Original scientific paper

Laser-induced fractal cracking of tungsten surface

Stjepan Lugomer ; Ruđer Bošković Institute, POB 1016, 41001 Zagreb, Croatia
Mladen Stipančić ; Electrotechnical Faculty, University of Banja Luka, 78000 Banja Luka, Yugoslavia

Abstract

Catastrophic response of tungsten surface in the Q-switched Nd:YAG laser-material interaction, on the average power density scale between Q = 1.4 GW/cm2 and Q = 3.5 GW/cm2 appears in the two typical crack morphologies: the line brittle crack and the ductile triangular crack. Both of them are treated as the fractal objects. For the first one, the fractal dimension D = 1.60 was found, and the comparison with the model of mechanical breakdown of elastic materials by Louis et al., and with the deterministic model of Takayasu is given. For the second one, the cavitation mechanism of growth on the triple junction is suggested. Its fractal modeling is based on the Apollonian gasket model with the characteristic fractal dimension D ≈ 1.32. The crack velocity and the crack size have been estimated on the basis of the fracture mechanics model.

Keywords

Hrčak ID:

332045

URI

https://hrcak.srce.hr/332045

Publication date:

2.12.1991.

Article data in other languages: bosnian

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