CAREER: Enabling High-throughput Creep Testing of Advanced Materials through in-situ Micromechanics and Mesoscale Modeling

University Of Miami, Coral Gables FL

Investigators

Abstract

Crystalline materials exposed to medium to high homologous temperatures can result in progressive deformation, called creep, which often determines the end of a material's service life. It may result in the catastrophic rupture of critical components. This Faculty Early Career Development (CAREER) award supports fundamental research enabling novel micromechanical creep testing techniques, and it furthers the fundamental understanding of creep deformation mechanisms in advanced materials such as multi-principal element alloys. This research contributes to enabling superior creep-resistant materials, which benefit critical sectors of the U.S. society such as energy, transportation, aviation, propulsion, and space exploration, with far-reaching beneficial consequences on human well-being, economics, and environmental sustainability. This award also integrates research and education by supporting various outreach activities and creating new opportunities for underrepresented students to engage in scientific research. Creep strength is arguably the most important mechanical property for structural alloys operating at high temperatures. Standard creep tests are expensive and time-consuming, and they require bulk samples. When developing new materials, however, high-throughput techniques that are capable to test small samples are typically required. This is particularly important in the case of multi-principal element alloys, due to needs to explore their vast compositional space. Nanoindentation is a high-throughput test suited for small samples, and it has been the primary technique to screen not only creep, but also fatigue, and fracture properties of these materials. This CAREER award funds research that attempts to advance nanoindentation as a high-throughput technique for fast screening of creep properties. The research combines multiscale modeling, micromechanical tests carried out at high temperature within a scanning electron microscope, and machine learning to establish a relation between nanoindentation and uniaxial creep properties. The research also broadens the fundamental understanding of high-temperature deformation mechanisms in body-centered cubic refractory multi-principal element alloys. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.