报告题目：On the application of in-situ X-ray imaging techniques in solidification science
主讲人：Ragnvald Mathiesen, Professor, Norwegian University of Science and Technology
报告摘要：Over the last 2-3 decades, X-ray imaging techniques have become well-established methods for in situ studies of solidification microstructure formation in metals and alloys. From the pioneering start with X-radiography limited to spatial resolutions of a few microns at about 1 Hz frame rates, state-of-the art methods of today can provide spatial resolutions beyond 100 nm and full tomographic acquisitions in 100 ms, or radiography beyond 1 kHz frame rates. The seminar will give an overview over various dedicated solidification studies carried out over this period, such as columnar and equiaxed dendritic growth, phase separation and coagulation dynamics in immiscible melts, dendrite fragmentation and coarsening, grain growth in weld pools, dendritic growth under coupled diffusive and convective transport control and pattern formation and growth of regular and irregular eutectics. The seminar will also provide an overview of the different X-ray methods applicable to in situ studies of solidification phenomena, including their special merits and advantages. These will comprise X-radiography, X-tomography, X-topography, ultra-fast polychromatic XRD, as well as X-ray transmission microscopy.
报告人简历： Ragnvald Mathiesen为挪威科技大学物理系教授，欧洲同步辐射光源(ESRF)科学顾问，金属凝固领域国际知名学者，长期从事金属凝固行为与机理同步辐射研究，为金属凝固同步辐射研究开拓者。迄今为止，已在包括PRL, Acta Mater.等在内的一流期刊发表论文100多篇。做邀请报告48次，其他各类报告180多次。