A. Wank, A. Schwenk, GTV Verschleiss-Schutz GmbH, Luckenbach, Germany; B. Wielage, T. Grund, E. Friesen, H. Pokhmurska, TU Chemnitz, Chemnitz, Germany
For deposition of protective coatings different coating techniques are available. Extended evaluation of various deposit types and materials is necessary for selection of the most appropriate coating for specific application fields and demands. Subject of this work are thermally sprayed functional coatings applied as wear (and corrosion) protective layers. Based on former investigations examination of optimized HVOF sprayed hardmetal coatings (WC-Co(Cr), Cr3C2-NiCr), conventionally flame sprayed and remelted self fluxing alloy coatings reinforced by hardmetal and APS sprayed oxide ceramic coatings (Al2O3-TiO2, Cr2O3) is done in comparison to thick hard chromium platings. Two abrasive wear tests - dry and with superposition of corrosive exposure - are applied according to ASTM G65 (Rubber Wheel test) and ASTM G75 (Miller test). Additionally coating microstructures are evaluated by SEM and micro hardness is measured in order to deduce wear mechanisms.
Summary: Subject of this work are thermally sprayed cermet and ceramic coatings applied as wear (and corrosion) protective layers. Two ASTM abrasive wear tests - dry and with superposition of corrosive exposure - are applied to examine the behaviour of these coatings in comparison to thick hard chromium platings.
