MSE 298 Seminar (Zoom): The Role of Interfaces in Mechanical Response and Radiation Resistance of Materials

Zoom: Meeting ID 982 8379 4389, Passcode 380564

Abstract: Development of new cost-effective, energy-efficient, and safe technologies for energy production and transportation poses ever-increasing demands on materials stability and durability in harsh environments. In these applications, materials may be exposed to a combination of mechanical stresses, radiation, high temperature and corrosion attack. Engineering of interfaces has been shown as a promising way to control the response of materials to the above harsh environments. For example, in metals, a large fraction of interfaces can lead to a superior radiation resistance, since interfaces can serve as sinks for radiation-induced defects. Interestingly, ceramics interfaces have been shown both to increase and to decrease radiation resistance, even nominally for the same material. In addition, the atomic and the chemical structures of interfaces may evolve when the material is driven out of equilibrium by high temperature or irradiation, which can affect the plethora of properties that are relevant for performance of structural materials in harsh environments.
In this talk, I will discuss the role that materials interfaces play in response to radiation and/or mechanical stresses, focusing on high-temperature ceramics and intermetallics. I will demonstrate that in ceramics, the effects of interfaces are closely coupled to the complex energy landscape for defect reactions, leading to surprising new phenomena. For example, we discovered that even though ceramics form line compounds, radiation can cause segregation of constituent elements to grain boundaries without precipitating new phases. This phenomenon is known as radiation-induced segregation, and it is expected to have a significant impact on corrosion resistance. Secondly, although radiation generally causes degradation of materials properties, it can be also used as a tool to improve materials. In particular, I will demonstrate that radiation can be used as a tool for nano-engineering of interfaces in SiC-carbon nanotube composites, leading to significant improvements of fracture toughness. Finally, I will present our recent discovery of new mechanisms of ductility in intermetallics. I will discuss how these mechanisms are coupled to grain boundaries, leading to surprising grain-size effects in mechanical response and opening up the possibility of designing materials that are both strong and ductile.

Bio: Izabela Szlufarska is a Harvey D. Spangler Professor of Engineering at the University of Wisconsin-Madison and the chair of the Materials Science & Engineering Department. Szlufarska develops and employs theoretical and computational tools to address problems in the areas that span mechanical behavior of materials, interfacial chemistry, and materials design for extreme environments (corrosion, high temperature, radiation). Szlufarska published approximately 130 peer-reviewed papers, including multiple publications in Science and Nature journals. Among her awards are the NSF CAREER award, Air Force Office of Scientific Research Young Investigator Award, H.I. Romnes Faculty Fellowship, and Vilas Associate Professorship. She was also placed on the National Academy of Engineering list of Frontiers of Engineering. Professor Szlufarska has served in a number of leadership and advisory roles, including service as a chair of the Materials Research Society meeting (2016), panel lead for the Department of Energy workshop on basic research needs for future nuclear energy, and editor-in-chief for the journal Current Opinion in Solid State and Materials Science.