Influence of processing parameters on the quality of titanium-coated glass welded by nanosecond pulse laser

Glass welding has important application value. In order to efficiently obtain strong and transparent glass welded joints, a 30nmTi coating was added as an absorption layer between the two glasses, and a nanosecond pulse laser with a Galvo scanning system was employed. The effects of processing parameters including laser power (3–10 W), scanning speed (20–400 mm/s), and repetition frequency (20–80 kHz) on the transmittance and tensile strength of joints were discussed systematically. The effect of laser power is the most significant. The transmittance and tensile strength first increases as the laser power increases, followed by a decrease. The optimum laser power, scanning speed, and repetition frequency was 8 W, 100 mm/s, 20 kHz, respectively. The average transmittance was 83.6% and the tensile strength reached 38.07 MPa. The Micrographs of the welding interface and the fracture surface obtained by a confocal laser scanning microscope (CLSM) were used to discuss the welding mechanism with different gap sizes and different processing parameters. When the gap and processing parameters are appropriate, the irradiated titanium film and nearby glass will melt and form a continuous molten pool, through which the glass is stably connected together. The welded joint is uniform and tight, and its fracture surface extends into the glass substrates of several hundred microns.