Surface treatments – find manufacturers and suppliers

Surface treatment includes all processes that specifically change the properties of surfaces in terms of corrosion resistance, wear resistance, electrical conductivity, adhesion, friction or visual appearance.

The treated surface often acts as a protective or functional layer and can make a significant contribution to the service life and quality of components.

Below you will find an overview of how surface treatment works and important types of surface treatment, their use, benefits and the challenges involved:

How surface treatment works:

The mode of operation is based on mechanically, chemically, thermally or electrochemically modifying the top layers of a material or applying additional coatings.
This improves properties in a targeted manner or adapts them to specific requirements.
Material properties such as hardness, roughness or chemical reactivity can be influenced or additional substances can be introduced into the surface.

Depending on the process, the treatment can be just a few micrometers deep or form a thicker layer.
The adhesion between the base material and the coating is also often specifically improved so that it remains permanently and robustly on the component.

Important types of surface treatment:

1. Mechanical processes
   These include grinding, polishing, blasting such as sandblasting, glass bead blasting or shot blasting and brushing.
   These methods improve roughness, gloss or stress states in the surface.
   They serve as preparation for further coatings or improve fatigue strength.
2. Chemical processes:
   Examples include pickling, passivation or chemical polishing.
   These processes remove oxide layers, clean the surface or create a thin, protective passive layer.
   Passivation prevents the formation of corrosion, particularly on stainless steel.
3. Galvanic coatings:
   Here, a metal layer is applied using electrolysis - e.g. galvanizing, chrome plating, nickel plating or gold plating.
   The aim is usually corrosion protection, wear resistance or a decorative effect.
4. Chemical deposition:
   Unlike electroplating, deposition works without an external current, e.g. electroless nickel plating (electroless nickel).
   These layers are uniform and can also coat complex geometries.
5. Thermochemical processes:
   These are processes such as case hardening, nitriding or carbonitriding, in which elements such as carbon or nitrogen diffuse into the surface layer.
   These processes can be used to make surfaces harder and more wear-resistant.
6. Thermal spraying processes:
   In processes such as flame spraying, arc spraying or plasma spraying, powdered or wire-like coating materials are melted and applied to the component.
   This creates thicker, wear-resistant or corrosion-resistant coatings.
7. PVD and CVD coatings:
   Physical vapor deposition (PVD) and chemical vapor deposition (CVD) are thin-film processes that produce very hard and wear-resistant coatings. Titanium nitride, chromium nitride or DLC coatings are typical. These are often used for tools or highly stressed components.
8. Organic coatings:
   These include painting, powder coating or the application of polymer coatings.
   The aim is usually corrosion protection, electrical insulation or decorative design.
   Powder coatings are particularly robust and environmentally friendly.

Use of surface treatment:

Surface treatments are essential in almost all industries:

1. Mechanical engineering:
Harder, wear-resistant surfaces increase the service life of gears, shafts or bearings.

2. Automotive engineering:
Galvanizing or phosphating protects body parts from corrosion, while PVD coatings harden engine parts.

3. Electrical engineering:
Gold plating of contacts ensures conductivity and corrosion protection.

4. Aerospace:
High-quality coatings prevent corrosion and wear in extreme conditions.

5. Medical technology:
Polished and passivated surfaces improve hygiene and biocompatibility in implants.

6. Construction industry:
Hot-dip galvanizing protects steel beams from rust for decades.

7. Packaging and food technology:
Smooth, chemically resistant surfaces are easier to clean and hygienic.

8. Decorative applications:
Chrome-plated or painted parts improve appearance and perceived value.

Advantages of surface treatment:

• Increased resistance to corrosion and oxidation
• Improved wear resistance and service life
• Reduced friction or targeted friction control
• Electrical conductivity or insulation depending on the application
• Improved adhesion properties (e.g. for adhesives)
• Optical refinement and color matching
• Hygienic and easy-to-clean surfaces

Challenges of surface treatment:

• Choosing the right process requires specialist knowledge and experience.
• Interactions with base materials must be taken into account.
• Preparation and cleaning are crucial for adhesion and quality.
• High demands on process control and reproducibility.
• Environmental impact (chemicals, emissions) must often be regulated and monitored.

