The paper reflects on the development of Nb-silicide based alloys vis-à-vis property goals and compares them with refractory-complex-concentrated-alloys (RCCAs) for their density, oxidation and mechanical properties. The Nb-silicide based alloys are separated in two groups, namely those with and without Ti addition. It is discussed how alloying has supressed pest oxidation and scale spallation in Nb-silicide based alloys. The processing of the latter and RCCAs is discussed, similarities are highlighted, and the significance of macrosegregation is stressed. The importance of alloying additions, Ti/Si ratio, solidification processing, growth rate in directional solidification, and thermomechanical processing for meeting the fracture toughness goal is highlighted. Discussion about the creep of Nb-silicide based alloys emphasises the role of microstructure type, the importance of the Ti/Si, Ti/Hf, Nb/(Ti + Hf) ratios and alloying additions. Nb-silicide based alloys and RCCAs have same phases in their microstructures, use essentially the same alloying additions, and their alloying behaviour is described by the parameters δ, Δχ, VEC, ΔH_mix, ΔS_mix and Ω. It is shown that RCCAs with Nb and other RM additions studied to-date can be represented together with Nb-silicide based alloys in the same maps of the aforementioned parameters. Methods of development, future directions of research and development are discussed.

本文根据性能目标反思了 Nb 硅化物基合金的发展，并将它们与难熔复合浓缩合金 (RCCA) 的密度、氧化和机械性能进行了比较。Nb-硅化物基合金分为两组，即添加和不添加 Ti 的合金。讨论了合金化如何抑制 Nb 硅化物基合金中的害虫氧化和氧化皮剥落。讨论了后者和 RCCA 的处理，强调了相似之处，并强调了宏观隔离的重要性。强调了合金添加、Ti/Si 比、凝固过程、定向凝固的生长速率和热机械加工对于满足断裂韧性目标的重要性。关于 Nb 硅化物基合金蠕变的讨论强调了微观结构类型的作用、Ti/Si、Ti/Hf、Nb/(Ti + Hf) 比率和合金添加量的重要性。Nb-硅化物基合金和 RCCAs 的微观结构具有相同的相，使用基本相同的合金添加剂，它们的合金化行为由参数 δ、Δχ、VEC、ΔH 描述_混合，ΔS_混合和Ω。结果表明，迄今为止研究的具有 Nb 和其他 RM 添加物的 RCCA 可以与 Nb 硅化物基合金一起表示在上述参数的相同图中。讨论了开发方法、未来的研究和开发方向。