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 perfo rmance 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 resistan t coating system for glass molding dies and forming tools. The use of conta ct angle analysis for evaluation of wettability is described in this paper. The contact angles were measured by the sessile drop technique and analyze d by an image analyzer. The film microstructures were studied using cross-s ectional TEM technique. Factors affecting the wettability are discussed. Ni Al 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. (C) 2 000 Elsevier Science B.V. All rights reserved.