Microstructure and Properties of Protective Ion-Plasma Coating on UFG Ti Alloy

The paper presents results of comprehensive studies on a fine structure of TiVN ion-plasma protective coating deposited on a Ti–6Al–4V substrate with an ultrafine-grained (UFG) structure. This coating considerably improves the performance properties of critical products operating under high loads in aggressive environments. In the article special attention is paid to features of formation of coating layers and their phase composition with account of effect caused the substrate ultrafine-grained structure. It is established that TiVN functional coating has a layered structure with thin layers of dark and light colors, which can be formed at different ratios of Ti and V concentrations due to planetary rotation of substrates. The structure of a TiVN functional layer is columnar and has an average diameter of about 17 nm. Based on microdiffraction patterns of a TiVN layer, it is found that the reflexes correspond to an fcc structure, which does not have a dominant textural component of growth. This might be conditioned by high level of ion activation of growth and multicomponent nature of the coating being terms for creation and retention of high density of defects. This fine structure of ion-plasma coating on a substrate with UFG structure provides the achievement of high adhesion and erosion resistance.