TiN coatings produced by physical or chemical vapour deposition have been successfully introduced in industry, eg. for cutting and forming of materials. The potential of an additional oxide film on such coatings has been investigated with respect to wear protection. Partial oxidation of TiN coatings was realized by concentrated solar beam irradiation at 800-degrees-C for 10 s. Wear testing under controlled conditions was done by reciprocating sliding of coated flat partially oxidized TiN, as-deposited TiN and bulk Al2O3 samples against non-reactive corundum balls. The wear tracks were investigated by laser profilometry, scanning electron microscopy and atomic force microscopy. The essential benefit of atomic force microscopy appears to be the high resolution study of debris and wear damage on the nanometre scale. This technique appears to be complementary to profilometry and scanning electron microscopy. The coefficient of friction showed higher values on partially oxidized TiN in comparison with as-plated TiN; the lowest value was obtained for Al2O3. Notwithstanding the high coefficient of friction, the wear volume on partially oxidized TiN was considerably smaller in comparison with as-plated TiN owing to a difference in wear mechanism. Small plateaus of compacted wear debris were observed in the wear tracks on the oxidized TiN, while loose wear debris was found in the wear track on TiN.