New technique for successful thermal barrier coating specimen preparation for transmission electron microscopy

Reliability of thermal barrier coatings (TBC) hinges on the adhesion of a t hermally grown oxide scale to an insulative ceramic topcoat and an underlyi ng metallic bondcoat. The width of the scale and its interfaces makes trans mission electron microscopy (TEM) an appropriate tool for its analysis. How ever, specimen preparation has proven to be a challenging obstacle leading to a dearth of TEM research on TBCs. A new approach to cross-section TBC TE M specimen preparation is described. The principal advantages of this techn ique are reproducibility, reduced specimen damage, and time savings resulti ng from decreased ion milling. This technique has been successfully applied to numerous TBC specimens with various thermal histories.