Metal Products-Surface Finishing
Surface finishing is to improve the corrosion resistance and wear resistance of the product by changing the mechanical, physical and chemical properties of the surface layer. Traditional surface finishing methods mainly include: galvanizing, electrophoresis, bluing, blackening, passivation, phosphating, spraying, coloring, baking varnish, and sandblasting.

Metal Surface Treatment Technology
1、Anodizing
Anodized of aluminum is to generate a layer of Al2O3(alumina) film on the surface of aluminum and aluminum alloy using electrochemical principle. This layer of anodized film has special characteristics such as protective, decorative, insulating and abrasion resistance.

Technical features
1. Improve strength. 2. Realize any color except white. 3. Achieve nickel-free sealing to meet the requirements of Europe and America customer.

Technical difficulties and key points for improvement
The good rate of anodizing parts are related to the cost of the final product. The key point to improve the anodized good rate are the dosage, suitable temperature and current density.

2、Electrophoresis
Applied to stainless steel and aluminum alloy etc.Make the product show a variety of colors, maintain metallic luster and enhancing the surface performance with good anti-corrosion performance as well.
Technical features 1. Rich colors. 2. No metal texture, can be used with sandblasting, polishing, brushed, etc. 3. Achieve surface finishing of complex structures when processing in a liquid environment. 4. Massive production.
3、Vacuum Electroplating
It is an industrial manufacturing process that use physical processes to deposit thin films.
Technical features Can be coated on the metal surface with high-hardness, high abrasion resistance cermet decorative coating.

4、Electroplating
It is a technology that attached a metal film to prevent corrosion, improve abrasion resistance, electrical conductivity, reflectivity, and enhance aesthetics by electrolysis.
Technical features Advantages 1. The coating has high gloss and high-quality metal appearance. 2. The base material is SUS, Al, Zn, Mg, etc.; the cost is relatively low compared to PVD. Disadvantages
High risk of environmental pollution.


5、Powder coating
Use powder spraying equipment (electrostatic spraying machine) to spray the powder coating on the surface of the workpiece. Under the action of static electricity, the powder will be uniformly adsorbed on the surface of the workpiece to form a powdery coating. The powder coating is baked, leveled and cured at a high temperature, and becomes the final coating with different effects (different types of powder coating effects). Technical features Advantages 1. Rich colors, high gloss and matte finish are optional. 2. The cost is low, and it is suitable for the building and furniture products and heat sinks, etc. 3. High utilization rate, 100% utilization, environmental protection. 4. Strong ability to hide defects. 5. The wood grain effect can be imitated. Disadvantages High risk of environmental pollution.

6、Brushed
Brushed is a surface treatment method that forms lines on the surface of the workpiece by grinding the product to achieve a decorative effect.
According to the different lines after brushed, it can be divided into: Straight, Chaotic, Ripple, Swirling. Technical features It can make the metal surface obtain a non-mirror-like metallic luster, and at the same time, the brushed treatment can also eliminate the subtle defects on the metal surface.

7、Sandblasting
Sandblasting is powered by compressed air to form a high-speed jet beam to spray material on the surface of the workpiece to be treated at a high speed, so that the appearance or shape of the outer surface is changed, and obtained a certain cleanliness and different roughness. Technical features 1. Realize different reflective or matt. 2. It can clean the tiny burrs on the surface of the workpiece and make the surface smoother, eliminating the hazard of the burr and improving the grade of the workpiece. 3. Remove the residue left over from the pre-treatment, improve the finish of the workpiece, and make the workpiece show a uniform and consistent metal color, making the appearance of the workpiece more beautiful and attractive.

8、Polishing
Use flexible polishing tools and abrasive particles or other polishing media to modify the surface of the workpiece. For different polishing processes: rough polishing (basic polishing process), medium polishing (finishing process) and fine polishing (coating process), choosing a suitable polishing wheel can achieve the best polishing effect and improve polishing efficiency. Technical features Improve the dimensional accuracy or geometric accuracy of the workpiece to obtain a smooth surface or mirror gloss, and at the same time, it can eliminate the gloss.

9、Etching
Generally referred to as etching is also called photochemical etching, which refers to the removal of the protective film of the area to be etched after exposure to plate making and development, and connect with chemical solutions during etching to achieve the effect of dissolving and corroding, forming unevenness or hollowing out. Technical features Advantages Special effect on metal surface. Disadvantages
Most of the corrosive liquids (acids, alkalis, etc.) are harmful to the environment.