CAREER: Interface Control and Three Dimension Mechanisms of Branch-Limited Eutectic Growth

Iowa State University, Ames IA

Investigators

Abstract

The project seeks to advance the fundamental understanding of microstructural transformation in materials with emphasis on eutectic solidification. Major objectives are to identify, characterize and quantify the complex three-dimensional mechanisms involved in local adjustment and self-optimization of irregular growth morphologies. The project will develop a more complete and general view of coupled growth phenomena. Several solidification techniques will be used to grow eutectic structures under various types of thermal and geometric constraints. State-of-the-art characterization techniques, including optical and electron microscopy, serial micromilling, diffraction-based methods and in-situ imaging will be utilized to investigate the 3-D adjustment mechanisms and their relationship to the relevant anisotropic interfacial properties. Computational methods will also be employed for the investigation of various specific morphological features such as interface curvature, missing orientations, faceting behavior, growth mode transitions, and triple-junction morphology. Technological importance of eutectic solidification provides a clear source of motivation for students, and the visually striking microstructures that typically evolve during eutectic solidification serve as graphic illustrations of transition dynamics, providing very effective teaching examples. The topic of eutectic solidification offers a wealth of rich problems involving multicomponent thermodynamics, solid-liquid and solid-solid interfacial phenomena, morphological stability, chemical and thermal diffusion, and nucleation phenomena. The educational efforts are designed to establish a set of standard practices that will facilitate integrated research and teaching with the involvement of education professionals, leaders of student organizations, and representatives from various community youth organizations. By involving youth organizations, such as the Boys & Girls Clubs of America, an effort will be made to engage the disadvantaged and underrepresented segments of our youth population.