CAREER: Design and Development of Nanoscale Strengthened Materials for High Temperature Applications

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

0548259 Wirth TECHNICAL: Nickel-based super alloys are outstanding high temperature materials. However, the desire to reach even higher operating temperatures as a way to improve performance and thermodynamic efficiency (thereby reduce fuel consumption and pollution) requires the development of a new class of high-temperature materials. Research will improve high temperature creep strength of NiAl and IrAl intermetallics by incorporating a high number of thermally stable Y-Ti(Zr,Hf)-O nanoclusters. Research would involve computational modeling, including electronic structure calculations, atomistic lattice and off-lattice Monte Carlo simulations, and molecular dynamics simulations, to investigate the structure, composition and thermal stability of the nano-clusters. Materials will be prepared by mechanical alloying and consolidation through hot isostatic pressing. Advanced experimental characterization techniques, combined with micro-hardness measurements will be used to investigate the material microstructure and to evaluate thermal stability during long-term annealing. In particular, the size, density, and composition of the nanoclusters will be assessed and compared to the computational predictions. Computational molecular dynamics simulations will be used in the later stage of the program to investigate the atomistic sequence of events controlling dislocation interaction and detachment from the nanoclusters. NON-TECHNICAL: Results would lead to an optimized alloy system for high temperature applications for jet engines, power plant applications, etc. It would also provide an inter-disciplinary environment to attract and educate graduate students in materials science research. This will be achieved by incorporating computational and experimental tools as well as the specific knowledge gained from this program into classroom teaching, research seminars, and educational outreach activities. Java-based modules that demonstrate materials behavior will be developed during this program for undergraduate and graduate courses, and translated into a format applicable to educational outreach activities for high school students. Outreach activities will be aimed at high school students will specific focus on students from minority, underrepresented, or low-income backgrounds in the Berkeley and Oakland school districts.