Zinc-nickel plating (sometimes referred to as Zn-Ni plating) is quickly growing as a substitute for cadmium plating. The primary advantage of zinc-nickel plating over cadmium — the reason why many are switching — is that cadmium is a known carcinogen. That is kind of a big deal, honestly. In many other ways, cadmium and zinc-nickel plating are equals, or nearly so. When you have two options that are nearly equal in all other respects, and one is known to cause cancer in humans, the answer becomes pretty easy, right?
Okay, maybe you're not using cadmium in your industrial or manufacturing business, and you're just starting to look at zinc-nickel plating. You're just starting to manufacture parts that might need high-performance plating like zinc-nickel plating. What does it have to offer?
A part that has zinc-nickel plating will have a uniform, crystalline, and smooth structure. This means 2 things.
First: It offers superior corrosion protection. (Compared to cadmium, zinc-nickel is as good or better in this respect.) Zinc is already commonly used as a protection against corrosion, specifically in sacrificial conversion. Zinc preferentially corrodes compared to, say, steel, and the corroded zinc deposits also protect the steel. Allying zinc with a true alloy, nickel, doubles or even triples the corrosion protection that zinc can offer. It's still a sacrificial type plating, but more durable and longer lasting. It can even be used in salt water environments with expectations that it will last.
Second: It offers excellent wear resistance. The uniform, crystalline structure of how zinc-nickel plating deposits on a part means that there is a lot less friction than would otherwise be. It's a particularly regular coating, and therefore, the irregularities that might catch and cause abrasion or friction wear on a part are much less likely.
Zinc-nickel plating is also better able to handle higher temperatures, which is one of the reasons it's been used more and more by the automotive and aircraft manufacturing industry. It maintains all of it's properties up to hotter temperatures than some other coating types, which is a real advantage in small hot moving parts.
The uniformity of the structure also means that the parts that are coated with zinc-nickel plating are still bendable. This means you can do some work on a part after it's been plated and still rely on the integrity of the plating. This could be really valuable to some manufacturing processes.
For more information, contact a zinc-nickel plating service.
