High-temperature tribological properties of plasma-sprayed metallic coatings containing ceramic particles

Plasma-sprayed metal-base coatings containing ceramic particles were considered for high-temperature sealing of a moving metal component with a dense silica-base ceramic preheated at 800 ‡C. Selected metal powders (NiCoCrAlY, CuNi, CuNiIn, Ag, Cu) and ceramic particles (boron nitride, Zeta-B ceramic) were agglomerated to form suitable spray powders. Plasma-sprayed composite coatings and reference materials were tested in a modified pinion-disk apparatus in which the stationary disk consisted of a dense silica-base ceramic piece initially heated at 800 ‡C and allowed to cool during tests. The influence of single exposure and repeated contact with ceramic material on coefficient of friction, wear loss, and damage to the ceramic piece was evaluated.