Transmission electron microscopy of deep etched cementite

A novel transmission electron microscopy (TEM) sample preparation technique was applied during a study of proeutectoid cementite precipitates in a Fe- 1.34 wt.% C-13.0 wt.% Mn alloy. In isothermally transformed specimens, the material contains interconnected networks of grain boundary and Widmanstatt en cementite precipitates. By immersing conventionally prepared (dimpled an d electropolished) TEM specimens in an etching solution, the three-dimensio nal morphology and internal structure of entire electron transparent cement ite precipitate networks were revealed to provide insights that were not pr eviously possible. This paper describes the experimental technique and illu strates the benefits of this technique by comparing present results with ob servations of thin foil specimens of the same alloy. (C) 2000 Elsevier Scie nce Inc. All rights reserved.