Wettability of NiAl, NiAlN, TiBC, and TiB–CN films by glass at high temperatures

The sticking/adhesion of glass to glass molding dies and forming tools is a critical problem which limits the quality of glass products and the performance and reliability of molding dies and forming tools. Depositing NiAl, NiAlN, TiBC, and TiBCN coatings and characterizing their wettability by glass at high temperature are part of an overall program that is being conducted to develop a non-sticking, oxidation resistant, and wear resistant coating system for glass molding dies and forming tools. The use of contact angle analysis for evaluation of wettability is described in this paper. The contact angles were measured by the sessile drop technique and analyzed by an image analyzer. The film microstructures were studied using cross-sectional TEM technique. Factors affecting the wettability are discussed. NiAl and NiAlN films seemed to offer more potential than TiBC and TiBCN films in terms of non-wettability by glass at high temperatures, they are promising ‘working’ layers for glass molding dies and forming tools.