Surface treatment refers to the physical or chemical method of forming a layer on the surface of material with certain or multiple special properties .Surface treatment can improve the product appearance, texture, function and other aspects of performance.
◑ appearance: color, pattern, logo, luster/line (3 d and 2 d)
◑ texture: feel, roughness, life time(quality), streamlined, etc
◑ function: hardening, fingerprint resistance, scratch resistance
For metal parts, the commonly used surface treatment methods are anodic oxidation, electrophoresis, micro-arc oxidation, PVD vacuum plating, electroplating, powder spraying, metal drawing, sandblasting, polishing, etching, etc. Today I will take apart 10 kinds of most common surface treatments for metal.
Anodizing: it is mainly the anodizing of aluminum, which forms a layer of Al2O3 (alumina) film on the surface of aluminum
and aluminum alloy by means of electrochemical principle.This layer of oxidation film has protective, decorative, insulating, wear resistance and other special characteristics
Monochrome and gradient:
Polishing/sandblasting/wire-drawing → deoiling → anodizing → neutralization → staining → hole sealing → drying
(1)Polishing/sandblasting/wire-drawing → degreasing → shielding → anodizing 1→ anodizing 2 → hole sealing → drying
(2) polishing/sandblasting/wire-drawing → oil removal → anodizing 1 → radium carving → anodizing 2 → hole sealing → drying
Technical difficulties and key improvement points
The yield level of anodic oxidation is related to the cost of the final product. The key to improve the yield of anodic oxidation lies in the appropriate amount of oxidant,appropriate temperature and current density, which requires manufacturers of structural parts to continuously explore and seek breakthroughs in the production process.
2. Laser carving:
The beam energy and spot size are mainly determined according to the marking
size and material characteristics, and finally all are controlled by the computer.
It is applied in electronic components, hardware products, tool accessories, integrated circuit (IC), electrical appliances, mobile communication, precision equipment, glasses and clocks, jewelry, automobile accessories, plastic keys, building materials, PVC pipe and other industries, can be seen everywhere in daily life.
Apart from laser carving, another chemical method called etching, it is not so widely used in small batch mockups.
3.Physical vapor deposition (PVD) :
it is an industrial process in which thin films are deposited mainly by Physical processes.
Cleaning before PVD → vacuumizing in furnace → washing target and ion cleaning → coating → coating ends, cooling out → post-treatment (polishing, AFP)
PVD can be used to coat cermet decorative coatings with high hardness and wear resistance.
It is a technology of attaching a layer of metal film on the metal surface by virtue of electrolysis, thus preventing corrosion, improving wear resistance, electrical conductivity, reflective 5.property and improving appearance.Electroplating is common in zinc, chromium, nickel and so on.
Pretreatment → cyanide-free alkali copper → cyanide-free white copper tin → chrome plating – technical features –
- Coating with high gloss and high quality metal appearance;
- the substrates are SUS, Al, Zn, Mg, etc.;The cost is lower than PVD.
Environmental protection is poor and the risk of environmental pollution is high.
5. Powder coating:
Powder coating is sprayed onto the surface of the workpiece with Powder spraying equipment (electrostatic spray molding machine). Under the electrostatic action, the Powder will evenly adsorb on the surface of the workpiece, forming a powdery coating.Powder coating after high temperature baking leveling curing, into different effects (powder coating of different kinds of effects) of the final coating.
- Rich color, highlights and matte are optional;
- Low cost, suitable for the shell of building furniture products and radiators;
- High utilization rate, 100% utilization, environmental protection;
- Strong masking defect ability;
- Imitation of wood grain effect.
At present, mostly used in metal ketchen ware such as cooker, pot ,sometimes use in big boxes for electronics.
it is a kind of surface treatment method that forms line lines on the surface of workpiece through grinding products, and plays a decorative effect.
According to the different lines after drawing can be divided into: straight line brushing, random line brushing, ripple, spiral.
Brushing can make the metal surface obtain non-mirror metal luster, at the same time, Brushing can also eliminate the subtle defects on the metal surface.
it is a kind of technology that USES compressed air as power to form high-speed jet beam to spray materials to the surface of the workpiece to be processed at high speed, so that the appearance or shape of the surface of the workpiece surface changes to obtain a certain degree of cleanliness and different roughness.
- Achieve different reflections or mattes.
- Can clean the small burrs on the surface of the workpiece, and make the surface of the workpiece more flat, eliminate the harm of burrs, and improve the level of the workpiece.
- Remove residual dirt left during processing, improve the smoothness of the workpiece, make the workpiece show uniform and uniform metal color, and make the appearance of the workpiece more beautiful and good-looking.
Using flexible polishing tools and abrasive particles or other polishing media to modify the surface of the workpiece.
According to different polishing processes: coarse polishing (basic polishing process), middle polishing (finishing process) and
fine polishing (polishing process), selecting appropriate polishing wheel can achieve the best polishing effect and improve the polishing efficiency at the same time.
Improve the size accuracy or geometric shape accuracy of the workpiece, to get smooth surface or mirror gloss, but also can eliminate the gloss.
Above eight method are included, but, no limited to. welcome if you have any active ideas.