MECHANICAL AND TRIBOLOGICAL PROPERTIES OF MULTILAYERED PVD TIN CRN, TIN/MON, TIN/NBN AND TIN/TAN COATINGS ON CEMENTED CARBIDE/

Four different multilayered coatings TiN/CrN, TiN/MoN, TiN/NbN and TiN /TaN, were deposited on cemented carbide. A hybrid PVD process consist ing of ion plating (TiN) and magnetron sputtering (CrN, MoN, NbN and T aN) was used. The chemical and phase composition, morphology and micro structure of the coatings were assessed using auger electron spectrosc opy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy, respectively. In addition, all coatings were char acterised with respect to their residual stress, hardness, cohesion/ad hesion and abrasive wear resistance. A PVD TiN coating was used as a r eference throughout the investigation. All coatings exhibited a cubic NaCl structure. Furthermore, ail multilayered coatings, except TiN/MoN , were found to have a strongly preferred (200) orientation. TiN/MoN d isplayed a mixture consisting of (111), (200) and (220) orientations. TiN displayed a (111)-preferred orientation. It was found that the mec hanical and tribological properties of the multilayered TiN/metal nitr ide coatings, in general, were superior to those of homogenous TiN. Th e overall best performance was found for the TiN/CrN coating, whereas TiN/TaN showed the highest abrasive wear resistance. (C) 1998 Elsevier Science S.A.