Laser Treatment of Polycarbonate Surface: Influence of Laser Process Parameters on Surface Temperature Rise
S.Z. Shuja, S.B. Mansoor and B.S. Yilbas
Laser surface treatment offers considerable advantages over other conventional techniques in terms of precision of operation, fast processing, and low-cost. In laser surface processing, laser pulse intensity distribution, laser pulse frequency, and scanning speed play major roles on the maximum temperature increase at the substrate surface. Consequently, investigation into thermal response of the solid substrate to the laser heating pulse with different configuration of laser pulse parameter, laser scanning speed, and laser pulse frequency becomes essential. In the present study, numerical simulation is performed to explore thermal response of a polycarbonate sheet to the pulsed laser scanning. The laser parameters considered include laser pulse frequency, laser beam shape at the irradiated spot, and laser scanning velocity. Transient temperature distributions are computed using COMSOL software. The maps of maximum temperature and the shape of the heat affected regions are predicted in line with the consideration of the threshold glass temperature of polycarbonate (Tg = 420 K). The effects of varying each parameter is compared, and scaling trends are proposed. The present study provides useful insight into design and selection of laser treatment parameters for controlled surface modification of polymeric materials without exhaustive trial-and-error.
Keywords: Laser heating, polycarbonate, pulse parameters, temperature rise