Dislocation Core Structure and Slip Transmission Across Interphase Boundaries in Intermetallic Compounds

本研究结合实验和理论方法来研究金属间化合物中滑移跨越相干相界的传输机制。对单晶钛铝化物TiAl和Ti3Al进行了生长和力学测试，并将结果与位错核心结构和位错与相界面相互作用的理论预测结果进行了比较。在进行位错计算的同时，对铝化物相之间的界面进行了计算机模拟。合金的显微组织通过扩散结合和/或扩散渗透的组合而变化。对这些金属间材料的断裂机制进行了评估。采用压缩试验、透射电子显微镜和原子力显微镜。这项研究推进了原子建模的前沿，用于模拟界面和理解具有重要技术意义的高温金属间合金的力学行为。

This research combines experimental and theoretical approaches to investigate mechanisms of slip transmission across coherent interphase boundaries in intermetallic compounds. Single crystal titanium aluminides, TiAl and Ti3Al, are grown, mechanically tested, and the results compared to theoretical predictions of dislocation core structures and the interaction of dislocations with interphase boundaries. Computer modeling of the interface between the aluminide phases is carried out in parallel with the dislocation calculations. The microstructures of the alloys are varied by combinations of diffusion bonding and/or diffusive infiltration. The fracture mechanisms in these intermetallic materials are assessed. Compression testing, transmission electron microscopy, and atomic force microscopy are employed. %%% This research advances the frontiers of atomistic modeling for simulating interfaces and understanding of mechanical behavior in high temperature intermetallic alloys of technological importance.