What is the difference between alkaline zinc plating process and acid zinc plating process?

What is the difference between alkaline zinc plating process and acid zinc plating process?

Mon Feb 19 08:43:44 CST 2024

Alkaline electrozinc plating process and acid electrozinc plating process are two common zinc plating methods for metal surface treatment, which differ in terms of the nature of the plating solution, the characteristics of the plated layer, the productivity and the environmental impact.

1. Properties of the plating solution:

Alkaline zinc plating: The use of zinc oxide as the main zinc source of alkaline solution, usually adding sodium hydroxide, galvanizing additives and some stabilizers to form a stable plating environment. Alkaline bath pH value is higher, usually above 12.

Acid zinc plating: mainly using sulfuric acid or zinc hydrochloric acid as a zinc source, adding some galvanizing additives to improve the brightness of the coating. Acidic baths have a low pH value, usually 4-6.

2. Coating characteristics:

Alkaline zinc plating: Due to the fine and dense zinc particles in the plating solution, this process can produce a fine coating, uniform distribution, good adhesion and high corrosion resistance.

Acid zinc plating: Usually able to form a coating on the metal surface more quickly, the resulting coating is usually thin and bright, but may be slightly less flexible and corrosion resistance than alkaline coating.

3. Production efficiency:

Alkaline zinc plating: The process is relatively slow and the current density is low, so it is suitable for workpieces requiring thicker coatings.

Acid zinc plating: Due to its faster coating growth rate, efficient production can be achieved, especially when dealing with small parts.

4. Environmental impact:

Alkaline zinc plating: The galvanizing additives used in cyanid-free alkaline galvanizing are more environmentally friendly, and do not contain heavy metals, and have less burden on the environment.

Acid zinc plating: Acidic solutions are more corrosive and may be more damaging to equipment and the environment, so more stringent waste disposal and environmental protection measures are needed.

In summary, the two zinc plating processes have advantages and disadvantages, and different application occasions and product requirements have an important impact on the selection of which galvanizing process. No matter which technology is chosen, it should balance product performance requirements, production efficiency and the need for environmental protection. If you want to ensure the quality of the galvanizing process, you can choose Bigely zinc plating additives.

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