Surface Treatment of metals
Surface Treatment is applied after machining and can change the appearance, surface roughness, hardness and chemical resistance of the finished parts. There are different types of surface treatment.
None
None surface treatment is also called as-machined. No extra operations are performed on them, so no added cost and the parts have the tightest dimensional tolerances, but tool marks is visible.
Sand Blasting
Sand blasting is also known as abrasive blasting, which is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove surface contaminants. A pressurised fluid, typically compressed air, or a centrifugal wheel is used to propel the blasting material.
Feature
1. Visually pleasing matte or satin finish.
2. Available in different roughness.
3. Will affect critical dimensions and surface roughness.
4. Low-cost.
Powder Coating
Powder coating is typically applied electrostatically and then cured under heat. It is usually used to create a hard finish that is tougher than conventional paint, adds a thin layer of strong, wear and corrosion resistant protective polymer paint on the surface of a part.
Feature
1. Can be applied to parts of any material.
2. Available in many colors.
3. Higher impact resistance than anodizing.
4. Cannot be applied to small components or internal surface.
Polishing
Polishing is the process of using mechanical, chemical or electrochemical action to reduce the workpiece surface roughness. With polishing tools, abrasive particles or other polishing media to modify the surface of the workpiece, in order to obtain a bright, shiny and flat surface.
Feature
1. Can improve the fatigue and corrosion resistance.
2. Can be used as an intermediate process.
3. The strength is normally higher than their rougher counterpart.
Anodizing
Anodizing is a conversion process which is most commonly used for surface finishing of aluminum in particular. It adds a thin, hard, non-conductive ceramic coating on the surface, increasing their hardness, thermostability, corrosion and wear resistance.
Feature
1. Durable and visually pleasing.
2. high adsorption ability.
3. Can be colored to any pant.
4. Can be applied to internal surface.
Plating
Plating is the process of coating a metal surface with a thin layer of another metal or alloy by means of Electrolysis, in order to change the surface property or size of the substrate.
Plating is used to decorate objects, harden, reduce friction and alter conductivity, improve paint adhesion, IR reflectivity, solderability and wearability, for corrosion inhibition, radiation shielding and other purposes.
Electrophoresis
Under the action of an external DC power, colloidal particles in the dispersion medium move in the direction of the cathode or anode, this phenomenon is called electrophoresis. It’s divided into anodic electrophoresis and cathodic electrophoresis.
Feature
1. Lower cost.
2. Only applies to conductive metal surfaces.
3. Can completely cover the whole surface.
4. Less pollution than planting.
Wire Drawing
Wire drawing forms lines on workpiece surface by grinding products and plays a decorative effect. It can reflect the texture of metal materials, so it gets increasing popular and widely used.
Blackening
Blackening is a common chemical surface treatment. By immersing the workpiece in a strong oxidizing chemical solution to produce a layer of oxide film on the metal surface, in order to isolate air and achieve the purpose of rust prevention.
Above are common metal surface treatment types, if you would like to know more surface treatment please contact Huixia Metalworking team for more information.