SGER: A Study of a Ordered Body Centered Cubic Structure Superalloy Formed by Spinodal Decomposition

在这份SGER提案中，将研究一种新的四元合金(Fe30Ni20Mn25Al25)的科学有趣的特征，以确定这种特殊的合金系统是否可以用作结构材料。这种新合金是一种用于高温结构的镍基高温合金的BCC等价物。一个主要的目标是详细地研究调节分解的动力学和块体的相稳定性。原位高温电子显微镜将被用来表征相的粗化和稳定性。在透射电子显微镜下，将通过体应变实验和原位应变实验来表征变形行为。该合金将在铸态和不同的热处理后进行考虑，以确定在不牺牲高温强度的情况下具有足够延展性的最佳工艺条件。如果成功，这项工作的结果将适用于其他合金系统，因为调幅分解，其次是有序代表了一种新的处理微结构的方法。教育影响包括培养一名硕士研究生和两名本科生将参与该项目。他们将在材料表征技术和机械测试方面获得不同程度的技能。此外，计划与ORNL密切合作，材料将在国家实验室进行处理。

In this SGER proposal, scientifically interesting features of a new quaternary alloy (Fe30Ni20Mn25Al25) will be examined to determine whether this particular alloy system would be useful as a structural material. This new alloy is a bcc equivalent of a nickel-based superalloy that has been used for high temperature structures. A major objective is to investigate in detail the kinetics of both the spinodal decomposition and the phase stability in bulk. In-situ high temperature transmission electron microscopy will be used to characterize phase coarsening and stability. Deformation behaviors will be characterized using both bulk and in-situ straining experiments in transmission electron microscope. The alloy will be considered in both as-cast and following different heat treatments to determine the optimum process conditions for sufficient ductility without sacrificing high-temperature strength. If successful, results from this work will have applicability to other alloy system since the spinodal decomposition, followed by ordering represents a new way of manipulating microstructures.The educational impacts include training a M.S. student and two undergraduates who will work on the project. They will acquire varying degrees of skill in materials characterization techniques and mechanical testing. In addition, a close collaboration with ORNL is planned wherein the materials will be processed at the national laboratory.