论文标题
设计热力学稳定且本质上延性的耐耐磨合金
Designing a thermodynamically stable and intrinsically ductile refractory alloy
论文作者
论文摘要
开发延性难治性BCC合金仍然是一个挑战。合金的固有延展性（d）是表面能（$γ_s$）和不稳定的堆叠断层能（$γ_{USFE} $）的比率。降低价电子浓度已被证明可以改善难治合金的固有延展性。但是，与文献中建议的低价值标准相反，RE已被广泛用于污染W。在这里，我们使用密度功能理论来计算IV，V，VI元素的$γ_{USFE} $ $γ_{USFE} $的焓及其在BCC晶体结构中的25个equiatomic二元合金。我们发现，与组成平均值相比，正焓可导致$γ_{USFE} $的大幅度降低，从而改善了内在延展性。焓最大，在均衡浓度下，表明合金成分与比反之亦然之间的高度排斥相互作用。我们发现合金成分之间的排斥相互作用导致$γ_{USFE} $的减少，使合金本质上是延性的。
Developing ductile refractory BCC alloys has remained a challenge. The intrinsic ductility (D) of an alloy is the ratio of surface energy ($γ_s$) and unstable stacking fault energy ($γ_{usfe}$). Lowering the valence electron concentration has been shown to improve the intrinsic ductility of refractory alloys. However, Re has been widely used to ductilize W, contrary to the low valency criteria suggested in the literature. Here we use density functional theory to calculate the enthalpy of formation, $γ_{usfe}$ and $γ_s$ of Group IV, V, VI elements and their 25 equiatomic binary alloys in BCC crystal structure. We found that positive enthalpy leads to a considerable reduction in $γ_{usfe}$ compared to composition averaged value, resulting in improved intrinsic ductility. Enthalpy is maximum at the equiatomic concentrations indicating the highly repulsive interaction between the alloy constituents and vicer-versa. We found that the repulsive interaction between the alloy constituents leads to a reduction in $γ_{usfe}$, making alloys intrinsically ductile.
