Glass-to-metal seal formation of lithium tungstate. Due to its low thermal expansion coefficient, matched to glass, tungsten is frequently used for glass-metal bonds. Tungsten forms satisfying bonds with glasses with similar thermal expansion coefficient such as high-borosilicate glass. The surface of both the metal and glass should be smooth, without scratches. Tungsten has the lowest expansion coefficient of metals and the highest melting point. 304 Stainless steel forms bonds with glass via an intermediate layer of chromium(III) oxide and iron(III) oxide. Further reactions of chromium, forming chromium silicide dendrites, are possible. The thermal expansion coefficient of steel is however fairly different from
Pressure melting point flux from below and atmospheric warming or cooling from above. As the pressure increases with depth in a glacier from the weight of the ice above, the pressure melting point of ice decreases within bounds, as shown in the diagram. The level where ice can start melting is where the pressure melting point equals the actual temperature. In static equilibrium conditions, this would be the highest level where water can exist in a glacier. It would also be the level of the base of an ice shelf, or the ice-water interface of a subglacial lake. Pressure melting point The pressure