Abstract Using both novel high-throughput screening via combinatorial thin film deposition and conventional bulk alloy synthesis techniques, a large region of the AlCrFeNiTi composition space has been probed for alloys that could serve as low cost alternatives to nickel-base superalloys for medium-to-high temperature structural applications. Phase formation trends in this highly complex alloying system have been determined using characterisation techniques that span multiple length scales—from bulk X-ray diffraction and differential scanning calorimetry to atomically resolved scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. A large region of stability for both disordered A2 and ordered B2/L21 type phases is observed, with several compositions exhibiting fine-scaled precipitation structures of these two phases. For alloys with ≥20 at.% Al, the precipitation structure was further refined to a nano-scale lamellar arrangement of A2 and B2/L21 phases. Formation of C14 Laves phase, especially for compositions with > 10 at.% Ti, has consistently been observed. We include a screening of the mechanical properties based on nanoindentation and macroscopic hardness test data correlated with scanning electron microscope (SEM) observations of the hardness indents. The phase formation trends observed by both combinatorial thin film deposition and bulk alloy synthesis are discussed in detail for samples in the as-deposited and as-cast conditions, respectively.

中文翻译：

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B2/L21沉淀强化AlCrFeNiTi成分复杂合金的组合探索

摘要 使用通过组合薄膜沉积的新型高通量筛选和传统的大块合金合成技术，已经探索了大面积的 AlCrFeNiTi 成分空间的合金，这些合金可以作为镍基高温合金的低成本替代品，用于中到高温结构应用。这种高度复杂的合金系统中的相形成趋势已经使用跨越多个长度尺度的表征技术来确定——从体相 X 射线衍射和差示扫描量热法到原子分辨扫描透射电子显微镜和能量色散 X 射线光谱。观察到无序 A2 和有序 B2/L21 型相的大范围稳定性，其中几种组合物表现出这两个相的精细沉淀结构。对于含 ≥ 20 at.% Al 的合金，析出结构进一步细化为 A2 和 B2/L21 相的纳米级层状排列。一直观察到 C14 Laves 相的形成，特别是对于含有 > 10 at.% Ti 的组合物。我们包括基于纳米压痕和与硬度压痕的扫描电子显微镜 (SEM) 观察相关的宏观硬度测试数据的机械性能筛选。分别针对沉积态和铸态条件下的样品详细讨论了通过组合薄膜沉积和块状合金合成观察到的相形成趋势。% Ti，一直被观察到。我们包括基于纳米压痕和与硬度压痕的扫描电子显微镜 (SEM) 观察相关的宏观硬度测试数据的机械性能筛选。分别针对沉积态和铸态条件下的样品详细讨论了通过组合薄膜沉积和块状合金合成观察到的相形成趋势。% Ti，一直被观察到。我们包括基于纳米压痕和与硬度压痕的扫描电子显微镜 (SEM) 观察相关的宏观硬度测试数据的机械性能筛选。分别针对沉积态和铸态条件下的样品详细讨论了通过组合薄膜沉积和块状合金合成观察到的相形成趋势。