Laseracoustic characterisation of multilayer systems (C-MEOW)
Increasing demands on quality and functionality can be observed in industrial manufacturing and surface technology, especially for functional multilayer systems. Cost-effective and high-quality multilayer surface treatment therefore requires a continous monitoring of the components. Currently, this monitoring is only possible non-destructively for single-layer systems. Multilayer coatings can only be characterized destructively.
The aim is to further develop a laser-acoustic measurement method for non-destructive and non-contact measurement of the mechanical properties of near-surface coatings in multilayer systems. The mechanical properties are determined by measuring the dispersive propagation characteristics of surface acoustic waves (SAW) over a wide frequency range. The non-contact excitation of the SAW is performed via the absorption of a focused pulse laser. The detection is performed by an interferometer with a photorefractive crystal. The focus of the development is on method selection and realization for later use in industrial applications.
The technology for laser excitation and detection of SAW will be further developed to enable industrial application. The measurement method is potentially inline-capable and can enable fast 100% testing. With the transfer of a basic investigation into industrial application, a contribution to quality assurance in surface technology and thus also a conservation of material resources is possible.