Seismic Tungsten-rhenium Wire Production

Tungsten wire in the field of lighting systems are the most widely used, but to be applied to aircraft, ships and cars lights and other special lighting systems and as high precision gas chromatograph thermal conductivity wire, kinescope wire, UHF tube filament and thermocouple wire need to produce tungsten wire with more favorable properties. The experiment found that tungsten powder further doping rhenium on the basis of doped K, Si, and Al to produce tungsten-rhenium wire has good performance. Tungsten-rhenium wire not only maintain a high temperature sag resistance and improved tungsten room temperature shaping process, thereby improving the seismic performance of the tungsten wire.

Rhenium is a rare metal. At room temperature, it is grayed and crystal structure is sixty thousand close-packed. Its physical properties are as follows: Density: 21.04g / cm3; Melting point: 3180 ℃, the melting point of rhenium only lower than tungsten; boiling point: 5627 ℃; insoluble in hydrochloric acid and hydrofluoric acid. Rhenium is kind of ductility metal at room temperature which is easily formed into a sheet or wire, and the more purity of rhenium the easier molding process. But as the temperature rises rhenium will occurs work hardening in varying degrees, making it difficult to process deformation at high temperature. Therefore, as the additive element adding in tungsten wire can improve the high temperature sag resistance and shaping process at room temperature.

Tungsten-rhenium wire production processes:
1. Adding Si, Al, K and ammonium perrhenate (NH4Re4O) solution into tungsten trioxide (WO3), then after evaporation, drying, sieving, hydrogen reduction and other processes produce rhenium tungsten mixed powder. The doping mode will chose wet doping, because the wet doping can make more uniform distribution of rhenium in the tungsten-based. At the same time compared the effects of different content of rhenium doped on tungsten found rhenium added in an amount of 3% can produce more favorable performance tungsten-rhenium wire.
2. The mixed powder is pressed into a tungsten-rhenium strip, obtained billet after through sintered.
3. Finally, after swaging, drawing and other processes produce tungsten-rhenium wire.

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