Fraunhofer Institute for Material and Beam Technology IWS
Fraunhofer Institute for Material and Beam Technology IWS

Procedures

Generative laser powder buildup welding

Surface coating and generated 3 D moulds at a cylindrical surface.
© Fraunhofer IWS
Surface coating and generated 3 D moulds at a cylindrical surface.
Metal leading edge made of TiAl6V4, generative fabrication in moving shielding gas chamber.
© Fraunhofer IWS
Metal leading edge made of TiAl6V4, generative fabrication in moving shielding gas chamber.

Based on 3D-CAD data models, 3D structures are generated for the direct fabrication, modification or repair of components. The component size is unlimited in this procedure and the smallest lateral resolution is 30 µm. Steels, nickel and cobalt alloys, titanium and aluminum lightweight materials and carbide composites can be processed in a defect-free manner. Currently IWS scientists focus their research into the development of intermetallic titanium aluminides and Ni-based high temperature materials.

Generative laser wire buildup welding

COAXwire optical equipment for deposition welding and additive manufacturing
© Fraunhofer IWS / Frank Höhler
COAXwire optical equipment for deposition welding and additive manufacturing

Compared to laser powder buildup welding, laser wire buildup welding bears significant advantages such as 100% material utilization, clean processes, high surface quality and a low chemical reactivity due to smaller specific surfaces.

Thanks to the novel IWS COAXwire processing head, wires can now also be processed independent from direction with high geometric degrees of freedom. The smallest lateral resolution is currently 600 µm.

Practically, all commercial wire feeders can be processed. Typical examples are tool and stainless steels, INCONEL625, INCONEL718, TiAl6V4, AlMg5 as well as bronze and Zn-based model alloys.

High performance deposition

Hybrid high power laser cladding process.
© Fraunhofer IWS
Hybrid high power laser cladding process.

For additive manufacturing technologies the direct single-step laser buildup welding procedure offers the advantages of high productivity, high rates, and high component quality. These advantages are achieved either by high laser performance or modern hybrid technologies. The IWS hybrid technologies are available as hot wire buildup welding and inductively supported laser powder buildup welding. The typical deposition rates are up to 14 kg/h metal alloys with raw part’s accuracies between 0.4 and 0.8 mm.

Laser milling combination

Additive-manufactured and partially finished moulding insert.
© Fraunhofer IWS
Additive-manufactured and partially finished moulding insert.
5-axis CNC machining center for buildup welding and finishing.
© Fraunhofer IWS
5-axis CNC machining center for buildup welding and finishing.

IWS modern CNC machining systems combine additive manufacturing processes and subtractive ablative procedures, such as milling. Very convenient solutions are for example standard milling machines, which become applicable for additive manufacturing processes by the integration of laser modules. The component size is determined by the workspace of the machine and the machinability is dependent on the available material spectrum. The final accuracy is no longer subject to the generative laser process, however, it is defined by the milling operation.