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
Printed circuit board coated with solder by hot air solder levelling (HASL). The HASL finish prevents oxidation from the underlying copper, thereby guaranteeing a solderable surface. This solder was a tin-lead alloy, however new solder compounds are now used to achieve compliance with the RoHS directive in the EU, which restricts the use of lead. One of these lead-free compounds is SN100CL, made up of 99.3% tin, 0.7% copper, 0.05% nickel, and a nominal of 60 ppm germanium. It is important to use solder compatible with both the PCB and the parts used. An example is ball grid array (BGA) using tin-lead solder