Editing Rhenium (section)

===Alloys===
The nickel-based [[superalloy]]s have improved [[Creep (deformation)|creep strength]] with the addition of rhenium. The alloys normally contain 3% or 6% of rhenium.<ref>{{cite web|title=Nickel Based Superalloys|first=H. K. D. H.|last=Bhadeshia|url=http://www.msm.cam.ac.uk/phase-trans/2003/Superalloys/superalloys.html|publisher=University of Cambridge|access-date=2008-10-17|url-status=dead|archive-url=https://web.archive.org/web/20060825053006/http://www.msm.cam.ac.uk/phase-trans/2003/Superalloys/superalloys.html|archive-date=2006-08-25}}</ref> Second-generation alloys contain 3%; these alloys were used in the engines for the [[Pratt & Whitney F100|F-15 and F-16]], whereas the newer single-crystal third-generation alloys contain 6% of rhenium; they are used in the [[Pratt & Whitney F119|F-22]] and [[Pratt & Whitney F135|F-35]] engines.<ref name="USGS_2009_yearbook" /><ref>{{cite book |title=Aerospace Materials: An Oxford-Kobe Materials Text|first=B.|last=Cantor|author2=Grant, Patrick Assender Hazel |publisher=CRC Press| date=2001|isbn=978-0-7503-0742-0|url=https://books.google.com/books?id=n09-HajhRHYC |pages=82–83}}</ref> Rhenium is also used in the superalloys, such as CMSX-4 (2nd gen) and CMSX-10 (3rd gen) that are used in industrial [[gas turbine]] engines like the GE 7FA. Rhenium can cause [[superalloy]]s to become microstructurally unstable, forming undesirable topologically close packed (TCP) [[phase (matter)|phases]]. In 4th- and 5th-generation [[superalloy]]s, [[ruthenium]] is used to avoid this effect. Among others the new [[superalloy]]s are EPM-102 (with 3% Ru) and TMS-162 (with 6% Ru),<ref>{{cite journal|doi = 10.1007/s11041-006-0099-6|title = Effect of high-gradient directed crystallization on the structure and properties of rhenium-bearing single-crystal alloy|date = 2006|author = Bondarenko, Yu. A.|journal = Metal Science and Heat Treatment|volume = 48|page = 360|last2 = Kablov|first2 = E. N.|last3 = Surova|first3 = V. A.|last4 = Echin|first4 = A. B.|issue = 7–8|bibcode = 2006MSHT...48..360B|s2cid = 136907279}}</ref> as well as TMS-138<ref>{{cite news| title=Fourth generation nickel base single crystal superalloy|url=http://sakimori.nims.go.jp/catalog/TMS-138-A.pdf}}</ref> and TMS-174.<ref>{{cite journal|author=Koizumi, Yutaka|display-authors=etal|title= Development of a Next-Generation Ni-base Single Crystal Superalloy|url=http://nippon.zaidan.info/seikabutsu/2003/00916/pdf/igtc2003tokyo_ts119.pdf|journal=Proceedings of the International Gas Turbine Congress, Tokyo November 2–7, 2003}}</ref><ref>{{cite news| title=Joint Development of a Fourth Generation Single Crystal Superalloy|author=Walston, S.|author2=Cetel, A.|author3=MacKay, R.|author4=O'Hara, K.|author5=Duhl, D.|author6=Dreshfield, R.|url=http://gltrs.grc.nasa.gov/reports/2004/TM-2004-213062.pdf| url-status=dead|archive-url=https://web.archive.org/web/20061015113650/http://gltrs.grc.nasa.gov/reports/2004/TM-2004-213062.pdf |archive-date=2006-10-15}}</ref>

[[File:CFM56 P1220759.jpg|thumb|left|CFM International CFM56 jet engine with blades made with 3% rhenium]]

For 2006, the consumption is given as 28% for [[General Electric]], 28% [[Rolls-Royce plc]] and 12% [[Pratt & Whitney]], all for superalloys, whereas the use for catalysts only accounts for 14% and the remaining applications use 18%.<ref name="Naumov" /> In 2006, 77% of rhenium consumption in the United States was in alloys.<ref name="USGS_2009_yearbook" /> The rising demand for military jet engines and the constant supply made it necessary to develop superalloys with a lower rhenium content. For example, the newer [[CFM International CFM56]] high-pressure turbine (HPT) blades will use Rene N515 with a rhenium content of 1.5% instead of Rene N5 with 3%.<ref>{{cite journal | last1 = Fink | first1 = Paul J. | last2 = Miller | first2 = Joshua L. | last3 = Konitzer | first3 = Douglas G. | title = Rhenium reduction—alloy design using an economically strategic element | journal = JOM | volume = 62 | issue = 1 | page = 55 | date = 2010 | doi = 10.1007/s11837-010-0012-z|bibcode = 2010JOM....62a..55F | s2cid = 137007996 }}</ref><ref>{{cite web| first =Douglas G. | last =Konitzer | url = http://memagazine.asme.org/Articles/2010/September/Design_Era_Constrained.cfm | archive-url = https://web.archive.org/web/20110725021809/http://memagazine.asme.org/Articles/2010/September/Design_Era_Constrained.cfm | archive-date = 2011-07-25 | title = Design in an Era of Constrained Resources | access-date = 2010-10-12| date = September 2010}}</ref>

