Use of femtosecond laser-induced breakdown spectroscopy (fs-LIBS) for micro-crack analysis on the surface

It is well-known that the initiation and propagation behaviour of small cracks is strongly influenced by the microstructure. In addition to the visible structure on the surface, in-depth information is essential for the evaluation of influencing factors. Investigations on micro-crack behaviour have been performed with intermetallic γ-based TiAl. Starter notches facilitate systematic studies as cracks initiate from notch tips. In this case artificial notches in the scale less than colony dimensions were prepared by femtosecond pulsed laser radiation, which causes no significant damage. After multistage tensile compression tests under increasing load, several small cracks were generated and analyzed in the SEM. Using femtosecond laser-induced breakdown spectroscopy (fs-LIBS) it was possible to analyze spectrochemically the surrounding microstructure of these micro-cracks and their propagation on the surface.