Optimizing the mechanical properties of variations of Al10Co25Cr8Fe15Ni36Ti6 compositionally complex alloy

“成分复杂的合金/高熵合金”Al10Co25Cr8Fe15Ni36Ti6及其与Hf、Zr、W、Mo、Y和B等微量元素的变化被认为是长期应用于汽轮机的良好候选者。经过优化的热处理后，它们的主要特征是由有序晶体结构的长方体析出物和无序结构的基质组成的两相组织。此外，还检测到了第三个阶段。根据微量元素的不同，它有不同的形状，即针状或椭圆形，并在很大程度上影响力学性能。室温和600-800°C左右的拉伸试验显示出优异的力学性能，可与商业镍基高温合金如Inconel 617或Fe-Ni基合金如合金800相媲美。有关力学性能的最佳微量元素是Hf。含Hf的合金现在应该进一步优化，例如，通过添加少量在组织和氧化领域表现出色的有趣的微量元素W和/或Zr。

"Compositionally complex alloy/high entropy alloy" Al10Co25Cr8Fe15Ni36Ti6 and its variations with trace elements Hf, Zr, W, Mo, Y and B have been found to be good candidates for a long-term application in turbines. After an optimized heat treatment they are characterized mainly by a two phase microstructure consisting of cuboid precipitates of ordered crystal structure and a matrix of disordered structure. Additionally, a third phase has been detected. Depending on the trace element it has different shapes, i.e. needles or ellipsoids, and influences the mechanical properties massively.Tensile tests at room temperature and around 600-800°C show excellent mechanical properties, comparable to commercial Ni-based superalloy such as Inconel 617 or Fe-Ni based alloys like Alloy 800. The best trace element concerning mechanical properties has been found to be Hf. The alloy with Hf shall now be optimized further, e.g. by adding small amounts of interesting trace elements W and/or Zr which excel in the domains of microstructure and oxidation.