Transmission electron microscope specimen preparation of metal matrix composites using the focused ion beam miller

Transmission electron microscope samples of two types of metal matrix compo sites were prepared using both traditional thinning methods and the more no vel focused ion beam miller. Electropolishing methods were able to produce, very rapidly, thin foils where the matrix was electron transparent, but th e ceramic rc reinforcement particles remained unthinned. Thus, it was not p ossible in these foils to study either the matrix-reinforcement interface o r the microstructure of the reinforcement particles themselves. In contrast , both phases in the composites prepared using the focused ion beam miller thinned uniformly. The interfaces in these materials were clearly visible a nd the ceramic reinforcement was electron transparent. However, microstruct ural artifacts associated with ion beam damage were also observed. The exte nt of these artifacts and methods of minimizing their effect were dependent on both the materials and the milling conditions used.