70% of the global rhenium production is used to make high-temperature alloy parts for jet engines. Another major application of rhenium is in platinum-rehenium catalyst, which can be used in the production of lead-free, high-octane gasoline.
alloy
The addition of rhenium will increase the creep strength of nickel high temperature alloy. Rhenium alloys typically contain 3 to 6 percent of rhenium. The second generation of the alloy contains 3% rhenium, which was used in the f-16 and f-15s engines. The third generation of monocrystalline alloys contains 6% of the rhenium, which was used in the f-22 and f-35 engines. The rhenium high temperature alloy is also used in industrial gas turbines. The high temperature alloy will form topological dense phase (TCP) after adding rhenium, so its microstructure will become unstable. The fourth and fifth generation of high-temperature alloys used ruthenium to avoid this phenomenon.
In 2006, the consumption of rhenium was: 28% for ge, 28% for Rolls-Royce, and 12% for pratt & Whitney, both for high-temperature alloys. Another 14 per cent were used as catalysts and 18 per cent for other purposes. As demand for military jet engines continues to increase, it is necessary to develop high-temperature alloys with lower rhenium levels to maintain supply. For example, the new type of CFM56 high-pressure turbine (HPT) leaves use a 1.5 percent rhenium alloy to replace the 3% rhenium.
Rhenium enhances the physical properties of tungsten. Tungsten - rhenium alloy is more pliable at low temperature, easy to manufacture and shape, and its stability is improved at high temperature. This change will increase with the content of rhenium, so the tungsten-rhenium alloy contains 27% of rhenium, which is the solubility limit of rhenium in tungsten. X - ray source is one of the applications of tungsten and rhenium alloys. The melting points and atomic weights of tungsten and rhenium are high, helping to withstand sustained electron impact. This alloy is also used as a thermocouple, can measure the highest temperature of 2200 ° C.
The rhenium is very stable at high temperature, the steam is low, wear resistant, and can resist the arc corrosion, so it is good to automatically clean the electric contact material. The electric spark from the switch will oxidize the contact. However, rhenium oxide (Re2O7) sublimates at 360 degrees C, so it will be removed during the discharge process.
Rhenium has the same high melting point and low vapor pressure as tantalum and tungsten, so the filament made of these materials has high stability in the oxygen environment. Such filaments are widely used in mass spectrometer, ionization gauge and photoflash.
catalyst
Rhenium is a catalyst in the catalytic reforming process. This process can increase the octane number of naphtha. Of the catalysts used for catalytic reforming, 30% contained rhenium. The surface of alumina (alumina) is coated with rhenium, which can be used as catalyst for the reaction of olefins. The catalysts containing rhenium can resist the poisoning of nitrogen, sulfur and phosphorus, and thus are used in some hydrogenation reactions.
