Hillert Materials Modeling Colloquium series XIX: Critical stress determination in metallic materials
Professor Huseyin Sehitoglu is editor of Shape Memory and Superelasticity journal. In this presentation he discusses new theoretical developments in areas like interfaces in martensites, the evolution of slip in shape memory alloys and the determination of Critical Resolved Shear Stress (CRSS). He also talks about the application of these theories.
This presentation discusses new developments in materials science in several areas. Firstly, we discuss the understanding of interfaces in martensites and the evolution of slip in shape memory alloys. Secondly, we emphasize the significance of the Wigner-Seitz lattice in the evaluation of misfit energies and dislocation core widths in metals and, ultimately, the determination of Critical Resolved Shear Stress (CRSS). We also explain the application of this theory to negative stacking fault energy multi-component alloys and hcp crystals. Thirdly, we discuss short-range order (SRO) determination that has a crucial impact on the mechanical strength of metallic alloys. We propose that the local ‘change in SRO’ upon slip advance dictates the strengthening, and we focus on the ‘SRO change’ on the slip plane considering the Wigner-Seitz cell.
Publications
ASK.Mohammed, H. Sehitoglu, Strain-sensitive Topological Evolution of Twin Interfaces, Acta Materialia,208 116716, 2021
D. You, O. Celebi, ASK. Mohammed, H. Sehitoglu, Negative Stacking Fault Energy in FCC materials-Its Implications, I. J. Plasticity, 10.1016/j.ijplas.2023.103770, 2023
O. Celebi, ASK Mohammed, H.Sehitoglu, Effect of Dislocation Character on the CRSS, Acta Materialia, 118982, 2023
ASK. Mohammed, OK. Celebi, H. Sehitoglu, Acta Materialia, Critical stress prediction upon accurate dislocation core description, 233, 2022
Lecturer
Professor Huseyin Sehitoglu.
Professor Sehitoglu’s research focuses on the mechanical behavior of materials, phase transformations, twinning, and fatigue. He received his PhD in Theoretical and Applied Mechanics at the University of Illinois, Urbana, in 1983. He is the former Department Head of the MechSE Department and has been Nyquist Chair in the same department since 2008. He advised nearly 150 graduate students, postdocs, and visiting scholars, and has 13 former PhD students in academic positions as Professors. He is Editor of Shape Memory and Superelasticity journal. He received the Khan International Medal in Plasticity in 2021, the ASME Honoraray Membership, 2022, the M. Cohen Award from TMS in 2022, and earlier the Nadai Medal from ASME in 2007. He was Director of the Mechanics and Materials Program at the National Science Foundation from 1991 to 1993.
