The effects of a third element on structure and properties of W–C/N

We have studied the effect of adding different metallic (Fe, Co, Pd, Cr, Ti, Ni,…) and non-metallic (Si) elements to the structure of W–C/N-based films deposited by sputtering. The influence of a Group VIII element on interstitial carbides has also been studied in order to clarify its role in structure amorphization. The results obtained for films in the as-deposited condition show different types of structures with various degrees of structural order, depending on the type and content of the element added. The new coatings can be structurally stable or metastable, formed either by structures with enlarged solubility domains or amorphous structures, with or without nanophases inside. The transformation kinetics of the metastable phases with temperature for different types and contents of a third element added have been investigated. From the results obtained at high temperatures, we conclude that the chemical and structural behavior mainly depends on the position of the third element in the Periodic Table, and on its affinity to carbon and nitrogen. Strong and moderate carbide/nitride-forming elements improve the phase stability at high temperatures; the other elements lead to structural changes in the operating temperature range of the coating during the technological application.