4.1.2 An optical sensor system for characterization of ceramics based on laser speckle photometry

Event
20. GMA/ITG-Fachtagung Sensoren und Messsysteme 2019
2019-06-25 - 2019-06-26
Nürnberg, Germany
Chapter
4.1 Werkstoffprüfung und -charakterisierung 1
Author(s)
L. Chen, U. Cikalova, B. Bendjus, S. Muench, M. Roellig - Fraunhofer-Institut für Keramische Technologien und Systeme IKTS, Dresden (Deutschland)
Pages
297 - 303
DOI
10.5162/sensoren2019/4.1.2
ISBN
978-3-9819376-0-2
Price
free

Abstract

Advanced ceramic components are widely used in the industrial applications, e.g. substrates of power electronic modules, and electrolytes of new generation batteries. As a brittle material, the crack propagation is very sensitive to the stress distribution of ceramics. Existing defects under extreme stress condition will lead to the functional failures of the whole component. In order to avoid the crack initiation and propagation, and guarantee a good quality state of ceramic products, stress condition and defects should be monitored and detected. In this paper, an optical non-destructive testing method - Laser Speckle Photometry (LSP) will be demonstrated to determine mechanical stresses in ceramic substrates and detect defects in ceramic products for the industrial applications. The LSP method is based on the analysis of a time resolved speckle dynamics which is activated by an external excitation. The speckle signal can be correlated to the external introduced signal and further be related to our targeting parameters mechanical stress and existing defects in the ceramics. The preliminary results of LSP has shown its great potential for non-destructive characterization of ceramics in terms of stress monitoring and defect detection.

Download