Views: 3 Author: Site Editor Publish Time: 2022-08-15 Origin: Site
Like the evaporation tungsten boat, the tungsten crucible is also a typical product of the refractory metal tungsten. It is a product with metal tungsten powder as the main raw material. It is a high temperature resistant vessel. Above 99.95%, the shape is generally cylindrical, the diameter is between 10mm and 500mm, the height is between 10mm and 750mm, and the wall thickness is between 8mm and 20mm.
In terms of physical and chemical properties, the characteristics of tungsten crucibles include high specific gravity, high melting point, high boiling point, low vapor pressure, small evaporation rate, low thermal expansion coefficient, corrosion resistance, wear resistance, and good thermal conductivity. Note: According to the different production processes, tungsten crucibles can be divided into forging molding, sintering molding, welding molding, stamping molding, spinning molding, etc., in which the density of forging molding and sintering molding is greater than 19.35g/cm3 and 18.5g/cm3 respectively; Adding a certain amount of rare earth elements during the manufacture of pure tungsten crucibles can improve the oxidation resistance of the crucibles, thereby prolonging the service life of the products.
In terms of production method, the preparation steps of tungsten crucible include batch mixing, isostatic pressing, shaping, sintering and finishing. Four different tungsten powders with particle size in the range of 1.0~5.0um are used for ingredients; the isostatic pressing pressure is about 200MPa, and the holding time is about 7 minutes; the sintering temperature is about 2300°C, and the sintering time is about 7 hours.