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.

拟议的研究重点是通过两相L21-NI2TIAL / B2-NIAL金属间沉淀和其微结构演化的表征来增强铁质合金的发展。具有碱基元素Fe，Al，Ni和不同Ti水平的两种铁素能合金的微观结构在溶液和衰老热处理过程中的特征是表征的。先进的透射电子显微镜技术，例如HAADF-STEM，炼金术和原位电子显微镜，用于确定相位分解途径，相应矩阵的晶体结构和沉淀相的晶体构型以及沉淀脱位相互作用。主要重点是从原子能到显微镜水平开发形成机制，从而导致形成两相L21-NI2TIAL / B2-NIAL沉淀物。实验观察结果与第一原理计算相辅相成，这些计算与热力学方法相结合。对相位稳定性的额外见解是通过基本化合物的场地优先考虑和电子结构计算获得的。