamma' phase. A relationship is established between the APB energy estimated using a CALPHAD database and predictions from density functional theory. Quantitative estimates of the role played by Ti, Ta, Nb, Cr, W and Mo suggest that these elements have a profound effect on APB energy. A procedure is proposed to enable the strength to be estimated from an initial input of the chemical composition alone. Predictions are made for new multicomponent alloys. Insight is provided into how composition may be isolated for optimal strengthening. However, the size and spacing of the gamma' precipitates is not explicitly predicted or considered; future work must address this.