Analysis of tungsten heater
As a typical representative of refractory metal tungsten products, tungsten heater is a product made of pure tungsten wire or doped tungsten wire through deep processing. The English name is tungsten heater. The tungsten content is generally greater than 99.95%, and the diameter range is 0.2-1.2mm.
From the perspective of physical and chemical properties, tungsten heaters are generally characterized by high melting point, high specific gravity, high strength, large hardness, large resistivity, low vapor pressure, low evaporation rate, small thermal expansion coefficient, high temperature resistance, wear resistance, impact resistance, corrosion resistance, and good electrical and thermal conductivity. Note: The tungsten heater made of doped tungsten wire has higher comprehensive performance than the product made of doped tungsten wire, mainly manifested in less brittleness and better processing performance.
From the perspective of production method, the production process of tungsten heater is as follows: ammonium paratungstate is calcined to make blue tungsten, blue tungsten is doped with ingredients, mixed into doped blue tungsten, and then reduced to doped tungsten powder. Finally, it goes through such processes as pressing, sintering, rotary forging, annealing, wire drawing, wire burning, etc.
From the perspective of application, tungsten heater is often used as the material of evaporation source of vacuum evaporation plating machine, mainly used to produce computers, picture tubes, mirrors, plastics, lamps, mobile phone shells, precision optics, process glass, cosmetic packaging and photovoltaic product coating.
Doped tungsten wire, also known as 218 tungsten wire or non drooping tungsten wire, refers to the product with appropriate amount of potassium oxide, silicon oxide and aluminum oxide added in the production process of pure tungsten wire.
The advantages of using tungsten heater in vacuum evaporation plating machine include high utilization rate of tungsten resources and good coating effect, that is, the film products have high precision, uniformity and stability, mainly due to the high melting point, good corrosion resistance and oxidation resistance of the heater.
