S4E6

Abstract

Light alloys of Aluminum (Al) and Magnesium (Mg) hold great promise in many structural applications, but our success in strengthening these environmentally friendly metals has been remarkably different. While significant improvement has been achieved in developing high-strength Al alloys that have lightened vehicles/structures, the anisotropic hexagonal crystal symmetry and complex plasticity mechanisms have made the design of high-strength Mg alloys a challenging exercise. In this talk, I will describe our design of unique thermo-mechanical processing pathways for several model, binary Mg alloys, where nucleation-controlled kinetics dominate the microstructural evolution. Synergistic experimental and computational efforts unravel fundamental ways to strategically tune atomic-scale defects to generate fine solute clusters and achieve a high density of nanoscale precipitates. These novel microstructures show great promise in dramatically improving Mg alloy properties across diverse, dynamic environments. Within this presentation, I will also highlight our Mg database project, a new materials informatics effort for enabling the high-throughput inverse design of next-generation alloys.

Introduction of speaker

Dr. Suhas Eswarappa Prameela is a post-doctoral scholar at Hopkins Extreme Materials Institute (HEMI), Johns Hopkins University. He is currently a member of Materials in Extreme Dynamic Environments (MEDE) and Materials Science for Extreme Environments (MSEE) research consortia. His dissertation work has been recognized by the People’s choice-Best Poster Award at the Mach conference and featured in Nature Reviews Physics. His research interests span metallurgy, high-throughput alloy development, extreme environments, mechanical behavior, sustainable materials, metal additive manufacturing, and materials informatics.

Abstract

The development of advanced materials with desired mechanical properties requires a fundamental understanding of the physics of deformation and failure behavior of materials over a wide range of length and time scales. Measurement of strength at high dynamic pressures is critical for applications such as space shielding, hypersonic vehicles, and armor protection. However, the experimental techniques to investigate the strength of materials at high pressures are limited. This talk will present the recent advancements in pressure shear plate impact (PSPI) technique to study the material behavior at high dynamic pressures involving shock waves. The high-pressure PSPI experiments provide a unique methodology for extracting the complete stress-strain behavior of materials at pressures approaching 50 GPa. The results from experiments on oxygen-free high conductivity (OFHC) copper and pure iron at pressures ranging from 10 to 43 GPa and strain rates ~ 10^5 s^-1 will be presented. A substantial pressure hardening is observed for both coppers. The experimental results reveal that the scaling of shear modulus and strength with pressure is quite different for copper, previously assumed to be the same.

Introduction of speaker

Dr. Suraj Ravindran is currently a postdoctoral scholar at the Graduate Aerospace Laboratories, California Institute of Technology (GALCIT), working on the high-pressure and high-strain rate dynamic behavior of materials. He received his Ph.D. in mechanical engineering from the University of South Carolina in 2018. He worked as an Edison Engineer in General Electric Aviation for two years after completing his master’s in mechanical engineering at the Indian Institute of Technology, Mumbai, in 2011. He was recognized for his research in energetic materials and high-pressure strength of materials with the Society for Experimental Mechanics’ R. E. Peterson award twice for the best paper published in the Journal of the Dynamic Behavior of Materials in 2018 and 2021. He was also the recipient of a Breakthrough Graduate Scholar Award from the University of South Carolina in 2017 that recognizes doctoral students who show promise for distinguished careers in research. His research interests are in the multiscale mechanics of materials at extreme pressures, strain rates, and temperatures.