发表机构
California Polytechnic State University; Merrimack College（加州州立理工大学; 梅里马克学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究将CALPHAD计算与随机森林主动学习相结合，系统探索了Ru稳定的Nb基BCC+B2难熔合金成分空间，建立了高温稳定性设计规则，并识别出晶格失配作为关键优化目标。
AI 中文摘要
具有韧性体心立方（BCC）基体并由有序B2析出相强化的难熔合金，为镍基高温合金的γ/γ'架构提供了高温类比。钌作为B2稳定剂特别具有吸引力，因为RuHf、RuZr和RuTi能够在远高于1300°C的温度下保持有序相。在本工作中，平衡CALPHAD计算与随机森林引导的主动学习相结合，以探索一个含Ru的十元素Nb基成分空间，该空间包含Nb、Ta、Mo、V、Ru、Ti、Zr、Hf、Al和Y，分辨率为1 at.%。在500种经CALPHAD评估的合金中，计算重现了Ru-B2设计空间所报道的主要趋势。RuHf和RuZr保持稳定直至固相线，RuTi通常表现出固溶处理窗口，含Al合金优先形成竞争的σ和A15相。BCC+B2相区的上限从5 at.% Ru时的中位数约1570°C增加到9-10 at.% Ru附近的约1980°C。在IV族添加元素中，Hf、Zr和Ti产生逐渐降低的两相稳定性。使用物理动机标准进行重新筛选，确定了100种满足高温BCC+B2稳定性、无液相、相纯度和适当第二相分数要求的合金，包括19种贫Ru成分和两种独立报道的HfRu-B2合金。这些结果为Ru稳定的双相难熔合金建立了实用的成分设计规则，并将相特定的BCC/B2晶格失配确定为未来设计周期的关键目标。
英文摘要
Refractory alloys with a ductile body-centered-cubic (BCC) matrix strengthened by ordered B2 precipitates offer a high-temperature analogue to the gamma/gamma-prime architecture of Ni-based superalloys. Ruthenium is particularly attractive as a B2 stabilizer because RuHf, RuZr, and RuTi can retain ordered phases well above 1300 C. In this work, equilibrium CALPHAD calculations were coupled with random-forest-guided active learning to explore a ten-element Nb-based, Ru-bearing composition space containing Nb, Ta, Mo, V, Ru, Ti, Zr, Hf, Al, and Y at 1 at.% resolution. Across 500 CALPHAD-evaluated alloys, the calculations reproduced the principal trends reported for the Ru-B2 design space. RuHf and RuZr remained stable to the solidus, RuTi commonly exhibited a solutionizing window, and Al-containing alloys preferentially formed competing sigma and A15 phases. The upper bound of the BCC+B2 field increased from a median of approximately 1570 C at 5 at.% Ru to approximately 1980 C near 9-10 at.% Ru. Among the group-IV additions, Hf, Zr, and Ti produced progressively lower two-phase stability. Re-screening using physically motivated criteria identified 100 alloys satisfying requirements for high-temperature BCC+B2 stability, absence of liquid, phase purity, and appropriate secondary-phase fraction, including 19 Ru-lean compositions and two independently reported HfRu-B2 alloys. The results establish practical compositional design rules for Ru-stabilized dual-phase refractory alloys and identify phase-specific BCC/B2 lattice misfit as a key target for future design cycles.
