Preparation of transmission electron microscope specimens from FeAl and WC powders using focused-ion beam milling

Specimens were prepared for transmission electron microscope (TEM) examination from both FeAl and WC powders using a focused-ion beam (FIB) miller. These powders are used in preparation of FeAl–WC metal matrix composites (MMCs), and TEM examination is desired for comparison with the consolidated product. Due to the geometry of the powders, specimen preparation difficulties have precluded high-resolution examination of these materials to date. Specimens were successfully prepared by imbedding powders in resin and thinning using a FIB. A large thin area was prepared (∼10×10 μm) in a relatively short period of time (∼2 h milling time). Chemical analysis revealed some evidence of redeposition, but negligible gallium implantation. Ion damage was observed in the metallic powder, but not in the ceramic powder. Both materials retained their crystallographic integrity.