Surface Treatment

Surface treatment technology refers to the protection of base materials by modifying the surface of materials or coating a layer of other materials.

The purpose of surface treatment is to meet the requirements of corrosion resistance, wear resistance, decoration or other special functions of the product. For metal castings, our common surface treatment methods are mechanical grinding, chemical treatment, surface heat treatment and spraying surface. Surface treatment is to clean,  deburr, degrease and deoxidizing of the workpiece.

Surface treatment can be divided into four aspects:

Mechanical surface treatment: sand blasting, shot blasting, grinding, rolling, polishing, polishing, spraying, painting, oil painting, etc.

Chemical surface treatment: bluing and blackening, phosphating, pickling, electroless plating of various metals and alloys, TD treatment, QPQ treatment, chemical oxidation, etc.

Electrochemical surface treatment: anodizing, electrochemical polishing, electroplating, etc.

Modern surface treatment: chemical vapor deposition (CVD), physical vapor deposition (PVD), ion implantation, ion plating, laser surface treatment, etc.

Pickling and passivation treatment: it refers to the process of immersing metal parts in pickling and passivation solution until the surface of the workpiece becomes uniform silver white.

1. Electroplating

Electrolysis is the process of attaching a metal film to the surface of metal to prevent corrosion. It is a kind of technology that can improve the solderability, conductivity and aesthetics. It is usually plated with gold, silver, nickel, zinc and tin.

Advantages: after plating, the surface gloss is high and the metal appearance is beautiful. It is a surface treatment process that meets most electronic components.

2. Anodizing

It is mainly the anodization of aluminum material, which uses the electrochemical principle to form a layer of aluminum oxide film on the surface of aluminum and aluminum alloy. This oxide film has special characteristics such as protection, decoration, insulation and wear resistance

Advantages: it can improve the intensity and realize any color except white. It can realize nickel free sealing and meet the requirements of European and American countries for nickel free.

3. Electrophoresis

It is used for stainless steel, aluminum alloy, etc, it can make the products present various colors, keep the metallic luster, and enhance the surface performance, with good corrosion resistance.

Advantages: multi color surface treatment can be done, and surface treatment of complex structure can be realized; And can cooperate with the subsequent processes of sand blasting, polishing and brushed.

4. Micro arc oxidation

The process of applying high voltage in electrolyte solution (generally weak alkaline solution) to form ceramic surface facial mask layer is the result of the synergistic effect of physical discharge and electrochemical oxidation.

Advantages: Ceramic texture, mostly used for appearance, and good heat dissipation performance, but single color, high cost.

5. PVD vacuum plating

Physical vapor deposition (PVD) is a technology that mainly uses physical processes to deposit thin films.

Advantages: the metal surface can be coated with high hard plating and high wear resistance cermet decorative coating.

6. Powder spraying

Powder coating is sprayed onto the surface of the workpiece by powder spraying equipment (electrostatic plastic spraying machine). Under the action of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powdery coating; The powder coating is leveled and cured by high-temperature baking, and becomes the final coating with different effects (different kinds of effects of powder coating).

Advantages: rich color, highlight and matte optional; Low cost, suitable for building furniture products and chassis shells, etc., with strong ability to shield defects.

7. Metal brushed

It is a surface treatment method that forms lines on the surface of the workpiece by grinding the product to achieve decorative effect. According to the different lines after brushed, it can be divided straight line brushed, random brushed, corrugated brushed, swirl brushed.

Advantages: the wire drawing treatment can make the metal surface obtain a non mirror like metallic luster, and the brushed treatment can also eliminate the fine defects on the metal surface.

8. Sandblasting

A process in which compressed air is used as power to form a high-speed jet beam to spray the sprayed material onto the surface of the workpiece to be treated at high speed, so as to change the appearance or shape of the outer surface of the workpiece surface and obtain a certain degree of cleanliness and different roughness.

Advantages: achieve different reflection or matte. It can clean the micro burrs on the surface of the workpiece and make the surface of the workpiece more flat.

9. Polishing

The surface modification of workpieces using flexible polishing tools and abrasive particles or other polishing media.

Advantages: it does not change any physical properties of the material, and can be used as a pretreatment process for other surface treatments.