Editing Molybdenum (section)

==Applications==

===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>

===Pure element applications===
* Molybdenum powder is used as a fertilizer for some plants, such as [[cauliflower]].<ref name="Nostrand" />
* Elemental molybdenum is used in NO, NO<sub>2</sub>, NO<sub>x</sub> analyzers in power plants for pollution controls. At {{convert|350|°C|°F|abbr=on}}, the element acts as a catalyst for NO<sub>2</sub>/NO<sub>x</sub> to form NO molecules for detection by infrared light.<ref>{{cite journal|doi = 10.1023/A:1010730821844|date = 2001|last1= Lal|first1 = S.|last2 = Patil|first2 = R. S.|s2cid = 20441999|journal = Environmental Monitoring and Assessment|volume = 68|pages= 37–50|pmid = 11336410|title = Monitoring of atmospheric behaviour of NO<sub>x</sub> from vehicular traffic|issue = 1| bibcode=2001EMnAs..68...37L }}</ref>
* Molybdenum anodes replace tungsten in certain low voltage X-ray sources for specialized uses such as [[mammography]].<ref>{{cite book|title=Physics of Medical X-Ray Imaging|chapter-url=http://ric.uthscsa.edu/personalpages/lancaster/DI-II_Chapters/DI_chap4.pdf|chapter=Ch. 4: Physical determinants of contrast|author=Lancaster, Jack L.|publisher=University of Texas Health Science Center|url-status=dead|archive-url=https://web.archive.org/web/20151010172937/http://ric.uthscsa.edu/personalpages/lancaster/DI-II_Chapters/DI_chap4.pdf|archive-date=2015-10-10}}</ref>
* The radioactive isotope [[molybdenum-99]] is used to generate [[technetium-99m]], used for medical imaging<ref>[[Theodore Gray|Gray, Theodore]] (2009). ''The Elements''. Black Dog & Leventhal. pp. 105–107. {{ISBN|1-57912-814-9}}.</ref> The isotope is handled and stored as the molybdate.<ref>{{cite journal|doi = 10.1146/annurev.me.20.020169.001023|pmid = 4894500|date = 1969|last1 = Gottschalk|first1 = A.|title = Technetium-99m in clinical nuclear medicine|volume = 20|pages = 131–40|journal = Annual Review of Medicine|issue=1}}</ref>

