Diffraction Microscopy Predicts Material Microstructure

Researchers have discovered new information that will aid materials scientists in predicting how material properties change due to stresses such as high temperatures. The current model for forecasting a material’s structure and properties does not apply to polycrystalline materials. So, they developed a new model using near-field high energy diffraction microscopy (HEDM).

Most metals, alloys, and ceramics used in industrial and consumer equipment and goods appear consistently solid to the naked eye. However, they are polycrystalline at the microscopic level, consisting of aggregates of grains of various sizes, shapes, and crystal orientations. When subjected to stresses, a network of grain boundaries binds the grains together, affecting the material’s characteristics.

While making new material, scientists need to control its microstructure, including its grain boundaries. Scientists manipulate the density of grain boundaries to meet different material needs. For the last seventy years, researchers have used a theory that predicts materials’ behavior. It says that the speed at which grain boundaries move throughout a heated material depends on the boundary’s shape. The researchers have shown that this theory, formulated to describe the ideal case, does not apply in real polycrystals.

Using high-energy diffraction microscopy and related techniques, researchers can view hundreds of crystals and estimate their orientations in opaque metals and ceramics. The procedure necessitates high-energy X-rays, which are only available at a few synchrotron sources throughout the world.

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