Product Code: ICAL09_M1004

Characterization of Morphology and Mechanical Properties of Glass Interior Irradiated by Femtosecond Laser
Authors:
Hongliang Wang, Columbia University Dept. of Mechanical Eng.; New York NY USA
Panjawat Kongsuwan, Columbia University Dept. of Mechanical Eng.; New York NY USA
Sinisa Vukelic, Columbia University Dept. of Mechanical Eng.; New York NY USA
Y. Lawrence Yao, Columbia University Dept. of Mechanical Eng.; New York NY USA
Presented at ICALEO 2009

Femtosecond laser pulses were focused in the interior of bulk fused silica specimen. Proper use of optical and laser processing parameters generated structural rearrangement of the material through a thermal accumulation mechanism, which governs the transmission welding process. The morphology of generated features was studied using differential interference contrast optical microscopy. The change in mechanical properties and the effect of laser processing parameters on mechanical responses were studied through employment of spatially resolved nanoindentation. The specimen was sectioned and nanoindents were applied at the cross-section to examine mechanical responses of the laser modified region. The ratio between hardness and Young's modulus was found and its influence on the stress intensity factor examined. Fracture toughness measurements are carried out to investigate benefits of the laser treatment on strength of the glass. In addition, the predictive capability of the morphology is developed via a finite element analysis. The numerical results in change of temperature and density were compared to the morphology and the experimental results for validation purpose.