Melchior (alloy) corrosion in air, freshwater and seawater. Increasing content of nickel iron or manganese improves corrosion and cavitation resistance, especially in sea water and atmospheric water vapor. The alloy of 30% Ni, 0.8% Fe, 1% Mn and 68.2% copper is used in maritime shipping, in particular for the manufacture of condenser tubes. Thanks to the nickel, melchior, unlike brass and bronze, has not a yellow but a silver color. Together with high corrosion resistance, this silvery color is preferred for the manufacture of household utensils. Melchior (alloy) In metallurgy, melchior is an alloy of copper, mainly with nickel (5–30%). Its name
Zinc–copper couple greater than 90%, although an alloy containing similar proportions of zinc and copper is used in some cases. The couple is frequently prepared as a darkly-colored powder and is slurried in an ethereal solvent prior to being used in slight excess relative to the substrate. Activation of zinc by copper is essential to the couple’s utility, but the origin of this effect is poorly documented. It is speculated that copper enhances reactivity of zinc at the surface of the alloy. Zinc–copper couple has been prepared by numerous methods, which vary mainly with respect to the source of copper, but also