Alloys plating (bronze, brass & other)

Process Alloys plating (bronze, brass & other)

Alloys platings are used when properties which cannot be spontanousely aquired by pure metal coatings are required. Two or more metals fall simultaneously to the cathode. Control of the bath chemistry and alloy composition is very expensive.

The most common alloys are: brass (zinc-copper 70%) for decoration and for improving the adhesion between steel and rubber; bronze (90% copper, 10% tin), against adhesive wear; with 40-45% of copper, bronze is used against corrosion.

Other rarely used alloys are: lead-tin (tin 6%) for corrosion protection, (tin 60%) as soldering metal; nickel-iron (iron 40%) to replace nickel when too costly; nickel-tin (tin 65%) for corrosion resistance even in very highly acid environments.

Danish Name Elektrolytisk udfældning af legeringer

Category Surface treatments, Electroplating

Materials Coating materials:
Brass (Cu-Zn) Bronze (Cu-Sn)
Lead-Tin Nickel-Iron Nickel-Tin

Typical products Water tap (bronze)

References Arbeitsgemeinschaft - Galvanotechnik
Degussa AG
Galvanisk Kompagni A/S

Price notes The first price on the cell refers to bronze-plating, the second one to brass-plating. Over 5000 parts the price doesn't vary so much. The price is calculated for a typical average thickness: 15 micron (bronze); 3 micron (brass).

DKK/part	5 parts	100	5000
Small (1cm2)	84/84	11/11	0.056/0.041
Medium (1dm2)	115/113	20/18	0.44/0.26
Large (100dm2)	210/171	93/54	31/13

Price date December 1996

Environmen- tal notes Creation: In many cases it is used a cyanogen electrolyte, therefore very poisonous.
Disposal: Tin and copper can be problematic when recycling steel.

Additional info All alloys-plating processes are very costly because they require very expensive equipment and professional staff. Labour is the most important factor for pricing.

Photo Thomas Nissen (Computer graphics)