(or cupronickel), an alloy of copper, mainly with nickel (5–30 percent). It is a single-phase alloy in the form of a solid solution; it is readily worked by hot or cold pressure shaping. Its tensile strength after annealing is about 400 meganew-tons per sq m (40 kilograms-force per sq mm).
The most valuable property of melchior is its high corrosion resistance in air, fresh water, and seawater. An increase in nickel content, as well as the addition of iron and manganese, provides greater corrosion and cavitation resistance, particularly in seawater and water vapor. The alloy MNZhMts 30–0.8–1 (30 percent Ni, 0.8 percent Fe, 1 percent Mn) is used in naval ship-building, particularly for the manufacture of condenser pipes. Unlike brass and bronze, melchior has a silvery rather than yellowish color because of its nickel content. The silver color and high corrosion resistance determined the use of the alloy MN19 (19 percent Ni) in the manufacture of tableware and other consumer articles, including chased goods. Copper-nickel alloys, copper-zinc-nickel alloys, and even silver-plated brass were previously known as melchior; therefore, articles made from these materials are often referred to as melchior products.
I. I. NOVIKOV