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Coating and Surface Engineering

Better environmental sustainability and reduced life-cycle costs are important drivers in industry today. Surface engineering is a valuable tool in achieving both of these by facilitating optimal materials selection and innovative product design.

Surface Engineering

There are a wide range of surface engineering processes. At one end of the scale, ion implantation, nitriding and aluminising affect the chemistry and properties of only a thin surface layer of the substrate, by modifying the existing surface to a depth of 0.001–1.0mm. At the other end of the scale are weld hardfacings and other cladding processes. Typically 1–20mm thick, these are usually used for wear or corrosion resistance and repairing damaged parts.

Between these two extremes are deposition processes such as physical vapour deposition (PVD), chemical vapour deposition (CVD), anodising, laser processing, thermal spraying, cold spraying, and liquid deposition methods.


Coating application and performance characteristics are heavily dependent on composition and processing parameters. Coatings ranging from purely ceramic to purely organic in character have very different properties, but can provide critical benefits to the component.

Selection of the most appropriate coating type and deposition method requires an understanding of the operational requirements, together with the candidate application methods and supply chain considerations. Testing and validation of the surface is essential to ensure that the necessary fitness-for-purpose characteristics have been achieved, and comparison between candidate systems against established or developing standards has been undertaken.

Materials Infographic
Surface Modification Infographic
Process Infographic
Characterisation Infographic

TWI’s expertise

TWI possesses the capability, experience and facilities to allow the most appropriate coating methods and materials to be selected and validated from the wide range of options available.

We have been actively involved in fundamental research and applications development to help industry meet the dual challenges of improving the performance characteristics and durability of components and address sustainability challenges, such as finding alternative coatings to those being phased out due to environmental or health concerns. We have also assisted in the development of restoration/repair techniques for high-value parts in many industry sectors, including poweraerospace and oil and gas.

Examples of areas where we are working confidentially to address our Members' requirements include:

  • New anti-microbial coatings for the healthcare sector
  • Printable transparent conducting coatings
  • New low-cost anti-reflective coatings
  • Selection of environmentally responsible coatings for high-value consumer goods
  • High-performance hardcoats for glazing applications

Application of a wear resistant coating

Surface finishing using the laser metal disposition (LMD) process

A novel super hydrophobic coating developed at TWI

The TWI coating team developed the coating using functionalised silica nanoparticles (Water contact angle of 150° on glass)

Robot mounted HVOF spraying of an automotive cylinder head

Thermal spraying can be used to deposit metals, cermets (such as WC-Co), ceramics, polymers in layers typically 60 μm to 10 mm thick, for a wide range of engineering applications

In addition to fundamental and applied research, TWI also provides consultancy, materials selection and failure analysis services. We offer impartial specialist expertise and are uniquely situated to develop new coating compositions, formulations, or pre-treatments for coatings that span the full range of compositions and deposition methods.

Selection of appropriate coatings can drive down costs and lead to improvements in application and operational performance.

There is a wide range of options available for immediate use and as the basis for new products. Identification of the coating system that is fit-for-purpose is essential to achieve the desired result.

TWI has researched coatings for applications in the following sectors:

For more information please email: