Measurement of coating thickness in the testing laboratory

Which coating you choose for your components depends on various factors: Which environment are the parts used in? What environmental influences affect the parts? Reliable processes are absolutely vital to ensure that neither your component nor the environment come to any harm. One of these processes is layer thickness measurement, which Bossard carries out in accredited testing laboratories. Up to three layers on your metallic component are precisely measured with the aim of detecting any defects as early as possible and thus ensuring the quality of the components and that they are working properly.

What is a layer thickness measurement and which methods are available?

Coatings are found on a wide variety of components nowadays. Single or multiple coatings ensure that your components meet specific physical or chemical requirements. The applied layers not only need to have a certain hardness and adhesive strength; the coating’s thickness is also critical, too. If it is too thin, the entire coating can fail. This causes undesirable reactions between the surface and the environment. Coatings are found on a wide variety of components nowadays. Single or multiple coatings ensure that your components meet specific physical or chemical requirements. The applied layers not only need to have a certain hardness and adhesive strength; the coating’s thickness is also critical, too. If it is too thin, the entire coating can fail. This causes undesirable reactions between the surface and the environment.

To prevent this, you should have regular layer thickness measurements conducted in a testing laboratory. The layer thickness is measured, you learn exactly how thick a coating is and you therefore obtain information about the quality of your components.

During a layer thickness measurement, a distinction is made between a number of destructive and non-destructive measurement methods, including:

• the optical layer thickness measurement
• the calotte grinding process
• X-ray spectroscopy
• the X-ray fluorescence (XRF) analysis
• the microwave test
• the eddy current method
• the magnetic-inductive method
• the ultrasonic test
• the cross-sectioning method

Layer thickness measurement 101

Which measurement method is most suitable for measuring your components’ layer thickness usually depends on the base material and its coating. For example, when dealing with multi-coated metallic components, X-ray fluorescence (XRF) analysis can provide precise results on layer thicknesses and compositions. When using this measurement method, a sample is exposed to targeted X-rays. The radiation energy causes the electrons in the atom to leave their original position and be replaced by atoms from higher layers. The material subsequently gives off characteristic X-ray fluorescence radiation. The experts measure this radiation and determine the thickness of up to three different layers.

In addition to XRF, layer thicknesses can also be measured with:

• the magnetic-inductive method for measuring non-magnetic coatings on magnetic substrates
• the eddy current method for measuring insulating layers on non-ferrous metals
• the ultrasonic method for measuring layer thicknesses on non-metallic base materials or layer systems

Bossard – precise metal layer thickness measurement in the testing laboratory

Bossard focuses on X-ray fluorescence analysis in its accredited testing laboratories. It is a non-destructive method that provides precise and targeted layer thickness measurements despite the short time it takes. Furthermore, the components’ geometry does not play a role in XRF.

In our testing laboratories, we therefore test the required protective metal layer thicknesses of:

• components with up to three layers; and
• coatings consisting of zinc, nickel, chrome, zinc flake, gold, silver and many more metals besides.

Bossard has testing laboratories around the world that are accredited to ISO 17025 and relies on a quality management system that is certified to ISO 9001:2015. We employ highly qualified, experienced specialists who will be happy to advise you on layer thickness measurement and assist you with their extensive expertise.

Contact our experts to find out more about Bossard’s Expert Test Services. We look forward to hearing from you!

Contact

Expert Education
Learn about the essentials and secrets of fastenings in our seminars and e-learning courses

Expert Teardown
Identify the best fastening solution and cost saving potential for you

Expert Design
Design your best product with a wide range of technical information and tools

Expert Walk
Study your fasteners and tools in use, we determine how to proceed leaner and smarter

Expert Assortment Analysis
Reduce TCO by identifying opportunities for fastener rationalization