What is Monel?
Monel is an alloy (i.e. combination of two or more elements of which at least one is a metal, and where the resultant material has metallic properties). It is based on nickel (65-70%) and copper (20-29%) and also contains iron and manganese (5%) and other compounds.
Monel was discovered by Robert Crooks Stanley who worked for the International Nickel Company (INCO) in 1901. The new alloy was named in honor of the president of the company, Ambrose Monell.
Monel is a trademark of Special Metals Corporation
There are different commercial types of Monel such as Alloy 400, Alloy 401, Alloy R-405, Alloy 450, Alloy K-500, Monel 404 Copper-Nickel Alloy. Standard product forms are round, hexagon, flats, forging stock, pipe, tube, plate, sheet, strip, and wire.
Characteristics of Monel
- Highly resistant to corrosion. Monel is well known as a corrosion strong, rust-resistant material. It is resistant to corrosion and acids, and some alloys can withstand a fire in pure oxygen.
- Stronger than steel
- Low coefficient of thermal expansion
- Highly resistant to alkalis
- It can be welded, brazed and soldered
Monel is used for marine engineering, chemical and hydrocarbon processing equipment, valves, pumps, shafts, fittings, fasteners, and heat exchangers. It is also used as part of metal instruments and frames of eyeglasses.
In 1950's Monel started to be replaced by stainless steel which could produce the same forms at a lower cost (due to use of less nickel).
Typical Monel 400 has the following composition in weight (%).
C Max 0.3
Cu 28 - 34
Fe Max 2.5
Mn Max 2
Ni Min 63
S Max 0.024
Si Max 0.5
|MECHANICAL PROPERTIES |
|Tensile strength, Ultimate ||550 Mpa |
|Tensile strength, Yield ||240 Mpa |
|Elongation at Break ||48% |
|ELECTRICAL PROPERTIES || |
|Electrical Resistance ||5.47e-005 ohm-cm |
|Curie Temperature (the temperature above which a ferromagnetic substance loses its ferromagnetism) ||35°C |
|THERMAL PROPERTIES |
|CTE, linear 20°C ||13.9 µm/m-°C |
|Heat Capacity ||0.427 J/g-°C |
|Thermal Conductivity ||21.8 W/m-K |
|Melting Point ||1300 - 1350 °C |
|Solidus ||1300 °C |
|Liquidus ||1350 °C |