Deformation mechanisms in bcc single crystals
The micro-compression technique performed during in-situ Laue diffraction at the MicroXAS beamline of the Swiss Light Source [H. Van Swygenhoven, S. Van Petegem, JOM 62 (2010) 36.] has been used to follow the sequence of activated slip systems in BCC single crystal pillars with diameters of 1-2 micron. Diffraction patterns are obtained in transmission with a 5-23 keV X-ray beam, with FWHM of 0.5-1 μm and complemented with Laue scans allowing the mapping of the spatial distribution of strain gradients in the deformed pillars, providing information on local crystallographic orientations and on the activated dislocation slip systems. In-situ Laue diffraction is for the moment the only technique allowing following the microstructure of micron-sized single crystal pillars during deformation. In other words, this is an ideal technique to address long standing open questions in plasticity of bcc metals
In this project in-situ micro-compression experiments are carried out during Laue diffraction on four bcc single crystal pillars, i.e. Tungsten, Molybdenum, Niobium and Vanadium having different values of Tc.