Oscillating sliding wear of mono- and multilayer ceramic coatings in air

Structural characteristics and mechanical properties of TiN and (Ti,AI)N mo nolayers, and multilayered (superlattice) (Ti,AI)N/TiN coatings deposited o n ASP 23 high-speed steel by different PVD techniques are compared. Coating characteristics such as morphology, composition, cross-sectional structure , hardness and elastic modulus were determined. The effect of TIN interlaye rs on the hardness and the elasticity of multilayered (Ti,Al)N/TiN coatings was investigated. The friction and wear of these coatings were investigated in unlubricated f retting tests (mode I) performed in air of different relative humidities. T he relationship between wear volume and dissipated energy was derived for ( Ti,Al)N-based coatings, and the dependence upon relative humidity was check ed and compared to the one found earlier for TiN coatings. (Ti,Al)N-based c oatings exhibit a lower wear rate (mu m(3) J(-1)) at increasing relative hu midity, whereas TiN has a constant wear rate independently of the relative humidity. Multilayered (Ti,Al)N/TiN coatings show an improved fretting wear resistance in comparison to monolayer (Ti,AI)N coatings. (C) 1999 Elsevier Science S.A. All rights reserved.