Although tungsten has a higher melting point than rhenium, tungsten alloys are also more difficult to process, more brittle at high temperatures, and more easily oxidized. Rhenium alloys are easier to process and have excellent creep resistance and oxidation resistance at high temperatures, making it an important metal for aerospace applications, especially in high-temperature parts of jet engines. But the biggest problem with rhenium is that it is rare and has low annual production.
Can see, the density of metal rhenium is higher than tungsten, melting point is lower than tungsten about 200 degrees, massive rhenium metal is silvery white, its atomic arrangement shows hexagonal close row crystal structure, chemical property is very stable, have very strong acid resistance, below normal temperature even aqua regal also can not be dissolved. Rhenium is an element discovered in 1925, is also the last stable element to be discovered, 2014 data, the global proven resources of rhenium is about 2,500 tons, only one percent of gold, can be said to be quite rare.
Alloys with rhenium (the content is generally 3%~6%) have good creep resistance and oxidation resistance, and can withstand high temperatures above 1500℃. They are excellent high temperature materials in the field of aerospace, such as single-crystal turbine blades of aero-engines, rocket nozzles, etc. At present, no superior high temperature materials than rhenium alloy have been found.
Early space high temperature material also use tungsten alloy, but the disadvantage of tungsten is very obvious, first of all, tungsten brittle, processing difficulties, oxidation resistance is not good, tungsten is slow oxidation during temperature higher than 1000 ℃, this will reduce the life of the aerospace engines, and join the rhenium alloy is maintained a very good high temperature performance, so for aeroengine blades, metal rhenium than metal tungsten is excellent.
