Grain boundaries are defects in metals and ceramics that often control failure mechanisms such as corrosion and cracking. However, a vast number of different grain boundary types are found in a given material specimen. By controlling the types of grain boundaries present in a material through a process called grain boundary engineering, dramatic enhancements in materials performance, including corrosion and cracking resistance, can be achieved. The aim of this project is to advance the field of grain boundary engineering by investigating the properties of different types of grain boundaries in order to determine which grain boundaries are most important in preventing or causing materials failure. To accomplish this, a variety of different types of grain boundaries are investigated using a computational method called the activation-relaxation technique. This method provides essential information regarding the kinetic properties of grain boundaries, which are inherently related to the mechanisms of material degradation and failure.
The research results produced in this work will advance the field of grain boundary engineering?telling materials designers what the most critical defects in a material structure are allows them to focus on removing those critical defects, thereby extending the lifetime of a variety of engineering materials. The toolbox for materials design at the microstructural level will thus be greatly augmented, with societal benefits in reducing materials failures, enhancing product reliability, and thereby reducing materials usage. The project also focuses on the training of Ph.D.-level experts and B.S.-level practitioners in the newest tools of microstructure design. Combined with significant exposure of the research to industrial concerns, these newly-trained students are poised to carry the research results into the field and effect their implementation in advanced materials technologies.
