Seminar & Colloquium
[세미나: 8월 4일(목), 오후 4시] Dr. Hyunseok Oh, MIT
Title
How can alloy design push limits? Making sense and use of complexity
Speaker
Dr. Hyunseok Oh, Post Postdoctoral Associate, Department of Materials Science and Engineering, Massachusetts Institute of Technology
Education
- Mar 2007 - Aug 2011, B.S. in Materials Science and Engineering, Seoul National University
- Mar 2012 - Feb 2018, Ph.D. in Materials Science and Engineering, Seoul National University
Thesis Title: Tailor-made design of complex concentrated alloys
Thesis Supervisor: Prof. Eun Soo Park
Professional experiences
- Mar 2015 - Feb 2016, Visiting Student, Max Planck Institute for Iron Research, Germany (Prof. Dierk Raabe)
- Mar 2018 - Aug 2018, Postdoctoral Associate, Seoul National University
- Sep 2018 - Current, Postdoctoral Associate, Massachusetts Institute of Technology, USA (Prof. C. Cem Tasan)
| Date | Thursday, August 4th, 2022
| Time | 16:00 ~
| Venue | 온라인: https://snu-ac-kr.zoom.us/j/2018801489
회의 ID: 201 880 1489
[Abstract]
Over the last century, the compositional and microstructural complexities of alloys have dramatically increased in response to accelerating demands for component safety, efficiency, and resistance to harsh environments. However, interactions between the multi-scale complexities that govern the engineering properties can rarely be explained by practical and well-established methods such as mean-field averaging, which renders alloy design an empirical trial-and-error undertaking.
In this seminar, I will introduce my research approach to overcoming property trade-offs in alloys. This approach harnesses compositional/microstructural complexities, using both metallurgical principles and different characterization techniques (e.g., in-situ scanning electron microscopy, synchrotron). First, I will present the development of a Ni-V alloy, which exhibits a far greater strength-ductility combination than any other existing face-centered cubic complex-concentrated alloy (CCA), by using a simple parameter: electronegativity difference for solid-solution strengthening. Second, I will highlight a martensitic stainless steel, which achieves improved ductility without sacrificing strength by introducing austenite grains that remain as strong as the martensitic matrix they are embedded in. Third, I will discuss the Co-Ni-Cr-N CCAs exhibiting a desirable plasticity mechanism change (from martensitic transformation to faulting) induced by short-range ordering. These investigations demonstrate how blending metallurgical principles with characterization techniques can produce generic design guidelines to effectively explore the immense degrees of freedom in compositional and microstructural space and achieve superior property combinations.
| Host | Prof. Heung Nam Han (02-880-9240)