What Is Black Oxide ?

Different from other surface treatments

Black oxidation is a chemical conversion coating metal surface treatment process. It improves corrosion resistance and increases surface hardness by forming a thin oxide film on the metal surface, while also giving the metal a smooth black appearance.

Compared with galvanizing, black oxidation forms a thin and beautiful oxide film, which is suitable for high-precision and internal parts, providing basic corrosion protection and good wear resistance. Galvanizing deposits a layer of zinc on the metal surface by electroplating or hot-dip plating. The thickness of electroplated zinc is generally 5 to 25 microns, and hot-dip galvanizing is thicker. The zinc layer provides strong anti-corrosion protection, especially suitable for outdoor and humid environments, and is widely used in building materials, automotive parts and fasteners.

Compared with painting, black oxidation forms a thin film through chemical reaction, which will not peel or crack. It is suitable for mechanical parts and provides wear resistance and anti-corrosion protection. Painting forms an organic coating on the metal surface by spraying or brushing. Although the coating is thicker, it may peel or crack and requires regular inspection and repainting to prevent corrosion.

Compared with electroplating, black oxidation is relatively environmentally friendly, does not produce a large amount of wastewater and waste, and provides basic anti-corrosion protection and aesthetic effects. Electroplating deposits a layer of metal (such as nickel, chromium) through an electrochemical reaction, which can provide a variety of metal coatings suitable for a variety of functional needs. Its corrosion resistance and conductivity depend on the metal used.

Compared with anodizing, black oxidation is applicable to a wide range of materials, including various metals, providing basic anti-corrosion protection and aesthetic effects. Anodizing is mainly used for aluminum and its alloys. Through electrochemical reactions, a hard, wear-resistant and corrosion-resistant aluminum oxide film is formed on the aluminum surface. It can be dyed to provide stronger anti-corrosion protection and aesthetic effects.

In general, black oxidation is an economical and affordable surface treatment method for metal products that need to enhance corrosion resistance and aesthetics. Compared with galvanizing, painting, electroplating and anodizing, black oxidation has its unique advantages in terms of scope of application, cost and environmental protection.