The Role of Interfacial Structure in the Evolution of Precipitate Morphology

本研究探讨了控制金属合金中析出相形态的基本机制。作为相间边界取向函数的生长边缘成核动力学的测量提供了必要的信息，以统一目前两种关于沉淀形态发展的理论：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，它从所涉及的相的晶体学预测沉淀取向关系、生长方向和习惯面。对镍铬合金生长过程中析出相/基体边界处错配位错结构的实验观察提供了部分共格边界在固体中迁移机制的信息。这项研究的长期好处是了解了导致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. ***