LASER MICRO-WELDING OF THIN SHEETS USING NANOSECOND LASER PULSES

Resumo

This work presents a new method for micro-welding thin sheets using a high repetition rate Cu-HyBrID laser emitting intense nanoseconds pulses. An experimental study of micro-welding process using short laser pulses was conducted on stainless steel (AISI 304) thin sheets with thickness of 100 ?m. A theoretical model was developed to explain the role of the laser pulses emitted at high repetition rates on the micro-welding process. Although the intensity laser pulses exceed the threshold to perforate the thin sheets, the model results shown that the geometry of drilled hole can be controlled in a way that the vapor and liquid remains trapped and further condensate on the cavity inner wall allowing the welding of the sheets. In those controlled experimental conditions the thin sheets were welded using 20 watts of laser average power which is much lower than the power used in CW laser welding.