Difference between revisions of "Monel"

Latest revision as of 09:23, 20 September 2010

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.^[2] One L was dropped, because family names were not allowed as trademarks at that time.^[1]

Properties

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. Small additions of aluminium and titanium form an alloy (K-500) with the same corrosion resistance but with much greater strength due to gamma prime formation on aging. Monel is typically much more expensive than stainless steel.

Monel alloy 400 has a specific gravity of 8.83, an electrical conductivity of approximately 3.4% IACS, and (in the annealed state) a hardness of 65 Rockwell B.^[3]

Uses

Aerospace applications

Especially in the 1960s, Monel metal found bulk uses in aircraft construction, especially in making the frames and skins of very high speed rocket planes that were made for experimental flights that generated great heat due to aerodynamic friction. Monel metal is dense, and hence parts that are made of it are heavy, but this factor had to be traded-off against the fact that Monel metal retains its strength at very high temperatures. One kind of rocket plane that used large amounts of Monel metal in its frame and its skin was the X-15 hypersonic rocket plane that flew from 1959 through 1968 to ever-increasing speeds and altitudes because of the continual improvements that were made in its rocket engine, its capacity for carrying liquid rocket fuel and oxidizer, and in its flight control system. Still, the fundamental body and skin of the X-15 remained the same. Its top speed of mach 6.7 was achieved in 1968, and its top altitude of 67 miles (115 kilometers) was achieved some years earlier.

Marine applications

Monel's corrosion resistance makes it ideal for marine applications such as piping systems, pump shafts, seawater valves, trolling wire, and strainer baskets. Some alloys are completely non-magnetic and are used for anchor cable aboard minesweepers,^[4] housings for magnetic-field measurement equipment, and have applications in the oil drilling industry. In recreational boating, Monel wire is used to seize shackles for anchor rods, Monel is used for water and fuel tanks, and for under water applications. It is also used for propeller shafts and for keel bolts.

However, because of the problem of electrolytic action in salt water (also known as Galvanic corrosion), in shipbuilding monel must be carefully insulated from other metals such as steel. The New York Times of August 12, 1915 published an article about a 215 foot yacht, "the first ship that has ever been built with an entirely monel hull," that "went to pieces" in just six weeks and had to be scrapped, "on account of the disintegration of her bottom by electrical action." The yacht's steel skeleton deteriorated due to electrolytic interaction with the monel. ^[5]

In seabird research, and bird banding or ringing in particular, Monel has been used to make bird bands or rings for many species such as albatross that live in a corrosive sea water environment.^[6]

Monel is also used for safety wiring in the aircraft industry to ensure that fasteners cannot come undone.

Musical instruments

Monel is used as the material for valve pistons in some higher quality musical instruments such as trumpets, tubas and french horn rotors. RotoSound introduced the use of Monel for electric bass strings in 1962, and these strings have been used by numerous artists, including Steve Harris of Iron Maiden, The Who, Sting, John Deacon, and John Paul Jones. Monel was in use in the early 1930s by other musical string manufacturers, such as Gibson Guitar Corporation, who continue to offer them for mandolin as the Sam Bush signature set.

Other

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. Here most of the larger diameter tubing for the uranium hexafluoride was made from monel.^[7]

Monel was used for US Military dog tags in WWI and WWII.

Monel is often used for kitchen sinks and in the frames of eyeglasses. It has also been used for firebox stays in fire-tube boilers.

Parts of the Clock of the Long Now, which is intended to run for 10,000 years, are made from Monel because of the corrosion resistance without the use of precious metals.^[8]

Monel was used for much of the exposed metal used in the interior of the Bryn Athyn Cathedral. This included large decorative screens, doorknobs, etc.^[1] Monel also has been used as roofing material in buildings such as Pennsylvania Station (New York City).^[1]

The 1991 - 1996 Acura (Honda) NSX came with a key made of Monel.^{[citation needed]}

Oilfield applications include using Monel in both flex and slick collars. Instruments which measure the Earth's magnetic field to obtain a compass reading are placed in the Monel collar which isolates sensors from the magnetic pull of drilling tools located above and below the Monel collars.

Monel is also used as a protective binding material on the outside of western style stirrups.

Monel is used to by Arrow Fastener Company for rustproof T50 staples.

Alloys

See also

• Cupronickel

References

Bibliography

• Shoemaker, Lewis E. (2006). "A century of monel metal: 1906–2006". JOM. 58: 22. doi:10.1007/s11837-006-0077-x.  |first2= missing |last2= in Authors list (help)

External links

• Monel Corrosioncs:Monel

de:Monel es:Monel it:Monel ms:Monel nl:Monel ja:モネル pl:Monel pt:Monel ru:Монель-металл sl:Monel

1. ↑ ^{1.0 1.1 1.2 1.3} Von Margot Gayle, David W. Look, John G. Waite (1992). "Monel". Metals in America's historic buildings: uses and preservation treatments. DIANE Publishing. pp. 39–41. ISBN 9780160380730. CS1 maint: Multiple names: authors list (link)
2. ↑ Ambrose Monell U.S. Patent 811,239 Issue date: Jan 1906
3. ↑ Nickel Alloy 400 (Monel)
4. ↑ Teeple, H. O. (1953). "Nickel and High-Nickel Alloys". Industrial & Engineering Chemistry. 45: 2215. doi:10.1021/ie50526a033. 
5. ↑ "New York Times, August 12, 1915: Big Yacht Now Junk After Six Weeks Use". The New York Times. August 12, 1915. Retrieved May 13, 2010. 
6. ↑ Ludwig, James P. (1981). "Band Wear and Band Loss in the Great Lakes Caspian Tern Population and a Generalized Model of Band Loss". Colonial Waterbirds. 4: 174–18. doi:10.2307/1521133. 
7. ↑ Milford, Robert (1958). "Engineering Design of Oak Ridge Fluoride Volatility Pilot Plant". Industrial & Engineering Chemistry. 50: 187. doi:10.1021/ie50578a032. 
8. ↑ Beech, Martin (2007). "The Clock of the Long Now — A Reflection" (PDF). The Journal of the Royal Astronomical Society of Canada. 101 (1): 4–5.