Surface finishing

Drill with coating (wear protection). A titanium nitride coating is often used

For surface treatment include all technical process of surface technology used in the production are applied a part to improve the surface properties.
The surface properties can be both functional (e.g. corrosion protection , wear protection , ...) and decorative (degree of gloss, color, ...) nature, or a combination of the two. The individual process comprises several processes that run one after the other in order to achieve the desired final property.

Important surface finishing processes

Application of layers (coatings)
- metallic coatings
  - Enamel coatings (e.g. hot-dip galvanizing )
  - Galvanic coatings (e.g. galvanic gold plating)
  - Plating (e.g. gold leaf coating)
  - PVD layers (e.g. metallized plastic)
  - Thermally sprayed layers (e.g. flame- sprayed zinc )

- ceramic coatings
  - Reaction layers (e.g. nitrided steel)
  - CVD layers (e.g. TiN ( titanium nitride ))
  - Thermally sprayed layers (e.g. plasma-sprayed Al ₂ O ₃ )

- amorphous coatings
  - Enamel (fused glass)

- organic coatings
  - Painting (e.g. powder painting )

Removing layers
- Pickling (e.g. hydrochloric acid )

Objectives of surface finishing

There are two possible overarching objectives, but they can also overlap:

Improvement of the functional properties
1. Corrosion protection (e.g. galvanizing and painting in automotive engineering)
2. Wear protection (e.g. hard material layers such as TiN on metal drills)
3. Prevention of contamination (e.g. coating with nanoparticles or plastic coating of food cans )

Improvement of decorative properties
1. Achieving a high degree of gloss (e.g. gold- plating of jewelry, nano-sealing )
2. Achieving certain colors (e.g. gilding jewelry)

Demarcation

Not for surface finishing includes mechanical machining process such as grinding or polishing, but as a process in a surface finishing process may be integrated.