Pure tungsten
There are various types of tungsten materials. In order to enhance functionality or workability, additives are generally mixed. Pure tungsten without additives is introduced here.
1. Pure tungsten (Non-doped)
Pure tungsten wire spool. (Exhibited at Motoyama factory, Nippon Tungsten)
Overview
In general, if it has over 99.95% purity, we call it pure tungsten. We call it pure tungsten if additives are not included intentionally. Pure tungsten has lower recrystallization temperature, and it is relatively flexible compare to pottasium doped tungsten. As it is softer, it is also easier to machine, however thermal embrittlement could easily occur. At Takeishi, we use pure tungsten for electrodes for HID lamps, and parts for semiconductor products, which generally do not work well with additives like pottasium.
Depending on material supplier, content of pure tungsten varies from company to company.
Taking this into account, we offer the best available pure tungsten to our customers.
Examples using pure tungsten.
Electrodes for HID lamps, parts for semiconductor products are some of examples using pure tungsten.
Tungsten on tip of electrode for ceramic metal halide lamp
Material information available on other pages
2. Ultra high purity tungsten
Ultra pure tungsten recrystalization at 1600℃
5N tungsten treated at 1600℃ by hydrogen furnace.
Overview
Purity of 99.995 or higher (4NW), and purity of 99.9995 or higher (5NW) have much less impurity, compare to regular pure tungsten. It has less outgas when treated under heat. It is brittle as recrystalization temperature is considerably low. This material requires a lot of experience handling and processing.
Takeishi has been working with material supplier from development stage of these ultra pure tungsten materials. Depending on customers needs or product characteristics, we choose the best material that better suit to products.
Example of using ultra high purity tungsten
Ultra high purity tungsten is widely used for electrode for Ultra High Pressure mercury lamp
Electrode for Ultra High Pressure mercury lamp.