Main fields of work

• Joining of steel (high-strength steel sheets and construction steels, tool steel etc.)
• Joining of thin sheets
• Joining oflight alloy components
• Production of mixed compounds inclduding different material types
• Development and characterization of combined and hybrid procesess
• Development of process technologies and special processing heads for hand guided material systems
• Analysis and modification regarding structure and  mechanical propoerties of produced joints
• Numerical simulation of processes and component propoerties

Sheet metal and steel processing is one of the major areas of the Joining and Cutting of Metals Group. Nonferrous metals in general, but also light metals are another focus area. These materials still have a great potential for reducing the weight and fuel consumption in vehicles and other fields of engineering. Also, state-of-the-art high-strength steels open up further opportunities for light weight construction. Technically mature and fully-developed processing techniques are a prerequisite for the market success of these materials.

Both precise temperature control and appropriate sensorics are of great importance.Using eddy current technology, it is possible to locate the zero gap with a precision of a few hundredths of millimeters which is particularly important for welding construction parts with highly-precised edges. These construction parts must be positioned and welded with maximum precision to ensure a smooth production process. In order to achieve an optimum insensitiveness to tolerances, we are developing an eddy current sensor which recognizes the abutting edge as a defect of the construction part and can track the focal spot in case of a drifting of the workpiece.

Here, the CNC control is not involved and due to the self-contained positioning axis the process head can be integrated in any system without no modifications.

In combination with inductive energy sources, the laser can not only join materials more rapidly and deeper, but can also join materials that are normally difficult to weld. The laser has a positive effect on the welding process, both in terms of energy input and temperature distribution. As a result optimum cooling conditions are achieved: undesirable are microstructures avoided and the welding speed can be increased by 20 percent. If in addition the part is squenched after the welding process, hardened functional surfaces for e.g. camshafts can be generated.

Very often SME decide against the use of a laser in production because of a lack of financial investment resources and insufficient machine utilization. Also, many users do not know the power limits of the available systems. A database that compares pulsed and continuous wave laser operation is currently being developed at LZH. The database will also include information about the characteristics of the welding seams.

Within the scope of the discussion about reducing CO2 emissions, the automotive industry increasingly considers to use steel/high-strength steel aluminum compounds. Both put high demands on the applied joining processes. The advantage of the laser is the low heat input. Also, the mechanical properties of laser-welded high-strength steels are only subject to a negative effect in a very small and restricted area. For laser-solded joints the heat input can even be reduced to an extent that the parts do not melt. This not only allows for joining steel, but also for joining aluminum and steel and thus a lower weight of the construction part.