Metallographic Preparation of Zn-21Al-2Cu Alloy for Analysis by Electron Backscatter Diffraction (EBSD)
Abstract Samples of Zn-21Al-2Cu alloy (Zinalco) that will be heavily deformed were prepared using five different manual mechanical metallographic methods. Samples were analyzed before tensile testing using the orientation imaging microscopy-electron backscatter diffraction (OIM-EBSD) technique. The effect of type and particle size during the final polishing stages for this material were studied in order to identify a method that produces a flat, damage free surface with a roughness of about 50 nm and clean from oxide layers, thereby producing diffraction patterns with high image quality (IQ) and adequate confidence indexes (CI). Our results show that final polishing with alumina and silica, as was previously suggested by other research groups for alloys that are difficult to prepare or alloys with low melting point, are not suitable for manual metallographic preparation of this alloy. Indexes of IQ and CI can be used to evaluate methods of metallographic preparation of samples studied using the OIM-EBSD technique.
Orientation Imaging Microscopy: Sample Preparation for Heavily Drawn Copper wires
The use of Orientation Imaging Microscopy (OIM) as a microcharacterization technique has evolved into a standard analytical tool for studying deformed or processed materials [1,2]. OIM technique relies on accurate orientation data via electron backscattered pattern (EBSP) measurements to recreate the microstructure of materials. In spite of the considerable advances that have been made on this technique, it is still inadequate for use in the study of heavily deformed materials [3]. This is partly due to lack of appropriate specimen preparation methods, and partly due to the interference of the fine substructures or/and grain size with the formation of the EBSPs in such materials [3]. It is therefore important to assess the extent to which specimen preparation can improve the quality of OIM data obtained from heavily deformed materials.
Initial electron back-scattered diffraction observations of cerium
The first electron back-scattered diffraction Kikuchi patterns and grain orientation maps were captured for pure n-phase (fcc) Ce. The sample preparation technique used for electron back-scattered diffraction orientation mapping of this surface-reactive metal included ion sputtering the surface using a scanning Auger microprobe followed by vacuum transfer of the sample from the scanning Auger microprobe to the scanning electron microscope. The effect of ion sputtering on the microstructure as well as preliminary electron back-scattered diffraction microstructural characterization is presented. Based on the sputtering data, the room-temperature diffusivity of O in n-Ce was estimated.