Hierarchical microstructure and properties of ferritic alloys strengthened by two-phase intermetallic precipitates

两相金属间析出强化铁素体合金的分级组织与性能

• 批准号: 240602619
• 负责人: Professor Dr. Christian Liebscher
• 金额: --
• 依托单位: Department of Materials Science and Engineering
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/240602619?language=en
• 关键词: Hierarchical; microstructure; properties; ferritic; alloys

The proposed research focuses on the development of ferritic alloys strengthened through two-phase L21-Ni2TiAl / B2-NiAl intermetallic precipitates and the characterization of their microstructural evolution. The microstructure of two ferritic alloys with base elements Fe, Al, Ni and different Ti levels is characterized in the course of solution and aging heat treatment. Advanced transmission electron microscopy techniques such as HAADF-STEM, ALCHEMI and in-situ electron microscopy are used to determine phase decomposition pathways, the crystallographic configuration of the corresponding matrix and precipitate phases and precipitate-dislocation interactions. The main focus is to develop formation mechanisms from the atomic to the microscopic level that lead to the formation of two-phase L21-Ni2TiAl / B2-NiAl precipitates. The experimental observations are complemented by first-principles calculations, which are coupled with thermodynamic approaches to study interfacial properties. Additional insight on the phase stability is obtained by site-preference and electronic structure calculations of the intermetallic compounds.

重点研究了L21-Ni2TiAl/B2-NiAl两相金属间化合物强化铁素体合金的发展及其组织演变特征。研究了两种基元素为Fe、Al、Ni和不同钛含量的铁素体合金在固溶和时效热处理过程中的显微组织。利用先进的电子显微镜技术，如HAADF-STEM、ALCHEMI和原位电子显微镜，确定了相分解途径、相应基质和析出相的晶型以及析出-位错相互作用。重点研究了从原子到微观两相L21-Ni2TiAl/B2-NiAl析出相的形成机制。实验观测得到了第一性原理计算的补充，并结合热力学方法研究了界面性质。通过对金属间化合物的位置择优和电子结构的计算，获得了对相稳定性的更多见解。