Dr. Wai-Yim Ching who is a Distinguished Physics professor from University of Missouri has done extensive research on Ceramics and published many research papers in the Journal of American Ceramic Society. One of his recent research is on IGF (Intergranular Glassy Film model) and conducted a detailed quantum mechanical analysis of a realistic IGF model using large scale modeling published in the Journal of American Ceramic Society (2018;101:2763-2688) in collaboration with Japanese Scientists.) Through this study in an intergranular glassy film model of silicon nitride, he has discussed the association of IGF structure on the strength, fracture toughness, and interfacial bonding in relation to processing methods. He also discussed, its main applications in complex structural ceramics.
What is an Intergranular Glass Film (IGF)?
Polycrystalline structures composed of crystallites. Clockwise from top left
In a crystal structure, a grain boundary is the interface region r between two grains or crystallites. In certain Ceramics like Silicon Nitride, the grain boundary can have a thin glassy film of around 1-2nm thickness. This IGF film is characterized by its thickness and is independent of crystallites orientation, but is dependent on composition and thickness of the glassy region. Silicon Nitride is one of the most thermodynamically stable ceramics. The presence of a thin intergranular Glassy films (IGF) plays an important role in determining its physical properties like fracture, creep and oxidation, because IGF’s are resistant to crystallization.
Dr. Wai-Yim Ching in collaboration with his colleagues conducted a study on first principles of intergranular glassy film model of silicon nitride, and through his study, he has found that the presence of thin glassy layer originates from the flexibility of structure in ceramics and can be optimized by the formation of defective sites with effective interatomic bonding between IGF and bulk silicon nitride. With this detailed quantum mechanical analysis, he also discussed its potential applications of his advanced computational modeling method in materials research.