MONEL METAL, the trade-marked name of a copper nickel alloy developed in 1905. The alloy contains about 67% nickel, 28% copper, 2% iron, together with small amounts of carbon, manganese and silicon, and is made directly from the copper-nickel ores of Sudbury, Ont., Canada, by roasting the copper-nickel converter matte (see NICKEL) and reducing the resulting oxide to metal with charcoal.
The alloy is nickel white in colour and its distinguishing charac teristics are its rust-proofness and corrosion-resistance, its ready manufacture by all usual methods and its satisfactory mechanical properties. Its corrosion rate is low in moist atmosphere, fresh and sea-water, solutions of most organic salts, alkalis, and of all except nitric and other strongly oxidizing acids. Very corrosive solutions, such as those of ferric salts, of sulphurous acid, of the free halogens, attack it appreciably. The alloy is quite malleable,
both hot and cold, and machinable. It is readily melted and cast. It can be forged, rolled, machined, drawn and welded and in consequence is readily fabricated and is available in a wide variety of commercial forms. Some of the most important characteristics of monel metal are: density, 8.80; melting range (about), 1,375° C; modulus of elasticity, 25,000,000 lb. per sq.in. ; tensile strength (hot-rolled), 90,000 lb. per sq.in., tensile strength (cold rolled), ioo,000 to 150,000 lb. per sq.in. ; elongation (hot-rolled), 5o% ; Brinell hardness (hot-rolled), 150; thermal expansion (25-100° C), .000014 per i° C; electrical resistivity, 42.5 mi crohms per c.c.; magnetic permeability (100 Gauss), 10-15; forging and rolling temperature range, 940-1,240° C.