Preparation & Characterization of h-BN Coatings on Ti-Based Substrate Synthesized via the PDCs Route: Tribological Applications in Severe Conditions

Abstract

H-BN coatings can be achieved by the Polymer Derived Ceramics (PDCs) route on metallic substrate, i.e. titanium. The ceramization process is led via an optical treatment by IR irradiation to overcome the problem of the metal stability at high temperature (needed in classical process). Structural and chemical characterisations by XRD, IR, RAMAN and EDS show that the obtained crackless coatings have a micro composite structure composed by a µ-layer of TiBx/TiN at the interphase, the h-BN coating and a layer of BN(O) at the surface. Hereafter, tribological and mechanical analyses investigated through nano- and micro-indentation give a weak friction coefficient and show a good adherence between the substrate and the coating. This good adherence can be explained by the formation of Ti-B-N bond at the interface.