Monel is a trademark of Special Metals Corporation for a series of nickel alloys, primarily composed of nickel (up to 67%) and copper, with some iron and other trace elements. Monel was created by David H. Browne, chief metallurgist for International Nickel Co. Monel alloy 400 is binary alloy of the same proportions of nickel and copper as is found naturally in the nickel ore from the Sudbury (Ontario) mines. Monel was named for company president Ambrose Monell, and patented in 1906. One L was dropped, because family names were not allowed as trademarks at that time. Compared to steel, Monel is very difficult to machine as it work-hardens very quickly. It needs to be turned and worked at slow speeds and low feed rates. It is resistant to corrosion and acids, and some alloys can withstand a fire in pure oxygen. It is commonly used in applications with highly corrosive conditions.
In the 1960s, Monel metal found bulk uses in aircraft construction, especially in making the frames and skins of experimental rocket planes, such as the North American X-15, to resist the great heat generated by aerodynamic friction during extremely high speed flight. Monel metal retains its strength at very high temperatures, allowing it to maintain its shape at high atmospheric flight speeds, a trade off against the increased weight of the parts due to Monel's high density.
Monel's corrosion resistance makes it ideal for marine applications such as piping systems, pump shafts, seawater valves, trolling wire, and strainer baskets. Monel is used as the material for valve pistons in some higher quality musical instruments such as trumpets, tubas and French horn rotors. Monel drill collars are used in surveying oil wells. Monel collars are used in drilling directional wells which require the well to be steered. Their use permits faster and more accurate surveys, reduce hazards, and decreases the cost of drilling directional or controlled oil wells. The good resistance against corrosion by acids and oxygen makes monel a good material for the chemical industry. Even corrosive fluorides can be handled within monel apparatus; this was done in an extensive way in the enrichment of uranium in the Oak Ridge Gaseous Diffusion Plant.