Materials that employ microstructure features to manage radiation damage and maintain high-temperature mechanical properties are especially desirable for improving the safety and efficiency of advanced nuclear reactors. High crystallization temperature amorphous ceramics and nickel-based alloys are very promising candidates but have some challenging issues. Amorphous ceramics exhibit ‘brittle-like’ behavior though they exhibit superior thermo-mechanical properties and structural stability at high temperatures and under irradiation. We propose to manipulate microstructures of amorphous ceramics via self-patterning amorphous Ni-rich ceramic nanoclusters (referred to as amorphous ceramic composites, ACCs) to improve the ductility of amorphous ceramics while retaining their superior thermo-mechanical properties. Nickel alloys are used in Molten Salt Reactors but sufficient irradiation resistance, improved helium management, elevated-temperature strength, and the resistance to neutron irradiation-induced loss of creep ductility are urgently demanded. We propose to self-pattern nanosized, thermally stable, radiation-tolerant amorphous ceramic particles in nickel alloys (referred to as amorphous ceramic reinforced metallic alloys, ACMs) in order to trap and manage helium and irradiation-induced defects at the matrix-particle interfaces, and retain high-temperature strength by dislocation-particles interactions in addition to solid solution strengthening. In this lecture, we demonstrate our hypothesis with Ni-SiOC ACCs and SiOC-Ni ACMs as a function of constituent fraction and microstructure, assess their mechanical and irradiation properties, and discuss the effect of alloying elements on microstructure and mechanical properties of metal-amorphous ceramic nanocomposites.
Dr. Jian Wang is a full professor of Materials and Mechanical Engineering at the University of Nebraska-Lincoln. He received his Ph.D from Rensselaer Polytechnic Institute, Troy, NY, USA, in 2006 and worked at Los Alamos National Laboratory (LANL) for 9 years (2006-2015). His research focuses on quantitatively exploring the structure-properties relations of materials using multi-scale theory, modeling and experimental methods and techniques. He was awarded the LANL Distinguished Postdoctoral Performance Award (2009), the LDRD/Early Career Award (2011), TMS MPMD Young Leader Award (2013), International Plasticity Young Research Award (2015), Materials Today Rising Star Award in the category of Materials Genome Innovation (2018), and TMS MPMD Distinguished Scientist/Engineer Award (2022). He served as Editorial Board of International Journal of Plasticity (2015~), Materials Research Letters (2016~), and six others. He has published more than ~300 peer-reviewed papers (> 15,000 citations and H-index = 74; 9 papers featured as Journal cover), and delivered 150+ invited/keynote lectures.