TEM Sample Preparation of a Hard Metal by Semiautomatic Wedge Polishing

Sintered hard metals like tungsten car-bide compounds are a challenge for TEM sample preparation due to the diverging properties of the individual components. Especially when both very thin as well as large areas are required, for example for nanoanalysis investigations, conventional preparation techniques like ion milling and FIB preparation are often incapable of de-livering samples of necessary quality. In this study, the preparation of a hard metal consisting of a tungsten carbide/cobalt compound via a technique called “Wedge Polishing” is described, along with the re-sults of concomitant TEM investigations. The impact of the preparation procedure on the crystallographic structure of the material is discussed, and a post-treatment process to dispose of these artefacts is presented.