J. Walter
M. Hustedt
C. Hennigs
J. Stein
S. Barcikowski

Emission data and costs for environmental measures during laser joining of metals

International Symposium on Laser Precision Microfabrication (LPM)
7.-10. Juni
Stuttgart
2010
Type: Konferenzbeitrag
Abstract
Laser welding and soldering are important joining p rocesses in the automotive industry. Typical examples are the production of the car body of the VW Golf or the automatic gearbox of the Mercedes-Benz A-Class. Furthermore, there is a gene ral trend to increase the use of lightweight materials (e.g. Mg, Al, alloys), and to combine dif ferent metallic materials to produce complex components (e.g. in tailored blanks). In order to e nsure good practices with regard to occupational health and safety as well as environmental issues, laser joining processes have to be analyzed in detail. Avoiding and controlling emission products caused by laser processing of metals or metal composites is an important task in this context. Ty pically, costs for environmental measures re- present a significant percentage of the total manuf acturing costs related to a laser process. In this work, emission measurements of several la ser welding and soldering processes for metal sheets from steel and brass are reported. Different steel grades and surface treatments of the metal sheets have been taken into account: pure, zinc-coa ted, PTFE-coated, oiled, cold cleaner residues. The hazardous potential of these processes has been assessed by means of analyzing the specific emissions with respect to the relevant threshold li mit values (TLVs). Based on the experimental results, the processes have been classified accordi ng to measures which are required by environ- mental legislation. Finally, a cost calculation for measures related to emission capturing is presente d. It has been shown that these environmental measures are manageable for all industrial laser pro- cesses regarded here, and the costs for these measu res remain acceptable, i.e. in many cases below 8 \% of the total processing costs. The results are made permanently available in an interactive internet database. Using this database, the plannin g of appropriate exhaust systems for laser welding and soldering is facilitated significantly.