Tungsten foil - what is it and where is it applied?

Due to its unique properties, tungsten foil has become widespread. It is used in many spheres of life, from medicine to mechanical engineering, nuclear power engineering.

Properties

Despite the small thickness (only 0.03-0.09 mm), tungsten foil has amazing characteristics:

Heat resistance and heat resistance. Long service life even at temperatures up to 2500 degrees.

High coefficient of compression (tension).

Great value of electrical resistance.

Very low coefficient of thermal expansion.

High resistance to temperature creep.

Strength.

High value of the indicator of electronic emission.

Do not corrode.

Resistant to chemicals (acids, alkalis, royal vodka).

Biologically safe.

It is allowed to use in aggressive environments with high temperatures and high loads.

Along with many advantages, the material has its drawbacks:

Pure tungsten is difficult to obtain, since it is quite rare.

High specific gravity.

At low temperatures, the material becomes brittle.

Tungsten is a refractory and whimsical raw material, which is difficult to work with.

Production is possible only with the strongest heating of raw materials.

Due to the refractoriness, rarity of raw materials, difficulties in the course of its processing, the price of finished products is high.

Production

A tungsten foil made of pure metal is produced. Sheets are obtained by pressing the prepared stamps. After that, the metal is heated and forged at a temperature of 1500-1700 degrees.

For protection against oxidation, rolling is usedhot metal at high speed. When the thickness of the sheets reaches 0.6 mm, the rolling speed is reduced. The thinnest sheets are obtained by cold rolling. To smooth the surface of the foil, run-in is used.

To remove the oxidation spots, use a heated sodium solution. Next, the sheet is calcined in the presence of hydrogen at a temperature of 1000 degrees.