Editing Molybdenum (section)

===Alloys===
[[File:Plate of Molybdenum Copper .jpg|thumb|A plate of molybdenum copper alloy]]
About 86% of molybdenum produced is used in [[metallurgy]], with the rest used in chemical applications. The estimated global use is [[structural steel]] 35%, [[stainless steel]] 25%, chemicals 14%, tool & high-speed steels 9%, [[cast iron]] 6%, molybdenum elemental metal 6%, and [[superalloy]]s 5%.<ref>{{cite web |url=http://www.lme.com/minormetals/6782.asp |archive-url=https://web.archive.org/web/20120310004452/http://www.lme.com/minormetals/6782.asp |archive-date=2012-03-10 |title=Molybdenum |work=Industry usage |publisher=London Metal Exchange}}</ref>

Molybdenum can withstand extreme temperatures without significantly expanding or softening, making it useful in environments of intense heat, including military armor, aircraft parts, electrical contacts, industrial motors, and supports for filaments in [[light bulbs]].<ref name="nbb" /><ref name="azom" />

Most high-strength steel [[alloy]]s (for example, [[41xx steel]]s) contain 0.25% to 8% molybdenum.<ref name="CRCdescription2" /> Even in these small portions, more than 43,000 tonnes of molybdenum are used each year in [[stainless steel]]s, [[tool steel]]s, cast irons, and high-temperature [[superalloy]]s.<ref name="Nostrand" />

Molybdenum is also used in steel alloys for its high [[corrosion]] resistance and [[weldability]].<ref name="Nostrand" /><ref name="USGS">{{cite web|title = Molybdenum Statistics and Information|publisher = U.S. Geological Survey|date = 2007-05-10|url = http://minerals.usgs.gov/minerals/pubs/commodity/molybdenum/|access-date = 2007-05-10|archive-url = https://web.archive.org/web/20070519151353/http://minerals.usgs.gov/minerals/pubs/commodity/molybdenum/|archive-date = 2007-05-19|url-status = live}}</ref> Molybdenum contributes corrosion resistance to [[SAE steel grades#300 Series—austenitic chromium-nickel alloys|type-300 stainless steels]] (specifically [[316 stainless steel|type-316]]) and especially so in the so-called [[Austenitic|superaustenitic]] stainless steels (such as alloy [[AL-6XN]], 254SMO and 1925hMo). Molybdenum increases lattice strain, thus increasing the energy required to dissolve iron atoms from the surface.{{contradictory inline|date=September 2018}} Molybdenum is also used to enhance the corrosion resistance of ferritic (for example grade 444)<ref>(2023) Stainless Steel Grades and Properties. International Molybdenum Association. https://www.imoa.info/molybdenum-uses/molybdenum-grade-stainless-steels/steel-grades.php?m=1683978651&</ref> and martensitic (for example 1.4122 and 1.4418) stainless steels.{{citation needed|date=December 2014}}

Because of its lower density and more stable price, molybdenum is sometimes used in place of tungsten.<ref name="Nostrand" /> An example is the 'M' series of high-speed steels such as M2, M4 and M42 as substitution for the 'T' steel series, which contain tungsten. Molybdenum can also be used as a flame-resistant coating for other metals. Although its melting point is {{convert|2623|°C|°F|abbr=on}}, molybdenum rapidly oxidizes at temperatures above {{convert|760|°C|°F|abbr=on}} making it better-suited for use in vacuum environments.<ref name="azom">{{cite web|title=Molybdenum|publisher=AZoM.com Pty. Limited|date=2007|url=http://www.azom.com/article.aspx?ArticleID=616|access-date=2007-05-06|archive-url=https://web.archive.org/web/20110614171110/http://www.azom.com/article.aspx?ArticleID=616|archive-date=2011-06-14|url-status=dead}}</ref>

TZM (Mo (~99%), Ti (~0.5%), Zr (~0.08%) and some C) is a corrosion-resisting molybdenum superalloy that resists molten fluoride salts at temperatures above {{convert|1300|°C|°F|abbr=on}}. It has about twice the strength of pure Mo, and is more ductile and more weldable, yet in tests it resisted corrosion of a standard eutectic salt ([[FLiBe]]) and salt vapors used in [[molten salt reactor]]s for 1100 hours with so little corrosion that it was difficult to measure.<ref>{{cite book|last=Smallwood|first=Robert E.|title=ASTM special technical publication 849: Refractory metals and their industrial applications: a symposium|chapter-url=https://books.google.com/books?id=agaacIr25KcC&pg=PA9|date=1984|publisher=ASTM International|isbn=978-0803102033|page=9|chapter=TZM Moly Alloy}}</ref><ref>{{cite web|url = http://www.energyfromthorium.com/forum/download/file.php?id=805|title = Compatibility of Molybdenum-Base Alloy TZM, with LiF-BeF<sub>2</sub>-ThF<sub>4</sub>-UF<sub>4</sub>|publisher = Oak Ridge National Laboratory Report|access-date = 2010-09-02|date = December 1969|archive-url = https://web.archive.org/web/20110710192254/http://www.energyfromthorium.com/forum/download/file.php?id=805|archive-date = 2011-07-10|url-status = dead}}</ref> Due to its excellent mechanical properties under high temperature and high pressure, TZM alloys are extensively applied in the military industry.<ref>{{cite web |url=https://apps.dtic.mil/sti/pdfs/AD0618935.pdf |title=A protective coating system for a TZM alloy re-entry vehicle |website=US Army |last=Levy |first=M. |date=1965 |access-date=June 3, 2024}}</ref> It is used as the valve body of [[torpedo]] engines, [[Rocket engine nozzle|rocket nozzles]] and gas pipelines, where it can withstand extreme thermal and mechanical stresses.<ref>{{cite journal |last1=Yang |first1=Zhi |last2=Hu |first2=Ke |date=2018 |title=Diffusion bonding between TZM alloy and WRe alloy by spark plasma sintering |journal=Journal of Alloys and Compounds |volume=764 |pages=582–590 |doi=10.1016/j.jallcom.2018.06.111}}</ref><ref>{{cite patent |country=CN |status=patent |number=109590476B}}</ref>  It is also used as [[radiation]] shields in nuclear applications.<ref>{{cite web |url=https://www.samaterials.com/content/preparation-application-of-tzm-alloy.html |title=Preparation & Application of TZM Alloy |last=Trento |first=Chin |website=Stanford Advanced Materials |date=Dec 27, 2023 |access-date=June 3, 2024}}</ref>

Other molybdenum-based alloys that do not contain iron have only limited applications. For example, because of its resistance to molten zinc, both pure molybdenum and molybdenum-[[tungsten]] alloys (70%/30%) are used for piping, stirrers and pump impellers that come into contact with molten zinc.<ref>{{cite book|title =Tool and manufacturing engineers handbook|first = W. H.|last = Cubberly|author2=Bakerjian, Ramon|publisher = Society of Manufacturing Engineers|isbn = 978-0-87263-351-3|url = https://books.google.com/books?id=NRXnXmFRjWYC&pg=PT421|page = 421|date =1989}}</ref>