There are two ways to make tungsten-rhenium alloy: powder metallurgy and smelting, and powder metallurgy is commonly used in actual production. The powder metallurgy process for producing tungsten-rhenium alloys is as follows:
Preparation of tungsten-rhenium pre-alloying powder → hydrogen reduction → pressing (mold pressing or isostatic pressing)→ sintering (vertical melting sintering or medium frequency induction sintering)→ pressure processing (including extrusion, rolling, rotary forging and wire drawing).
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.
Hydrogen reduced tungsten-rhenium alloy powder can be formed by mechanical pressing, steel die pressing, or isostatic pressing (even density of compaction). The compacted bars can be directly fired by vertical melting or by Cp,N induction by indirect heating. The relative density of tungsten-rhenium alloy bars is 92% ~ 95%. The best quality billet can be obtained by isostatic pressing and medium frequency induction heating sintering, and its uniformity and consistency are the best among all production methods. Tungsten-rhenium alloy is mainly used as structural material in high temperature field, and has a wide range of applications in electronic technology, nuclear technology, aerospace technology and temperature measurement technology.
At present, the most widely used in three aspects:
1. Low - rhenium alloy wire and high - rhenium alloy wire matching into thermocouple.
2. Low rhenium alloy wire and high rhenium alloy wire match into a thermocouple, wide temperature range (0 ~ 2500C), high thermoelectric potential value, fast response speed, good corrosion resistance, so tungsten-rhenium thermocouple wire is widely used in temperature measuring instruments. It is not only used in vacuum, reducing atmosphere and inert atmosphere, but also used to replace platinum rhodium thermocouple temperature measurement in oxidizing atmosphere when taking anti-oxidation measures to get practical applications.
3. Used for manufacturing single crystal sapphire and binding.
