Potential of Co-base Superalloys: Hierarchical Microstructures and Nanomechanical Properties of Co3(Al,W)

钴基高温合金的潜力：Co3(Al,W)的分级微观结构和纳米力学性能

• 批准号: 317532718
• 负责人: Dr.-Ing. Florian Vogel
• 金额: --
• 依托单位: Institut für Angewandte Materialforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/317532718?language=en
• 关键词: Potential; Co; base; Superalloys; Hierarchical

Due to the recent discovery of a stable microstructure analogous to that of Ni-bases superalloys, Co-based superalloys holds the potential to be a next generation material class for high temperature applications. To advance and optimize these materials, understanding how to improve the microstructural stability is required. In ternary Co-Al-W superalloys, the addition of 8 at.% Cr alters the partitioning of the alloying elements, resulting in the formation of further particles inside the cube shaped precipitates. It has been reported that mechanical properties can be improved by the formation of such hierarchical structures. The proposed work aims at gaining a better understanding of the formation and evolution of hierarchical microstructures and their impact on the mechanical properties for the purpose of elucidating methods of Co-based superalloy design. The nanomechanical properties of isolated cube shaped precipitates with additional inclusive particles insides will be studied to determine their impact. This will be done using a nanoindenter to deform single, isolated cube shaped precipitates with and without the inclusive particles. Additionally, the microstructural evolution of both ternary Co82Al9W9 and quaternary Co74Al9W9Cr8 will be characterized. This will be achieved by utilizing transmission electron microscopy with a lateral resolution on the nanometer scale in conjunction with atom probe tomography to visualize the atomic clustering of the inclusive particles. This complementary approach allows for the clarification of the thermodynamic driving forces and, consequently, the stability of the phases.

由于最近发现了一种类似于镍基高温合金的稳定微观结构，钴基高温合金具有成为下一代高温应用材料的潜力。为了推进和优化这些材料，需要了解如何提高微观结构的稳定性。在Co-Al-W三元高温合金中，添加8at。% Cr改变了合金元素的分配，导致在立方体析出物内部形成进一步的颗粒。据报道，通过形成这种分层结构可以改善机械性能。本研究旨在更好地了解分层微观组织的形成和演变及其对力学性能的影响，从而阐明co基高温合金的设计方法。将研究带有附加包涵颗粒的孤立立方体析出物的纳米力学性能，以确定它们的影响。这将使用纳米压头来变形单个，孤立的立方体形状的沉淀，有或没有包含颗粒。此外，还对三元Co82Al9W9和四元Co74Al9W9Cr8的显微组织演变进行了表征。这将通过利用具有纳米级横向分辨率的透射电子显微镜与原子探针断层扫描相结合来实现，以可视化包含颗粒的原子簇。这种互补的方法允许澄清热力学驱动力，因此，相的稳定性。