Three-body wear is important in many industrial processes. A laboratory study was performed to follow the response of highly polished thermal spray coating surfaces to degradation by hard titanium dioxide particles. A scanning electron microscope, a white light interferometer and a gloss meter were used to evaluate surface structure and texture of the aspolished and abraded surfaces. Tungsten carbide coatings with differing binder material and applied by different processes all degrade by the same mechanism: softer material is worn away by the hard TiO2 particles until the remaining structure consists of the hardest carbides protruding above the general surface plane. This structure is obtained in spite of significant differences in other surface properties such as roughness (Ra) and gloss number. If a more uniform wear surface is desired the carbide spacing must be reduced so that the coating more effectively presents a carbide surface to the TiO2 particles.