Grain Growth in Metallic Thin Films: Microscopy of Microstructural Development

Presented by Matthew Patrick, a graduate student at Columbia University and 2024 participant of the ASM Student Speaking Symposium (S3). To learn more about this contest, please visit https://bit.ly/2WXL3WV



Full Presentation Title: Grain Growth in Metallic Thin Films: Microscopy of Microstructural Development


Grain growth is a key tool in designing materials' structures and influencing their properties. Coarsening, however, is a complex process controlled by a wide range of microstructural features, including grain size, neighbor correlations, and crystallographic considerations like anisotropic grain boundary properties. We present a novel experimental framework, exploiting simplified thin film microstructures to study grain growth in situ in the transmission electron microscope. Films are imaged during heating and periodically quenched for orientation data to be collected. By coupling image data with automated grain boundary detection, we make high throughput measurements of geometric and topological aspects of the microstructure over time, like grain size and spatial distributions of triple junctions. Orientation maps are then used to reconstruct grain boundary character distributions and orientation texture, allowing estimates of surface and grain boundary energy dissipation. These cross-cutting data offer complementary information, correlated in space, and offer insight into the process of coarsening.