Metallographische Präparation von lasergestützt erzeugten Verschleißschutzschichten mit hartmetallähnlichen Gefügen / The Metallographic Preparation of Laser Processed, Protective Wear Resistant Coatings with Hard Metal-like Microstructures

Abstract

In the development of laser fused wear resistant coatings numerous metallographic investigations are required. With their help it is possible within a relatively short space of time to deduce relationships between the microstructure of the coatings produced and the conditions necessary for their manufacture. On the basis of this the conditions of irradiation used can be optimised. The metallographic preparation of coatings with hard metal-like structures has been shown to be problematic. This can on the one hand be attributed to the great differences in hardnesses in the coatings themselves and between the coatings and the substrates, and on the other hand on the often relatively low proportion of matrix metal in the coatings. Investigations have shown that conventional preparation is both time intensive and inadequate due to the lack of edge sharpness achieved between the microstructural constituents of different hardnesses, as well as being subject to carbides breaking out of the surface of the specimen and other such damage. With the use of the grinding-lapping action provided by the New Lam system which results in a basically different method of material removal during preparation, it was possible to achieve specimen preparation free of such deficiencies within a relatively short period of time.