发表机构
University of California, Davis; University of Tennessee, Knoxville（加州大学戴维斯分校; 田纳西大学诺克斯维尔分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文报道了一种可铸造的Nb基共晶高温合金NMC-1，通过均匀层状结构实现1300-1500°C下高强度、低密度和低成本，为超高温结构材料提供新设计范式。
AI 中文摘要
在1300°C以上运行、超越Ni基高温合金极限的难熔合金，必须平衡高温强度、热稳定性、低密度、低成本以及室温拉伸延展性，而现有难熔合金尚未实现这一组合。本文报道了一种可铸造的Nb基共晶高温合金Nb-10Mo-9.5C（原子百分比，NMC-1），其由Nb-Mo固溶体和Nb2C碳化物相的均匀层状结构组成。NMC-1在1300°C和1500°C下分别实现了约300 MPa和约200 MPa的0.2%屈服强度，为Nb基合金中报道的最高值之一，并具有显著的应变硬化、非零室温拉伸延展性，且在1400°C下经过100小时后未观察到显微组织粗化。其低密度（8.65 g/cc）和低成本（约85美元/千克）产生了远超商业Nb、Mo、Ta和W合金的比强度-成本优值指数，为超高温结构材料建立了新的设计范式。
英文摘要
Refractory alloys operating above 1300 °C, beyond the limit of Ni-based superalloys, must balance high-temperature strength, thermal stability, low density, low cost, and room-temperature tensile ductility, a combination that existing refractory alloys have yet to achieve. Here we report a castable Nb-based eutectic superalloy, Nb-10Mo-9.5C (at. %, NMC-1), comprising a uniform lamellar structure of Nb-Mo solid solution and Nb2C carbide phases. NMC-1 achieves 0.2% yield strengths of ~300 MPa and ~200 MPa at 1300 °C and 1500 °C, respectively, among the highest reported for Nb-based alloys, with pronounced strain hardening, non-zero room-temperature tensile ductility, and no observed microstructural coarsening after 100 h at 1400 °C. Its low density (8.65 g/cc) and cost (~$85/kg) yield a specific-strength-per-cost merit index that far surpasses commercial Nb, Mo, Ta, and W alloys, establishing a new design paradigm for ultrahigh-temperature structural materials.
