AUTOMOTIVE ENGINEERING EXPO Newsroom
Laserline, a specialist for industrial diode laser technology, will present the first high-power diode laser with a blue wavelength of 450 nm and 1 kW power in cw mode at AEE 2019. This diode laser based on GaN material enables the direct emission of 450 nm without further frequency doubling and thus a higher energy efficiency.
When deep welding copper with infrared lasers, a very high power density must be used due to the low absorption level of 5 %. Heat conduction welding is not possible at this wavelength. The process is prone to splashing and a rough seam surface.
With the new blue diode laser, the absorption of non-ferrous metals is seven to twenty times higher than that of infrared lasers, which enables controlled heat conduction welding of copper in particular. New production methods for electronic contacting, such as battery and accumulator production, benefit from this in particular.
Spot-in-Spot module for asymmetric seams
Laserline will also be showing its modified spot-in-spot module for welding asymmetrical seams at the AEE. The new tool offers an additional adjustment option that supports one-sided melting during thickness jumps, as is desirable for tailored welded blanks and fillet welds, for example. The inner spot is then responsible for the deep welding process and the seam root, the outer spot for the formation of the cross-section in the width, in particular for the connection to the thicker joining partner.
The spot-in-spot design
With the so-called "spot-in-spot" design, a larger spot is overlaid with a smaller spot. The power distribution between the inner and outer spot can be changed during the process and the position of the inner spot can be shifted in relation to the outer spot in the feed direction. In this way, the advantages of heat conduction welding, a smooth seam surface and low spatter formation are combined with those of deep welding, i.e. a high welding depth and welding speed.
The inner spot is shifted to the front area of the outer spot and the resulting smoothing effect of the larger spot is intensified. In addition to a better appearance of the seam, very straight seam edges can be created without edge notches. By adjusting the spot size and the power distribution, the seam cross section can also be optimized.
This module type is currently being tested by many OEMs and qualified in new processes. Series tests in the body outer skin have confirmed these advantages and in some cases even exceeded them. The larger spot also improves the gap bridging capability and thus the process window. In addition, this module allows the outer spot to be steplessly moved laterally to the feed direction via the robot.