Non-destructive characterisation by means of ultrasonics of radial cracks resulting from Vickers indentations in reaction-bonded silicon nitrideFunded under: JRC-ADVMAT 1C
Ultrasonics is one of the most promising techniques for the non-destructive testing of engineering ceramics, especially for the characterisation of cracks. The detection and sizing of radial cracks resulting from Vickers indentations in Reaction-Bonded Silicon Nitride (RBSN) by means of ultrasonics at relatively low frequencies (30 MHz) are discussed. The crack lengths vary between 100 micron and 600 micron. Bulk shear waves and surface waves are used to obtain the C-scans. The interpretation of the images obtained is complicated by the presence of the indentation. Two methods are used to size the radial cracks: the -6 dB amplitude drop and the relationship between maximum amplitude of the echo and the reflective crack surface. The results obtained are discussed and compared with the sizes measured by optical microscopy.
Bibliographic Reference: EUR 13535 EN (1991) 30 pp., FS, ECU 6
Record Number: 199210313 / Last updated on: 1994-12-02
Original language: en
Available languages: en