Rhenium improves the properties of [[tungsten]]. Tungsten-rhenium alloys are more ductile at low temperature, allowing them to be more easily machined. The high-temperature stability is also improved. The effect increases with the rhenium concentration, and therefore tungsten alloys are produced with up to 27% of Re, which is the solubility limit.<ref>{{cite book|title=Tungsten: properties, chemistry, technology of the element, alloys, and chemical compounds|first=Erik|last=Lassner|author2=Schubert, Wolf-Dieter | publisher=Springer|date=1999|isbn=978-0-306-45053-2|url=https://books.google.com/books?id=foLRISkt9gcC&pg=PA256|page=256}}</ref> Tungsten-rhenium wire was originally created in efforts to develop a wire that was more ductile after recrystallization. This allows the wire to meet specific performance objectives, including superior vibration resistance, improved ductility, and higher resistivity.<ref>{{Cite news|url=http://ucfilament.com/materials/tungsten-rhenium/|title=Tungsten-Rhenium - Union City Filament|work=Union City Filament|access-date=2017-04-05|language=en-US}}</ref> One application for the tungsten-rhenium alloys is [[X-ray]] sources. The high melting point of both elements, together with their high atomic mass, makes them stable against the prolonged electron impact.<ref>{{cite book|title =Practical radiotherapy physics and equipment|first=Pam|last=Cherry|author2=Duxbury, Angela |publisher=Cambridge University Press|date=1998|isbn=978-1-900151-06-1|url =https://books.google.com/books?id=5WIBbmmDm-gC&pg=PA55|page=55}}</ref> Rhenium tungsten alloys are also applied as [[thermocouple]]s to measure temperatures up to 2200 °[[Celsius|C]].<ref>{{cite journal |title=Tungsten-Rhenium Thermocouples for Use at High Temperatures|journal=Review of Scientific Instruments|volume=39|page=1233|date=1968|doi=10.1063/1.1683642|first= R.|last=Asamoto|author2=Novak, P. E. |issue=8|bibcode = 1968RScI...39.1233A }}</ref>

The high temperature stability, low vapor pressure, good [[Wear|wear resistance]] and ability to withstand arc corrosion of rhenium are useful in self-cleaning [[Switch#Contacts|electrical contacts]]. In particular, the discharge that occurs during electrical switching oxidizes the contacts. However, rhenium oxide Re<sub>2</sub>O<sub>7</sub> is volatile (sublimes at ~360&nbsp;°C) and therefore is removed during the discharge.<ref name="Naumov" />

Rhenium has a high melting point and a low vapor pressure similar to [[tantalum]] and tungsten. Therefore, rhenium filaments exhibit a higher stability if the filament is operated not in vacuum, but in oxygen-containing atmosphere.<ref>{{cite journal|doi=10.1021/j100873a513|date=1966|last=Blackburn|first=Paul E.|journal=The Journal of Physical Chemistry|volume=70|pages=311–312|title=The Vapor Pressure of Rhenium}}</ref> Those filaments are widely used in [[mass spectrometer]]s, [[ion gauge]]s<ref>{{cite journal|title=Tungsten-Rhenium Filament Lifetime Variability in Low Pressure Oxygen Environments|last= Earle|first=G. D.|author2=Medikonduri, R. |author3=Rajagopal, N. |author4=Narayanan, V. |author5= Roddy, P. A. |journal= IEEE Transactions on Plasma Science|volume=33|issue=5|pages=1736–1737|doi =10.1109/TPS.2005.856413|date=2005|bibcode = 2005ITPS...33.1736E |s2cid= 26162679}}</ref> and [[photoflash]] lamps in [[photography]].<ref>{{cite book|title=The chemical element: a historical perspective|first=Andrew|last=Ede| publisher=Greenwood Publishing Group|date=2006|isbn=978-0-313-33304-0}}</ref>