Investigations of Fine Grained Metallic Materials by Means of Orientation Maps in Transmission Electron Microscope
|Periodical||Solid State Phenomena (Volume 186)|
|Main Theme||Electron Microscopy XIV|
|Edited by||Danuta Stróż and Krystian Prusik|
|Citation||Magdalena Bieda, 2012, Solid State Phenomena, 186, 53|
|Online since||March, 2012|
|Keywords||Diffraction Patterns, Orientation Microscopy, Plastic Deformation, Transmission Electron Microscope|
New subdivision of microscopic investigation called Orientation Microscopy (OM) is already well known in scanning electron microscope (SEM). Needs for investigation in nanoscale contribute to development of an appropriate method for transmission electron microscope (TEM). Automated acquisition and indexing of diffraction patterns, necessary for creation of orientation maps in TEM, cause more difficulties then in SEM. Nevertheless, the techniques of OM are also being developed in the Transmission Electron Microscope (TEM). Microdiffraction has been successfully introduced for creating such maps. Individual orientation measurements, which appeared in the convergent beam mode, can be used for quantitative description of microstructure of fine grained and deformed materials. The idea of the operation of the automated system in transmission electron microscope (TEM) which is developed in IMIM PAS relies on an automatic (with control position of the beam) acquisition of diffraction patterns using digital CCD camera, and indexing them, and then on the analysis of the set of individual crystallographic orientations. The graphic presentation of received sets of orientation can be analysed in order to obtain parameters and characteristics such as texture characteristics, characteristics of grain boundaries (based on orientation relationship) or the stereological characteristics. To illustrate application of this system, orientation maps measured in cold-rolled polycrystalline aluminium and its alloy 6013, and in multi-phase alloys of Fe-Cr-Co system after severe plastic deformation are presented.