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

Specimens were prepared for transmission electron microscope (TEM) examinat ion from both FeAl and WC powders using a focused-ion beam (FIB) miller. Th ese powders are used in preparation of FeAl-WC metal matrix composites (MMC s), and TEM examination is desired for comparison with the consolidated pro duct. Due to the geometry of the powders, specimen preparation difficulties have precluded high-resolution examination of these materials to date. Spe cimens were successfully prepared by imbedding powders in resin and thinnin g using a FIB. A large thin area was prepared (similar to 10 x 10 mum) in a relatively short period of time (similar to2 h milling time). Chemical ana lysis revealed some evidence of redeposition, but negligible gallium implan tation. Ion damage was observed in the metallic powder, but not in the cera mic powder. Both materials retained their crystallographic integrity. (C) 2 001 Elsevier Science Inc. All rights reserved.