Jessica Krogstad and Robert Maass, both assistant professors of materials science and engineering, recently received National Science Foundation (NSF) CAREER awards for their submitted proposals.
The NSF’s Early Career Development Program’s CAREER awards are prestigious, competitive awards given to young faculty who exemplify the role of teacher-scholar through outstanding research, excellent education, and the integration of education and research. The program will provide five years of support for each award.
Krogstad’s CAREER award was for her proposal “Enhanced Ferroelastic Toughening in Electroceramic Composites through Microstructural Coupling.” Specific bonding configurations in ceramic materials enable unique functionalities in a wide range of advanced applications, from supercomputers to automotive exhaust sensors to smart phones. However, these same atomic bonds that can do so many wonderful things are also prone to becoming brittle and breaking easily.
“It’s an engineer’s job to take those intrinsic properties and enhance them at the microstructure — without changing the electrical properties,” Krogstad said.
By coupling new insights with processing science, Krogstad will be able to accelerate the development of new electroceramic materials and materials systems that will drastically expand the existing limits of performance and durability.
“Receiving this award is tremendous, both in terms of the visibility my research lab has received as well as the long-term commitment that will allow us to pursue high-risk, cross-cutting experiments on toughening mechanisms in functional ceramic materials,” Krogstad said. “This award is for young investigators with great, crazy ideas that will be gamechangers… and I’m honored to have received it.”
In addition to the research that will be done, some of the award will also support Girls Learning About Materials (GLAM) Camp that Krogstad helps to lead. This camp is one of the summer programs Women in Engineering (WIE) offers for high school girls interested in materials science.
Maass’ CAREER award was for his proposal “Spatiotemporal Avalanche Kinetics in Size-Dependent Crystal Plasticity.” According to Maass, when a metallic component is stressed to the extent that it plastically deforms, many defects operate to allow the permanent shape to change. In crystalline metals (of which most metals used for technical applications are a part) these defects are called dislocations. Acting cooperatively, many dislocations can begin to move at the same time. This process can lead to abrupt plastic instabilities that deteriorate the structural stability of components and eventually trigger failure. One main problem with such collective, avalanche-like processes is that they occur spontaneously, which means that they are hard to predict. In addition, these dislocation avalanches are confined to the nanometer scale and proceed extremely fast. As a result, very little is known currently about how they proceed in space and time.
“There has been a paradigm shift in crystal plasticity in the past 10 years,” Maass said. “We used to focus on plasticity by looking at flow descriptions based on mean properties… but we’re finding there are mechanisms that have scale-free behavior, with no mean — we will trace defect rearrangements in real time, which is a really cool thing to see.”
According to Maass, his research will unravel the precise dynamics of dislocation avalanches, tracking not only their spatiotemporal dynamics (belonging to both space and time), but also defining how they respond to changes in temperature. This will be done by unique micro-scale and temperature-dependent deformation experiments with extremely fast response dynamics.
General statistical and physical models that are predicted to describe the avalanche behavior will be tested with the experimental data, which will help develop new mathematical models that can predict avalanches like these. Since avalanches occur in many other systems, such as earthquakes, disordered materials, or magnetism, the significance of the results to come from this research will extend well beyond the plasticity of metals.
Like Krogstad’s, this award will also partially sponsor a new summer day camp for middle school girls with an interest in materials science and engineering. Maass said while the GLAM camp is amazing, it is only for high school girls, and it seemed like that experience for middle school girls was missing. Middle school students have had less experience with summer camps and potential college majors than their older counterparts in the high school GLAM camp; this will be an unprecedented opportunity for those girls to start pursuing interests in Science, Technology, Engineering, and Mathematics (STEM) education with materials at a young age.
“To receive this award is wonderful,” Maass said. “It allows me to focus on a research direction I have been thinking about for a few years, and I am very happy to see these ideas being recognized by my peers. I am also excited about contributing with a novel outreach program to all the excellent activities in place on campus.”