Materials under evolution: Highly time-resolved diffraction and thermo-mechanical processes probed by neutrons and synchrotron X-rays

seminars
12.01.2017
14:30
אודיטוריום ע"ש דיוויד וואנג, קומה 3, בנין דליה מידן
Prof. Klaus-Dieter Liss

Prof. Klaus-Dieter Liss
Australian Nuclear Science and Technology Organisation
and University of Wollongong, Australia
Modern synchrotron and neutron radiation facilities allow for probing materials with high time-resolution and in-situ under extreme conditions. This allows for the direct study of ultrasonic wave fields in crystals leading to applications on periodic structural changes in ferroic compounds. I.e. relaxation processes can be followed. Non-periodic processes, such as laser impact can be studied in pump-probe snapshots with sub-nanosecond resolution. Furthermore, in-situ studies have been advanced for the investigation of thermo-mechanical processes in metallic systems. Apart from phase evolution, the complementarity of synchrotron and neutron radiation allows to study the atomic ordering and disordering in titanium aluminide intermetallics. Dynamical theory of neutron diffraction has been employed to study the defect kinetics in metals at very high temperature. Two-dimensional synchrotron X-ray diffractograms have been streaked in time, which leads to the Materials Oscilloscope, allowing to follow microstructural changes upon plastic deformation and eating cycles. These pioneering techniques are demonstrated on selected metal systems with an outlook to the future expanding on structural and functional materials.