FRACTURE-BEHAVIOR OF FUSED QUARTZ WITH LASER-INDUCED INTERNAL FLAWS

Citation
Yz. Li et al., FRACTURE-BEHAVIOR OF FUSED QUARTZ WITH LASER-INDUCED INTERNAL FLAWS, Journal of materials research, 9(7), 1994, pp. 1780-1788
Citations number
23
Categorie Soggetti
Material Science
ISSN journal
08842914
Volume
9
Issue
7
Year of publication
1994
Pages
1780 - 1788
Database
ISI
SICI code
0884-2914(1994)9:7<1780:FOFQWL>2.0.ZU;2-X
Abstract
Pulsed-laser light was used to generate internal flaws in fused quartz . The size of the flaw produced was proportional to the amount of lase r pulse energy above a threshold value of 2.5 mJ. Specimens of differe nt flaw sizes were tested at room temperature under four-point bending . The bending strength decreased as the flaw size increased, and a Gri ffith relationship was established between the lateral flaw size and t he critical stress at the flaw tip. Characteristic demarcation lines w ere observed on the fracture surfaces of specimens with a flaw size gr eater than 0.25 mm. It is suggested that the formation of the demarcat ion line is caused by a discontinuous change of stress intensity in th e dynamic process of the crack propagation.