Investigation of interfaces of chemically vapour deposited SiC, SiC-Ti(N,C) multilayer coatings on WC-Co based cermets

Abstract

Abstract The direct deposition of silicon carbide by pyrolysis of methyltrichlorosilane in Ar-H 2 atmosphere onto WC-Co based cermet substrates causes the formation of cobalt silicides, the secondary η-phase, and consequent adhesion failure. To minimize this adhesion failure, layers based on TiN, Ti(C,N) were deposited. Investigations of the chemical composition of chemically vapour deposited multilayers and interfaces were performed using scanning electron microscopy, X-ray diffraction and Auger spectroscopy techniques; the adhesion was evaluated using the scratch test. Promising mechanical properties (adhesion and hardness) of the chemically vapour deposited SiC were obtained using these intermediate multilayers. The average stress was also calculated as a suitable adhesion parameter. The relationship between the interface composition and the quality of adhesion is also discussed.