Products from tungsten differ in high durability therefore it finds broad application in rocket production, the electrolamp and radio engineering industry. Metal is applied as in pure form, and in the form of alloys. The fragility and refractoriness of tungsten do its processing rather labor-consuming. Therefore apply various cunnings to soldering of this metal.
Instruction
1. You make soldering of tungsten at a temperature below temperature of its recrystallization which is 1450 degrees. Above the specified temperature durability of metal decreases. Give in to soldering of a product from tungsten in combination with the same metal more simply; its connection with other materials is complicated because of a difference in coefficients of linear expansion.
2. Before soldering carefully clean a surface of tungsten products with mechanical means or way of etching in hydrofluoric or nitric acid. In the absence of acid use hot solution of a caustic natr. Wipe the purified metal with alcohol or wash with hot water.
3. For obtaining the maximum purity and density of a seam conduct soldering in a vacuum. Both other protective and recovery environments will approach, but at the same time it is required to cover previously tungsten with nickel or copper by a galvanic method; it will improve metal wetting by the melted solder.
4. For high-temperature melting of tungsten use copper, nickel or gold and also their alloys as solder. You make soldering at the maximum speeds of heating with the maximum endurance when soldering.
5. If conditions allow, apply the most perspective way of soldering of tungsten which consists in its combination to diffusive processing. At the same time there are a diffusion, dissolution and evaporation of separate components of fusion. Diffusive soldering does a seam to less fragile and reduces solder thickness in a gap.
6. For capillary soldering of tungsten in a vacuum or argon use solders on the basis of silver, nickel or iron in a powdery look. The connections of tungsten products executed by means of soldering by pure iron can reliably work at a temperature of 900 degrees. Special attention here too should be paid to high-quality preparation of a surface and removal of oxides from it.