Project Description
After electroplate other metal on the surface of aluminium and aluminium extrusion, it can significantly improve the surface physical or chemical properties. For example, electroplate silver on the surface can improve the electrical conductibility; electroplate copper, nickel or tin on the surface, it’s to make aluminium alloy easy to weld; electroplate chromium is to improve wear resistance; In the decorative aspect, actually mostly adopted electroplate chromium.
Aluminium and aluminium alloy surface electroplating have long been tried and used in actual production.
The factors that oxidizing material existing between aluminium alloy and electroplated layer, the difference thermal expansivity between aluminium alloy and metal plating, pinhole and residual electroplating solution in electroplated layer etc.caused badly coating adhesion. Long time using will flake peeling off immediately after plating, even in the field of surface treatment, aluminium and aluminium alloy electroplating technology is still in the exploratory stage, no substantive breakthrough for quite a long time, it has not been formed complete, mature technology so far. The adhesion of the coating is not only the electroplating quality of aluminium and aluminium alloy but also the industry bottleneck.
General Process Flow of Aluminum Electroplating:
The electroplating process of aluminium has three parts: pretreatment, electroplating and post-treatment. Pretreatment is the most critical process for the quality of electroplating products. The main purpose is to remove the oil and grease on the surface of aluminium and aluminium alloy and to form the oxide film and other contaminants naturally.
The general technological process is: Skimmed – Water Processing – Alkaline Degreasing – Water Processign – Acid Pickling – Water Processing – Excitation – First Zinc Leaching – Water Processing – Dezincing – Water Processign – Second Zinc Leaching – Water Processign – Neutral Nickel Plating – Water Processign – Subsequent Electroplating.
