Laser-ultrasonic inspection of surface-breaking tight cracks in metals using SAFT processing

Author

Lévesque, Daniel ; Ochiai, Makoto ; Blouin, Alain ; Talbot, Richard ; Fukumoto, Akira ; Monchalin, Jean-Pierre

Author_Institution

Ind. Mater. Inst., Nat. Res. Council of Canada, Boucherville, Que., Canada

Volume

1

fYear

2002

fDate

8-11 Oct. 2002

Firstpage

753

Abstract

A method is presented for imaging the detailed structure of surface-breaking tight cracks from the surface opposite to the cracks. The technique combines laser-ultrasonics and data processing with an improved version of the Fourier-domain Synthetic Aperture Focusing Technique (F-SAFT). The key point of this study is to use laser-generated shear waves, which interact very effectively with the crack roots. Ultrasonic images of the stress corrosion cracks, having depths of typically 0.5 mm. and widths of less than 0.05 mm, are successfully reconstructed and compared with results from liquid penetrant testing.

Keywords

elastic waves; image reconstruction; inspection; measurement by laser beam; metals; stainless steel; stress corrosion cracking; ultrasonic materials testing; Fourier-domain synthetic aperture focusing technique; SAFT processing; crack roots; data processing; image reconstruction; imaging; laser-generated shear waves; laser-ultrasonic inspection; laser-ultrasonics; metals; stainless steel; stress corrosion cracks; surface-breaking tight cracks; ultrasonic images; Diffraction; Focusing; Inspection; Laser noise; Optical materials; Optical pulse generation; Surface cracks; Surface emitting lasers; Surface reconstruction; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE

ISSN

1051-0117

Print_ISBN

0-7803-7582-3

Type

conf

DOI

10.1109/ULTSYM.2002.1193508

Filename

1193508