Copper is divided into: brass, bronze, red copper, white copper. Due to the influence of the environment, the copper surface will be oxidized to varying degrees, so it also needs surface protection treatment to keep its bright as new appearance and corrosion resistance and oxidation resistance for a long time. That requires a variety of copper surface treatment processes.
Common copper surface treatment processes include the following:
1. Bright cleaning of copper: it is mainly to restore the bright color of copper itself after thoroughly cleaning the stains, impurities, spots, oil stains and other dirt on the copper surface. It is also a necessary process before copper passivation.
2. Copper passivation: as we all know, the main function of passivation is to prevent oxidation and corrosion. As copper is an active metal, it is particularly easy to oxidize and grow spots in humid or special environments, and even appear verdigris. Therefore, copper passivation is one of the most necessary processes. It can effectively protect the surface of copper parts.
3. Anodic oxidation: take copper parts as anode and form oxide film on its surface by electrolysis. Oxide films change the surface state and properties, such as surface coloring, improving corrosion resistance, enhancing wear resistance and hardness, protecting the surface of copper parts, etc.
4. Electroplating: the purpose of electroplating is to coat the copper substrate with metal coating and change the surface properties or dimensions of the copper substrate. Electroplating can enhance the corrosion resistance of copper, increase hardness, prevent abrasion, improve conductivity, smoothness, heat resistance and surface beauty.
5. Copper chemical polishing: immerse the copper parts directly in the copper chemical polishing liquid, so that they can quickly reach the beautiful color as bright as new, and quickly remove the surface oxide. The surface size will change accordingly, but it can be manually controlled. The copper parts after chemical polishing shall be passivated as soon as possible to prevent them from being oxidized and discolored again.