METHOD AND APPARATUS FOR SPOT WELDING WORKPIECES PARTICULARLY MADE OF COPPER, COPPER ALLOYS, GOLD OR JEWELLERY MATERIALS USING LASER PULSES WITH GREEN WAVELENGTH

摘要

A laser welding method includes guiding laser pulses to a workpiece surface of workpieces and adjusting a power of the laser pulses according to a time pulse curve to spot weld the workpieces together. The time pulse curve has a first pulse section having a rising pulse flank for generating a melting temperature and subsequently a vaporization temperature in the workpieces, a second pulse section for melt bath generation having a vapor channel in the workpieces, a third pulse section having a pulse flank which initially drops vertically to at least ¾ of the power at an end of the second pulse section and subsequently drops more flatly for reversion of the vapor channel, and a fourth pulse section having a low pulse plateau and a level of between ⅓ and ¼ of the power at the end of the second pulse section for oscillation of the melt.