Tungsten Property for Sapphire Growth Furnace

Tungsten is an important material to be used in sapphire growth furnace. The products of tungsten used in sapphire growth furnace is using tungsten with the purity over 99.95%. The tungsten for sapphire growth furnace composed of tungsten crucible, tungsten plates, tungsten sheet, tungsten electrode screen, tungsten barrel, and tungsten heater. In addition to the pure tungsten products, tungsten-rhenium wire is necessary for sapphire crystal growth furnace, which is normally used 25% tungsten rhenium wire.

Tungsten is used as the sapphire growth furnace material whose purity is over 99.95%. Pure tungsten products are preferred by the customers of its high density, high temperature resistance, high corrosion resistance, high wear resistance, high hardness, low coefficient of thermal expansion. These properties are also the reasons for sapphire growth furnace chooses tungsten as its main material. The property of high temperature resistance will not decompose tungsten with the crystal atoms, so they can ensure the purity of crystal without much impurities.

Tungsten crucible used in the sapphire growth furnace is using the manufacturing technique of sintering. Generally speaking, the densith of sintering tungsten, such as tungsten crucibke is about 18.2g/cm3. During the process of sintering, the property of tungsten can not be changed.

molybdenum-crucible

Tungsten is a silver-white metal, which is similar to steel. Tungsten owns the properties of high melting point, low vapor pressure, and evaporation rate . The chemical properties of tungsten is very stable at room temperature without reaction with air and water, not heated, any concentration of hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid and aqua regia tungsten does not work, when the temperature rose to 80 ° -100 ° C, the above-mentioned acid addition to hydrofluoric acid, other acids of tungsten weak role. Room temperature, the tungsten can be quickly dissolved in the mixed acid of hydrofluoric acid and concentrated nitric acid, but does not work in the alkali solution. Air conditions, the molten alkali tungsten oxide into the tungstate in the presence of oxidants (NaNO3, NaNO2, potassium chlorate, PbO2 by) generated tungstate reaction is more violent. High temperature with chlorine, bromine, iodine, carbon, nitrogen, sulfur compounds, but not with the hydride.