Zinc-nickel alloy plating
Medium nickel-zinc alloy plating
Enables 4 to 6 times higher corrosion resistance than ordinary zinc
A plating surface with a metallic luster is achieved at around a 5 to 10 Wt% zinc to nickel alloy ratio.
Because this is an alloy made of zinc and nickel, the potential difference of the zinc can be reduced, excessive sacrificial corrosion of the zinc can be suppressed, and corrosion resistance 4 to 6 times higher than ordinary zinc can be obtained.
Adopted for automotive and other parts
In addition, medium nickel-zinc alloy plating is adopted for automotive and other parts because of its excellent heat resistance.
The quality of the appearance and corrosion resistance of the zinc nickel alloy plating is further improved by applying a Cosmer treatment after plating.
(Because the appearance becomes a color similar to stainless steel, this is also called a "stainless coating.")
The largest feature of medium nickel-zinc alloy plating is that the plating film is not formed unless the alloy ratio is around 5 to 10% when treated with a chloride bath.
For this reason, in some places automobile manufacturers and parts makers have introduced medium nickel-zinc alloy plating to purposefully use that characteristic from the viewpoint of quality assurance.
Treatment is available only in a white finish.
High nickel-zinc alloy plating
Corrosion resistance higher than medium nickel-zinc alloy plating
Corrosion resistance higher than that of medium nickel-zinc alloy plating can be obtained with an about 15 Wt% nickel alloy to zinc ratio.
This is the condition that offers the best corrosion resistance.
It is possible to improve the protection of excessive sacrificial corrosion of the zinc more than with medium nickel-zinc alloy plating, enabling corrosion resistance 7 times to 10 times higher than that obtained with ordinary zinc plating.
Outstanding environmental responsiveness
Even in high temperature environments the coating does not come off and has very high corrosion resistance. The high temperature corrosion resistance does not decrease even at 200°C.
Moreover, since the nickel content is high, the hardness of the coating is Hv 400 and scratch resistance is also good.
Additionally, although medium nickel-zinc alloy plating can not blacken, high nickel-zinc alloy plating can easily be treated with a black finish.
Treatment is available in a white or black finish.