What are the processes for surface treatment of copper locks?

1. ‌Chemical treatment‌
Chemical polishing‌: Use acidic or alkaline solution to remove oxides and oil stains on the surface of the copper lock to restore its luster‌
Passivation treatment‌: Form a dense oxide film on the surface of the copper lock by chemical or electrochemical methods, which can keep color unchanged for more than 3 years‌
Antioxidation treatment‌: Use special passivation solution (such as T401, T402) to significantly improve corrosion resistance, and the salt spray test of copper can reach more than 72 hours‌
2. ‌Mechanical treatment‌
Mechanical polishing‌: Remove the surface oxide layer by wire brush roller or shot blasting, suitable for batch processing‌
Wire drawing process‌: Draw out textures on the surface of the copper lock, which has both beautiful and anti-slip functions‌
3. ‌Electroplating process‌
Chrome/nickel plating‌: Enhance surface hardness (chrome plating hardness can reach HV900) and wear resistance, while providing mirror effect‌
Gold/silver plating‌: Mostly used for high-end copper lock decoration, requires electrolytic polishing pretreatment‌
4. ‌Special craft‌
Gilding/inlaid gold‌: Traditional manual technique, inlaid with gold foil or gold wire for decoration‌
Anodizing‌: Suitable for aluminum-containing copper alloy locks, can be dyed to achieve a variety of appearances‌
Laser etching‌: Used for personalized pattern engraving, with an accuracy of up to 0.1mm‌
5. ‌Compound process‌

Typical process example:

Degreasing cleaning → 2. Chemical polishing → 3. Passivation treatment → 4. Electroplating/spraying → 5. Drying and curing‌
The brass lock head can maintain a golden luster for more than 3 years after this treatment‌.