White Papers


White Papers

Plagiarism protection of metallic workpieces

Identification of workpieces

The secure identification and authentication of workpieces plays an increasing role in the production of metallic workpieces and the components and aggregates based on them. The reasons for this are:

  • Traceability of parts / workpieces within the scope of quality management
  • Differentiation of the same workpieces from different manufacturing processes
  • Proof of date of manufacture for warranty purposes
  • Detection of OEM parts or non-authentication of plagiarisms

Inspired by the security features of banknotes, we have developed a solution for metallic surfaces.

Luminescent Nano Pigments

Luminescent nano pigments (LNP) are inorganic ceramic particles produced in grain sizes from 0.1 to 5 * 10-6 m. The particles are produced in a variety of sizes. The very fine particles are mixed with elements from the group of rare earths (periodic table) in such a way that they achieve the desired luminescent properties. The particles are very hard, have a high resistance against acids and bases, are non-toxic, inert and their melting point is far above 2000°C.  When irradiating LNP with wavelengths of approx. 1,000 nm (IR laser, invisible), the LNPs emit light in the optically visible range depending on their elemental composition; hence the term "up converting phosphors". Available colors are green, red and blue. The wavelengths and decay behavior of the emission depend on the elemental composition. Combinations of different wavelengths (colors) can also be produced by mixing production batches. Thus each production batch of LNPs receives a characteristic unique emission spectrum regarding frequency, intensity and decay behavior of the luminescence. The emissions are caused by the quantum physical effect of "upconverting phosphorus", in which several photons of the long-wave irradiated IR light lead to the emission of a photon of visible light (non-linear-optics).


State of the art

Many metallic workpieces are currently not marked at all, but are identified exclusively via the secondary products. This can be a stamped number or a simple type plate. Depending on the field of application, important parts are provided with branded or stamped numbers that refer to the origin and manufacture of the parts. These numbers can only be identified independently of the simple counterfeit by corresponding analyses of reserve samples.

Development goals

  • Sustainable application
    Methods for the sustainable application of LNP to metallic surfaces are to be developed, which will allow the workpiece to be clearly identified as a metallic batch even after further processing steps.
  • Readout / Identification
    Furthermore, the methods for reading out and thus identifying the LNP are to be improved so that it can also be used reliably on a shiny metallic surface.
[Translate to English:] Wellenlänge Diagramm
[Translate to English:] LNP Ni Map 1000 Grad
[Translate to English:] Sensorinstrument mit IR Filter
[Translate to English:] Sensorinstrument mit IR Filter

Society for Materials Testing
Ensuring quality | Accompanying development | Analyzing damage | Passing on knowledge

GWP Gesellschaft für Werkstoffprüfung mbH
Georg-Wimmer-Ring 25
85604 Zorneding/München

Tel. +49 8106 994110
Fax +49 8106 994111

Handelsregister München
HRB 53245
USt.-IdNr. DE131179893

General Manager
Dr. Julius Nickl