Zinc Nickel Alloy Plating

Zinc-nickel alloy is one of the alloys belonging to zinc alloy, which is mainly composed of two elements, zinc and nickel, in which the nickel content is generally between 12% and 16%. Because the zinc-nickel alloy has a layer of anti-corrosion coating, the corrosion resistance is very good, and the salt spray test time is very long, even up to 1000 hours. The zinc-nickel alloy products are mainly used for high salt spray requirements and high value-added products. The zinc-nickel alloy layer containing 13% nickel is 6-10 times higher than zinc and better than cadmium and cadmium-titanium alloys. At the same time, it has good mechanical properties and does not change the mechanical properties of the steel after plating. Excellent solderability, easy to solder under various conditions. The internal stress of the coating is small, which is comparable to the cadmium coating in the torsion-pull test. The plating solution has good dispersion ability and coverage ability, high current efficiency, and the coating are bright and smooth.

Zinc-nickel alloy plating solutions include weak acid chloride type, sulfate type, and alkaline zinc acid type.

What are the benefits of zinc nickel? Zinc nickel has increasingly become the finish of choice for many industries with high corrosion and high-performance needs. It is a fast-growing segment of the electroplating market, with usage nearly tripling over the past five years. The alloy has many properties that appeal to manufacturers in the fastener, foundry, automotive and heavy equipment industries. It is also being used as a potential replacement for cadmium in the defense industry. Zinc-nickel alloys have excellent corrosion resistance, most deposits in the 12% to 15% alloy range produce coatings that can reach 250+ hours for the first white corrosion and 1000 for the first red corrosion + hours. Zinc nickel has a Vickers hardness of 400 to 500 HV – pure zinc deposits have a hardness of only around 100 HV. Because handling and assembly can be a destructive process for softer coatings such as zinc and zinc flakes, the hardness and overall corrosion protection of zinc-nickel alloys make alloy deposits a tight spot requiring further handling or assembly. Ideal for firmware or components.

Zinc-nickel alloys have the following advantages:

1. Excellent corrosion resistance.
2. The thickness is kept within the thread tolerance range of 5~15μm
3. There is sufficient bonding force between the coating and the substrate
4. Excellent thermal fatigue resistance
5. Low hydrogen embrittlement.
6. Excellent wear resistance
7. The process is easy to operate

Process flow: pre-plating acceptance → degreasing → water washing → pickling and rust removal → cleaning → activation → water washing → electro-galvanized nickel alloy → water washing → passivation → water washing → drying → classification and packaging.