Rapid thermal annealing of Cr–Si–N, Ta–Si–N, and Zr–Si–N coatings in glass molding atmospheres

Abstract

Glass molding is widely used for manufacturing high-precision optical elements. Nitride coatings are recommended as protective coatings on glass molding dies. In a die-fixed glass molding system, the molding dies undergo rapid thermal shocks. In this study, near-amorphous Cr–Si–N, Ta–Si–N, and Zr–Si–N coatings with a Si concentration of >14 at.% were prepared. The feasibility of these coatings in the glass molding process was evaluated through rapid thermal cycling annealing in a 15-ppm O2–N2 atmosphere. The cycling annealing test was performed at 270 °C and 580 °C or 600 °C. The heating, holding, and cooling times in the annealing process were 1 min each. The results indicated that Zr–Si–N coatings exhibited superior anti-sticking against SiO2–B2O3–BaO-based glass. The reactions between the nitride coatings and glass were investigated.