Application of electron backscatter diffraction in facet crystalline orientation study of Al-Cu-Fe alloy

Facets are flat faces of a single crystal, which are typically parallel to the low-energy lattice planes. The orientation of a facet can sometimes be determined by simple visual examination, as in the case of the gemstone industry. Facets on microscale particles often do not correspond to the expected results of equilibrium, and the smaller physical size presents a challenge in observation. Using a facet observed on spherical particles of 20 mu m diameter in alloys of Al60Cu25Fe15 composition as an example, a procedure to determine facet orientation based on the combined usage of Scanning Electron Microscope (SEM) and Electron Backscatter Diffraction (EBSD) has been proposed and tested. Out of three types of facets found, the crystalline orientation of one type is determined by two approaches: by examination of facet relative layout and by orientation analysis based on the usage of SEM-EBSD. The former is along the traditional line of visual examination and the latter represents an attempt to expand the application of EBSD in a different field. Both approaches proved that the surface of the facet is parallel to the {100} lattice plane of a cubic phase. The experimental details and the strength of SEM-EBSD in such application are discussed.