Grain Boundary Chemistry Effects on Local Stress Relaxation
Materials Science and Engineering Seminar
Prasad Pramod Soman, PhD Candidate
Department of Materials Science and Engineering
Michigan Technological University
Abstract: Nano-indentation studies at specific grain boundaries with and without solute segregation are utilized to interrogate the kinetics of local stress relaxation. Grain boundary and surface layer doping was carried out by vapor phase deposition and drive-in diffusion to engineer the grain boundary chemistry. Results of indentation at specific grain boundaries in high purity Fe at different indentation strain rates is compared to the same grain boundaries where the surface layer has been doped with Ti (to create interstitial free steel) or with carbon. Nano-indentation stress relaxation processes at the grain boundary and adjacent grain interiors under constant strain rate conditions are analyzed together with stress relaxation under loading rate disruption. Initial stages of the analysis indicate that the a thermal (long range) stress and activation volume at the grain boundary can be distinguished from that of the adjacent grain interiors.
Bio: Prasad is currently in his 4th year of PhD and his work is focused on investigating the role of grain boundary geometry and chemistry in materials failure, under guidance from Prof. Hackney and Prof. Herbert.
Tuesday, November 19 at 11:00 am to 12:00 pm
A. E. Seaman Mineral Museum, 610
1404 E. Sharon Avenue, Houghton, MI 49931