Structure and wear mechanisms of nano-structured TiAlCN/VCN multilayer coatings

Dry sliding wear of transition metal nitride coatings usually results in a dense and strongly adhered tribofilm on the worn surface. This paper presents detailed electron microscopy and Raman spectroscopy characterizations of the microstructure, a newly developed multilayer coating TiAlCN/VCN and its worn surface after pin-on-disc sliding wear against an alumina ball. The friction coefficient in a range of 0.38–0.6 was determined to be related to the environmental humidity, which resulted in a wear coefficient of the coating varying between 1017 and 1016 m3 N1 m1. TEM observation of worn surfaces showed that, when carbon was incorporated in the nitride coating, the formation of dense tribofilm was inhibited.