Matteo Seita
Dept. of Materials Science & Engineering
Massachusetts Institute of Technology

Improving materials reliability by defect engineering

Location: EB1 Room 1011

Friday, October 30th 2015 - 11:00 am

Defects in materials are often seen as "weak points" - the ultimate causes of failure. However, certain defects, such as specific types of grain boundaries, can actually lead to improved materials reliability. Focusing on grain boundaries, I will discuss two examples of defect engineering that lead to greater failure resistance and predictability, both in electronic and structural materials. In the first example, a high-precision grain boundary engineering technique enables the synthesis of metal interconnects with improved resistance to electromigration. This results from the ability to tailor the microstructure to predominantly incorporate a single-type of grain boundary. In the second, the grain boundary susceptibility to hydrogen embrittlement in a high-strength alloy is quantified through the statistical analysis of fracture. The results capture a nuanced and unexpected relationship between grain boundary type and fracture, opening the paths to higher-fidelity failure predictions. These two examples inspire the definition of a broader materials design strategy based on defect engineering, which relies both on the correct identification of defect structure-property relationships and on the precise control over the defect population in the microstructure.

North Carolina State University