Mechanical Property Weldable Aluminum Alloys

Nickel—Copper. In the soHd state, nickel and copper form a continuous soHd solution. The nickel-rich, nickel—copper alloys are characterized by a good compromise of strength and ductihty and are resistant to corrosion and stress corrosion ia many environments, ia particular water and seawater, nonoxidizing acids, neutral and alkaline salts, and alkaUes. These alloys are weldable and are characterized by elevated and high temperature mechanical properties for certain appHcations. The copper content ia these alloys also easure improved thermal coaductivity for heat exchange. MONEL alloy 400 is a typical nickel-rich, nickel—copper alloy ia which the nickel content is ca 66 wt %. MONEL alloy K-500 is essentially alloy 400 with small additions of aluminum and titanium. Aging of alloy K-500 results in very fine y -precipitates and increased strength (see also Copper alloys). 

The Al-6Cu-Mn alloy differs from other aluminum alloys in that it has relatively good mechanical properties at low temperatures and, therefore, can be successfully used for low-temperature structures. Unlike the duralumin-type alloys, the Al-6Cu-Mn heat-treatable alloy contains more copper (5.8 to 6.8%) and no magnesium [ ]. It is similar to the USA alloy 2219. It has satisfactory weldability and mechanical properties over a wide range of temperatures from 20 K up to 523 K, making it suitable for welded vessels for liquefied gas transportation and storage. 

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