LGF Seminar – Yubin Zhang (DTU, Denmark) – November 16, 2023

Yubin Zhang (DTU, Denmark) is visiting our laboratory. On this occasion, he will give the following seminar.

Title

High-resolution 3D synchrotron X-ray techniques for recrystallization studies

Abstract

After 20 years of development, the current generation of synchrotron techniques, such as 3D X-ray Laue microdiffraction using a differential aperture and diffraction contrast tomography, have matured into powerful tools for measuring the crystallographic orientations, morphologies, and local lattice strains of grains within bulk samples in full 3D. In this presentation, several well-designed experiments using these techniques to study recrystallization will be presented, including nucleation at hardness indents, formation of residual stresses within recrystallizing grains, and growth of several nuclei into a well-characterized deformation matrix. It is shown that with high-resolution (~1µm) mapping of both the deformation matrix and the recrystallized grains, the local heterogeneous nucleation and growth of recrystallized grains can be correlated with the local deformation microstructure. The critical need for full-field microstructural characterization for recrystallization studies will be emphasized, and new possibilities offered by laboratory 3D X-ray techniques will be briefly discussed.

Biography

Dr. Yubin Zhang obtained his PhD from Tsinghua University in China in 2009 in the field of materials science and engineering. He is currently working in the Department of Civil and Mechanical Engineering at the Technical University of Denmark as a senior scientist. His research focuses on 3D/4D studies of microstructure and micro-strain/stress evolution during plastic deformation and annealing of metals and alloys using synchrotron X-ray methods. Over the last 15 years, he has conducted more than 40 synchrotron experiments at ESRF, DESY, and APS. Recently, he has also been involved in developing laboratory X-ray methods for non-destructive 3D characterization. He has published more than 80 journal articles and has an H-index of 25.