Tribological characteristics of various surface coatings for rotary compressor vane

In developing rotary compressors that will use HFC refrigerants, the biggest challenge is overcoming wear of the various components. In particular, severe wear between the vane and roller sliding pair is a persistent problem. In this study several hard coatings were applied on vane surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. Coatings with very high hardness, namely TiAlN and DLC, produced high friction and severe wear on the roller, and thus seem unsuitable for this application. Softer WC/C (tungsten carbide carbon) coatings formed durable tribe-films on the mating surface and showed good tribological properties. TiN coated vanes showed good wear resistance properties but produced high friction. Ion nitriding is not suitable for this application since the durability of ion nitride layer appeared to be insufficient to sustain the cyclic contact stress encountered in the vane-roller system. (C) 1998 Elsevier Science S.A. All rights reserved.