A alloy wire composed of tungsten and rhenium. Tungsten-rhenium wire has the advantages of high strength at room temperature and high temperature, good plasticity after recrystallization, high resistivity, low resistivity, anti-oxidation and carbonization, strong resistance to "water cycle reaction" and good welding performance. Used for color picture tube hot wire, various tube filament and gate.
The alloys contain rhenium 1% to 5% (mass) and are also doped with silicon, aluminum, and potassium to improve the high temperature properties of the materials. Tungsten-rhenium wire in addition, 25%Re and 26%Re two commonly used tungsten-rhenium alloy, mainly used as thermocouple material! The main advantages of tungsten-rhenium thermocouple are: 1, the response speed is fast. 2. The temperature measurement range is wide, up to 2500℃. However, it is generally used in inert atmosphere or reducing atmosphere, otherwise it is necessary to add protection sleeve, which is generally M, o alloy sleeve. Wolframe-rhenium wire has three grades: wal-mart re, wal-mart 3Re and wal-mart 5Re.
Tungsten is often impregnated with microcracks at grain boundaries. The growth of these microcracks is an important cause of tungsten fracture. Twinning is easily formed in the process of deformation of tungsten-rhenium alloy, so the dislocation energy of the stacking layer is reduced, the grain boundary impedance of dislocation movement is reduced, and the dislocation mobility is increased. This phenomenon is known as the rhenium plasticizing effect. In the series of tungsten-rhenium alloys, the plasticizing effect of rhenium was obvious when rhenium concentration was low, and decreased when rhenium concentration was high.
For making tungsten rhenium pre alloy powder is a commonly used method of fixation (tungsten powder mixed with rhenium powder, tungsten trioxide powder mixed with rhenium acid ammonium powder), solid a liquid method (mixed with ammonium nitrate solution rhenium tungsten powder, tungsten trioxide powder mixed with rhenium acid ammonium solution), a liquid (ammonium tungstate solution mixed with rhenium acid ammonium solution by spray drying or other methods for making), etc.
