Glass casting a French commercial crystal manufacturer, produce highly sculptural pieces in pate de verre. Graphite is also used in the hot forming of glass. Graphite moulds are prepared by carving into them, machining them into curved forms, or stacking them into shapes. Molten glass is poured into a mould where it is cooled until hard enough to be removed and placed into an annealing kiln to cool slowly. Glass casting Glass casting is the process in which glass objects are cast by directing molten glass into a mould where it solidifies. The technique has been used since the Egyptian period. Modern
Glass-ceramic-to-metal seals of S.A. Claypoole considers glass-ceramic-to-metal seals as well. Glass-ceramic-to-metal seals Glass-to-metal seals have been around for many years, with one of the most common uses being lamp bulb seals. A more recent invention is glass-ceramic-to-metal seals. "Glass-ceramics" are polycrystalline ceramic materials prepared by the controlled crystallization of suitable glasses, normally silicates. Depending on the starting glass composition and the heat-treatment schedule adopted, glass-ceramics can be prepared with tailored thermal expansion characteristics. This makes them ideal for sealing to a variety of different metals, ranging from low expansion tungsten (W) or molybdenum (Mo) to high expansion stainless steels and nickel-based superalloys.