Editing Niobium (section)

===Niobium-based alloys===
{{Main article|Niobium alloy}}
[[File:Apollo CSM lunar orbit.jpg|thumb|Apollo 15 CSM in lunar orbit; dark nozzle of the [[Apollo command and service module#Service propulsion system|service propulsion system]] is made from niobium–titanium alloy |alt=Image of the Apollo Service Module with the moon in the background]]
'''C-103''' alloy was developed in the early 1960s jointly by the [[Wah Chang Corporation]] and [[Boeing]] Co. [[DuPont]], [[Union Carbide]] Corp., [[General Electric]] Co. and several other companies were developing [[Niobium alloy|Nb-base alloys]] simultaneously, largely driven by the [[Cold War]] and [[Space Race]]. It is composed of 89% niobium, 10% [[hafnium]] and 1% titanium and is used for [[liquid-propellant rocket|liquid-rocket]] [[Thrusters (spacecraft)|thruster]] [[nozzle]]s, such as the [[descent propulsion system|descent engine]] of the [[Apollo Lunar Module]]s.<ref name="hightemp">{{cite journal|url=https://www.cbmm.com/portug/sources/techlib/science_techno/table_content/sub_3/images/pdfs/016.pdf |title=Niobium alloys and high Temperature Applications |first=John |last=Hebda |journal=Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) |date=2 May 2001 |url-status=dead |archive-url=https://web.archive.org/web/20081217080513/http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_3/images/pdfs/016.pdf |archive-date=17 December 2008 }}</ref>

The [[Reactivity (chemistry)|reactivity]] of niobium with [[oxygen]] requires it to be worked in a [[Outgassing|vacuum]] or [[Inert gas|inert atmosphere]], which significantly increases the cost and difficulty of production. [[Vacuum arc remelting]] (VAR) and [[electron beam melting]] (EBM), novel processes at the time, enabled the development of niobium and other reactive metals. The project that yielded C-103 began in 1959 with as many as 256 experimental niobium alloys in the "C-series" (<u>C</u> arising possibly from <u>c</u>olumbium) that could be melted as buttons and rolled into [[Sheet metal|sheet]]. [[Wah Chang Corporation]] had an inventory of [[hafnium]], refined from nuclear-grade [[zirconium alloy]]s, that it wanted to put to commercial use. The 103rd experimental composition of the C-series alloys, Nb-10Hf-1Ti, had the best combination of formability and high-temperature properties. Wah Chang fabricated the first 500 lb heat of C-103 in 1961, ingot to sheet, using EBM and VAR. The intended applications included [[Gas turbine|turbine engine]]s and liquid metal [[heat exchanger]]s. Competing niobium alloys from that era included FS85 (Nb-10W-28Ta-1Zr) from [[Fansteel|Fansteel Metallurgical Corp]]., Cb129Y (Nb-10W-10Hf-0.2Y) from Wah Chang and [[Boeing]], Cb752 (Nb-10W-2.5Zr) from Union Carbide, and Nb1Zr from Superior Tube Co.<ref name="hightemp" />

[[File:Merlin nozzle 4105129088 9659a4df4e o.jpg|thumb|[[SpaceX Merlin#Merlin Vacuum (1C)|Merlin Vacuum]] nozzle made from a niobium alloy]]

The nozzle of the [[Merlin (rocket engine family)#Merlin Vacuum (1C)|Merlin Vacuum]] series of engines developed by [[SpaceX]] for the upper stage of its [[Falcon 9]] rocket is made from a C-103 niobium alloy.<ref name="NSPO">{{cite conference |title=Low-cost Launch Opportunities Provided by the Falcon Family of Launch Vehicles |first1=Aaron |last1=Dinardi |first2=Peter |last2=Capozzoli |first3=Gwynne |last3=Shotwell |conference=Fourth Asian Space Conference |year=2008 |location=Taipei |url=http://www2.nspo.org.tw/ASC2008/4th%20Asian%20Space%20Conference%202008/oral/S12-11.pdf|url-status=dead |archive-url=https://web.archive.org/web/20120315135217/http://www2.nspo.org.tw/ASC2008/4th%20Asian%20Space%20Conference%202008/oral/S12-11.pdf |archive-date=15 March 2012 }}</ref><ref>{{Cite web |last=Jackiewicz |first=Karolina |date=2021-07-21 |title='To boldly go where no man has gone before…', the alloy that has made space travel possible. |url=https://www.lipmann.co.uk/post/to-boldly-go-where-no-man-has-gone-before-the-alloy-that-has-made-space-travel-possible |access-date=2025-04-29 |website=Lipmann Walton & Co |language=en}}</ref>

Niobium-based superalloys are used to produce components to [[Hypersonic weapon|hypersonic missile]] systems.<ref>{{Cite journal |last1=Torres |first1=Guido L. |last2=López |first2=Laura Delgado |last3=Berg |first3=Ryan C. |last4=Ziemer |first4=Henry |date=2024-03-04 |title=Hypersonic Hegemony: Niobium and the Western Hemisphere's Role in the U.S.-China Power Struggle |url=https://www.csis.org/analysis/hypersonic-hegemony-niobium-and-western-hemispheres-role-us-china-power-struggle |language=en |website=CSIS |access-date=Oct 15, 2024}}</ref>