===Compound applications===
* [[Molybdenum disulfide]] (MoS<sub>2</sub>) is used as a solid [[lubricant]] and a high-pressure high-temperature (HPHT) anti-wear agent. It forms strong films on metallic surfaces and is a common additive to HPHT greases — in the event of a catastrophic grease failure, a thin layer of molybdenum prevents contact of the lubricated parts.<ref>{{cite journal|doi =10.1016/0043-1648(67)90187-1|title =Molybdenum disulfide as a lubricant: A review of the fundamental knowledge |date =1967|last1 =Winer|first1 =W.|journal =Wear|volume =10|pages=422–452|issue =6|hdl =2027.42/33266 |url =https://deepblue.lib.umich.edu/bitstream/2027.42/33266/1/0000658.pdf|hdl-access =free}}</ref>
* When combined with small amounts of cobalt, MoS<sub>2</sub> is also used as a catalyst in the [[hydrodesulfurization]] (HDS) of petroleum.  In the presence of hydrogen, this catalyst facilitates the removal of nitrogen and especially sulfur from the feedstock, which otherwise would poison downstream catalysts.  HDS is one of the largest scale applications of catalysis in industry.<ref>{{cite book| author =Topsøe, H. |author2=Clausen, B. S. |author3=Massoth, F. E. | title =Hydrotreating Catalysis, Science and Technology| publisher = Springer-Verlag| location= Berlin| date = 1996}}</ref>
* Molybdenum oxides are important catalysts for selective oxidation of organic compounds.  The production of the commodity chemicals [[acrylonitrile]] and [[formaldehyde]] relies on MoO<sub>''x''</sub>-based catalysts.<ref name="ullmann"/>
* [[Molybdenum disilicide]] (MoSi<sub>2</sub>) is an electrically conducting [[ceramic]] with primary use in [[heating element]]s operating at temperatures above 1500&nbsp;°C in air.<ref>{{cite book|url=https://books.google.com/books?id=FbMfaqSgOxsC&pg=PA141|page=141|title=Electroceramics: materials, properties, applications|author=Moulson, A. J. |author2=Herbert, J. M.|publisher=John Wiley and Sons|date=2003|isbn=978-0-471-49748-6}}</ref>
* [[Molybdenum trioxide]] (MoO<sub>3</sub>) is used as an adhesive between [[Vitreous enamel|enamels]] and metals.<ref name="elemental" />
* [[Lead molybdate]] (wulfenite) co-precipitated with lead chromate and lead sulfate is a bright-orange pigment used with ceramics and plastics.<ref>[http://www.imoa.info/ International Molybdenum Association] {{Webarchive|url=https://web.archive.org/web/20080309010036/http://www.imoa.info/ |date=2008-03-09 }}. imoa.info.</ref>
* The molybdenum-based mixed oxides are versatile catalysts in the chemical industry. Some examples are the catalysts for the oxidation of carbon monoxide, propylene to [[acrolein]] and acrylic acid, the [[ammoxidation]] of propylene to acrylonitrile.<ref>{{cite book|editor=Fierro, J. G. L. |title=Metal Oxides, Chemistry and Applications|date=2006|publisher=CRC Press|pages=414–455}}</ref><ref>{{cite book|author1=Centi, G. |author2=Cavani, F. |author3=Trifiro, F. |title=Selective Oxidation by Heterogeneous Catalysis|date=2001|publisher=Kluwer Academic/Plenum Publishers|pages=363–384}}</ref>
* Molybdenum carbides, nitride and phosphides can be used for hydrotreatment of rapeseed oil.<ref>{{cite journal |last1=Horáček |first1=Jan |last2=Akhmetzyanova |first2=Uliana |last3=Skuhrovcová |first3=Lenka |last4=Tišler |first4=Zdeněk |last5=de Paz Carmona |first5=Héctor |title=Alumina-supported MoNx, MoCx and MoPx catalysts for the hydrotreatment of rapeseed oil |journal=Applied Catalysis B: Environmental |date=1 April 2020 |volume=263 |pages=118328 |doi=10.1016/j.apcatb.2019.118328 |s2cid=208758175 |language=en |issn=0926-3373|doi-access=free |bibcode=2020AppCB.26318328H }}</ref>
* [[Ammonium heptamolybdate]] is used in biological staining.<ref>{{cite journal |last1=De Carlo |first1=Sacha |last2=Harris |first2=J. Robin |title=Negative staining and cryo-negative staining of macromolecules and viruses for TEM |journal=Micron |volume=42 |date=2011 |issue=2 |pmid=20634082 |pmc=2978762 |doi=10.1016/j.micron.2010.06.003 |pages=117–131}}</ref>
* Molybdenum coated soda lime glass is used in CIGS ([[copper indium gallium selenide]]) [[solar cell]]s, called [[Copper indium gallium selenide solar cells|CIGS solar cells]].
* [[Phosphomolybdic acid]] is a stain used in [[thin-layer chromatography]]<ref>{{cite web | title = Stains for Developing TLC Plates | url = https://www.chemistry.mcmaster.ca/adronov/resources/Stains_for_Developing_TLC_Plates.pdf | publisher = McMaster University}}</ref> and [[Masson's trichrome|trichrome]] staining in [[histochemistry]].<ref>{{cite journal |last1= Everett |first1= M.M. |last2= Miller |first2= W.A. |date= 1974 |title= The role of phosphotungstic and phosphomolybdic acids in connective tissue staining I. Histochemical studies |journal= The Histochemical Journal |volume= 6 |issue= 1 |pages= 25–34 |doi= 10.1007/BF01011535|pmid= 4130630 }}</ref>