An alloy of copper tin and zinc has been used extensively in many different industries over the years. The ability of the metal to be formed in a wide range of shapes and sizes while still being relatively strong makes it ideal for a variety of applications. The specific characteristics of the alloy vary depending on the amount of tin added and how the tin is heated during manufacturing processes. The article below discusses one way to optimize these qualities by adding nickel ions to the plating bath composition.

Alloys of copper and tin have been used since antiquity for their attractive appearance, reasonable strength and corrosion resistance. The alloys can be made into musical instruments, food and beverage equipment, optical equipment and a number of other items where aesthetics are important.

The tin-copper alloys are known as bronzes and have been in wide use for centuries for their useful properties. Depending on the ratio of tin and copper in the alloy, the material can range from very hard and brittle to soft and malleable.

A particular class of bronzes, called leaded tin bronzes, is used for spring contact elements in electrical components. The alloys are characterized by excellent elastic spring properties and superior formability, especially in cold forming.

A problem encountered with the plating of leaded tin bronzes is that plated products can easily tarnish when they are cleaned prior to soldering. The tarnishing is caused by the formation of lead-tin compounds in the plated layer. The invention provides a method for plating a corrosion-resistant, bright silvery-colored copper-tin-zinc alloy having at least 10.9 atomic wt.% tin.