Monel is a group of alloys of nickel (from 52 to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon. Monel is not a cupronickel alloy because it has less than 60% copper.
Stronger than pure nickel, Monel alloys are resistant to corrosion by many aggressive agents, including rapidly flowing seawater. They can be fabricated readily by hot- and cold-working, machining, and welding.[2]
Monel was created in 1905 by Robert Crooks Stanley, who at the time worked at the International Nickel Company (Inco).[3] Monel was named after company president Ambrose Monell, and patented in 1906.[4] One L was dropped, because family names were not allowed as trademarks at that time.[1] The trademark was registered in May 1921,[5] and the name is now a trademark of Special Metals Corporation.
As an expensive alloy, it tends to be used in applications where it cannot be replaced with cheaper alternatives. For example, in 2015 Monel piping was more than three times as expensive as the equivalent piping made from carbon steel.[6]