What is the typical bath temperature?
Acid zinc plating is typically 20-40°C, alkaline zinc plating 40-60°C. Too high a temperature can easily decompose the additives, while too low a temperature can slow the deposition rate.
What is the typical coating thickness requirement?
For general corrosion protection, the requirement is 5-15μm, while for high-strength corrosion protection (such as automotive parts), 15-30μm is required. The specific requirements are determined by the product standard.
What is a "leveling agent"? What is its function?
Also known as a leveling agent, it improves current distribution, ensuring a more uniform coating thickness on complex parts (such as deep holes and corners), and preventing areas of excessive thinness.
Why is passivation required after electrogalvanizing? The zinc layer itself is susceptible to oxidation. Passivation (such as chromate passivation and chromium-free passivation) forms a dense passive film on the surface, significantly improving corrosion resistance.
What is the core difference between cyanide-free zinc plating and cyanide-containing zinc plating?
Cyanide-free zinc plating uses environmentally friendly chelating agents to replace highly toxic cyanide. It is highly safe and has low pollution, but it requires stricter process control. Cyanide zinc plating has stable coating quality, but has high environmental risks and is gradually being replaced.