Some recent studies on glass/glass-ceramics for use as sealants with special emphasis for high temperature applications

Glass-ceramics owing to a combination of useful properties such as tuneable thermal expansion coefficient (TEC), good mechanical durability and chemical inertness find widespread uses in a variety of applications including seals and coatings. Glass-ceramic-to-metal seals have been fabricated with various silicate, phosphate and borate based oxide glasses depending upon the intended application. In this article, we review our studies on various glass and glass-ceramics materials development with a view to understand bonding behaviour with metals/alloys at ambient and high temperatures through a comprehensive structure property correlation investigations. Detail studies on BaO-CaO-Al2O3-B2O3-SiO2 (BCABS), barium strontium alumino-silicate, and strontium alumino-silicate with different additives (like Nd2O3, La2O3, NiO, TiO2, V2O5, ZrO2, Cr2O3, and P2O5) and barium/strontiun zinc silicate (B/SZS) glass-ceramics for high temperature sealing. We shall illustrate the role of various thermo-physical and structural characterization techniques that allowed optimum selection of materials and processing parameters. We particularly highlight the complementary role of NMR and XRD in studying the material at the short range and long range length scales.