The Role of Interfacial Structure in the Evolution of Precipitate Morphology

小行星9303518 本研究探讨了金属合金中沉淀形态的基本机制。 作为相间边界取向的函数的生长台阶成核动力学的测量提供了必要的信息，以统一用于沉淀物形态发展的两种当前理论：沉淀形态的一般理论，它将沉淀形状与边界迁移率联系起来，不变线理论，它预测沉淀取向关系，生长方向，以及所涉及的相的结晶学中的惯习面。 在镍铬合金生长过程中，在沉淀物/基体边界处的失配位错结构的实验观察提供了关于部分相干边界在固体中迁移的机制的信息。 该研究的长期利益是了解微观结构演变的物理过程，这将指导商业金属合金的改进。 ***

9303518 Reynolds This research examines the fundamental mechanisms governing precipitate morphology in metal alloys. The measurement of growth ledge nucleation kinetics as a function of interphase boundary orientation provides necessary information to unify two current theories for the development of precipitate morphology: the general theory for precipitate morphology, which relates precipitate shape to boundary mobilities, and the invariant line theory, which predicts precipitate orientation relationships, growth directions, and habit planes from the crystallography of the phases involved. Experimental observation of the misfit dislocation structures at precipitate/matrix boundaries during growth in a nickel-chromium alloy provides information on mechanisms by which partially coherent boundaries migrate in solids. %%% The long term benefit of the research is understanding of the physical processes responsible for microstructural evolution, which guides improvement in commercial metal alloys. ***