Transmission electron microscopy specimen preparations of isothermally oxidized FeCrAl alloy by using focused ion beam system

A Focused Ion Beam (FIB) system was applied for Transmission Electron Microscopy (TEM) specimen preparation of isothermally oxidized FeCrAl alloy. The specimens of FeCrAl alloy were isothermally oxidized in air at 1200 °C for 2 minutes, 10 minutes, 2 hours and 100 hours. Preparation of the specimens was carried out by using Focused Ion Beam (FIB ) system. Characterization was carried out using TEM for microstructure analysis and diffraction pattern. Energy Dispersive X-Ray Spectroscopy (EDX) was used to determine element distribution. Electron Energy Loss Spectroscopy (EELS) was used to determine light element and oxygen. The TEM images show remarkable microstructure of the specimens, and generally show a multi-layer microstructure. The TEM images clearly show Tungsten (W) and Gallium (Ga) layers from specimen preparation, Al₂O₃ layer, spinel (MgAl₂O₄), Cr₂O₃ scales, pores, (Zr, Hf, Mg) Oxides and (Y, Zr)-Oxides in the oxide layer, and Hf/Zr-C cluster. The FIB system used in this work proved its ability and reliability to produce specimens for microstructural and elemental studies of FeCrAl alloy. (author)