Surface treatment is an indispensable part of modern production in order to prepare components functionally and economically for their use. It protects against corrosion and wear, optimizes technical properties and gives products an attractive appearance. A suitable selection, precise process management and careful quality control are decisive for the performance and durability of the end products.

Here you will find the most important aspects to consider when commissioning surface treatment.

When commissioning surface treatment, it is important to clearly define all technical requirements and framework conditions in advance. Careful planning and coordination with the service provider is crucial to ensure the quality, functionality and cost-effectiveness of the coated components.

• Before a surface treatment is commissioned, it should be absolutely clear what objective is to be achieved.
• Possible objectives include corrosion protection, wear protection, friction reduction, decorative finishing, electrical insulation or conductivity.
• Different processes are required depending on the intended use, so the desired result must be clearly described.
• Not every surface treatment is suitable for every material. The base material determines which processes are technically possible and economically viable.
• Before placing an order, it should be clarified whether the selected process is compatible with the material and whether it may require special pre-treatments.
• Errors in this step can lead to poor adhesion, cracks or other quality problems.
• A precise specification is essential. This includes details such as the desired coating thickness, the coating material, e.g. zinc, nickel, chrome, paint, the roughness or smoothness of the surface, permissible dimensional changes and defined requirements for corrosion protection classes or wear resistance. Unclear or incomplete information often leads to misunderstandings or unusable results.
• When selecting a coating service provider, attention should be paid to their experience, technical equipment and quality management.
• Important criteria are certifications, e.g. ISO 9001, industry-specific approvals for aviation, automotive or medical technology and the ability to deliver reproducible, documented results.
• The preparation of components is a critical success factor. oil, grease, oxides or particles must be completely removed before treatment. Errors in cleaning often lead to poor adhesion or uneven coatings.
• Before placing an order, it should be clarified who will be responsible for cleaning and which cleaning processes are planned.
• Many surface treatments change the component dimensions - either through application layers, e.g. paint, electroplating, PVD or through mechanical processing such as polishing or blasting.
• These effects must be taken into account during design and production. For components with tight tolerances, it is important to agree tolerance specifications and coating thicknesses with the coater in advance.
• The process must be tailored to the technical and economic requirements. For mass-produced items, simple galvanic processes or powder coatings may be appropriate, while thermal spraying or PVD coatings may be necessary for high-performance components.
• When placing an order, you should seek advice and ensure that the service provider has a good command of the appropriate process.
• Clear requirements for tests should be defined: for example, coating thickness measurement, adhesion tests, corrosion tests, e.g. salt spray testing, optical inspections or roughness measurement.
• Depending on the application, special standards or customer specifications may also be relevant. The service provider should be able to offer these tests and be prepared to issue test certificates.
• Close coordination with the coating company is crucial. For new or demanding components in particular, it is advisable to carry out preliminary tests or sample coatings and coordinate approvals. This is the only way to avoid later complaints or series problems.
• Components must be delivered in such a way that they are not damaged or soiled. Equally important is the protection of the coated surfaces during return transportation.
• Sensitive coatings require special packaging solutions or protective coatings, e.g. oils, films, to prevent damage or corrosion.
• Many surface treatments involve chemical processes and emissions. The service provider should comply with the applicable environmental and safety regulations.
• Strict legal restrictions may apply to certain processes, e.g. chromium (VI) coatings, so alternatives must be examined.

Commissioning a surface treatment is not a purely formal step, but a complex technical decision with a major impact on the functionality, durability and quality of the end product. Successful commissioning requires clear technical objectives, material and process knowledge, precise specifications and the selection of an experienced, qualified service provider. This is the only way to ensure that the treated components meet the required specifications reliably and over the long term.

You can commission surface treatment worldwide. Comprehensive information on surface treatment providers from all over the world can be found on Exportpages.