Advanced Electron Microscopy

Overview

Advanced electron microscopy techniques, particularly Transmission Electron Microscopy (TEM), have become essential for characterizing small-scale features in materials, such as short-range order, precipitates, and atomic arrangements. In recent studies, TEM has been used to directly observe the chemical short-range order in 25 wt% Mn steel, providing insights into atomic-level interactions and alloy behavior. Similarly, TEM has revealed the atomic structure of β″ precipitates in high-Si Al-Si-Mg alloys, shedding light on the precipitation mechanisms that influence material properties. Additionally, TEM was employed to characterize the crystallographic structure of Al18Mg3Ti2 intermetallics in Al–Zn–Mg–Cu–Zr–Ti alloys, allowing for a deeper understanding of phase stability and their role in alloy performance. These applications highlight the power of TEM in investigating complex material systems at the atomic scale, providing critical information for improving material design and performance.

Representative Publications and Presentations

- Direct observation of chemical short-range order in 25 wt% Mn steel via transmission electron microscopy.
Saif Haider Kayani, Sangeun Park, Jung Gi Kim, Jae Bok Seol, Hyokyung Sung
Scripta Materialia 213 (2022) 114642.
DOI

- The influence of chemical short-range order on the nanoindentation properties of high-entropy alloys prepared via laser powder bed fusion.
Shuai Guo, Meng Wang, Qian Wang, Shang Sui, Saif Haider Kayani, Jae Bok Seol, Pengcheng Zhu, Anfu Guo, Xin Lin, Weidong Huan
Materials Characterization 207 (2024) 113560.
DOI

- Crystallographic characterization of Al18Mg3Ti2 intermetallic phase in Al–Zn–Mg–Cu–Zr–Ti alloy.
Sang-Hwa Lee, Saif Haider Kayani, Jae-Gil Jung, Sung-Il Baek, Min-Seok Kim, Young-Kook Lee, Kwangjun Euh
Journal of Alloys and Compounds 844 (2020) 156173.
DOI

- Atomic structure of β″ precipitates in high-Si containing Al-Si-Mg alloy.
Saif Haider Kayani, Sang-Ik Lee, Yoon-Ho Lee, Jung-Moo Lee, Kwangjun Euh, Young-Hee Cho (under review)

- Vacancy-dragged Zr segregation at U1/Al interfaces in Al-Si-Mg cast alloy.
Saif Haider Kayani, Jung-Moo Lee, Kwangjun Euh, Dongwon Shin, Young-Hee Cho, Gang Sha
The 23rd Conference on International Exchange of Professionals, 2025.