Scientists at the Fraunhofer Institute for Material and Beam Technology (IWS) in Dresden, Germany have developed a laser processing tool for wire cladding complex structures. The laser processing optics, CoaxWire, was presented at EuroMold in Frankfurt from 25 to 28 November.
CoaxWire is designed for applications demanding precise, two- and three-dimensional metal deposition. The optics split a collimated beam from a 4kW fibre or disk laser symmetrically into three partial beams and focus them in a circular spot. The set-up of the optical elements means the cladding wire can be fed directly into the centre of the laser-induced melt bath. This enables a complete directional independence for technical welding positions.
‘The advantages of wire as additional material have quickly convinced our industrial partners,’ Professor Nowotny at Fraunhofer IWS explained. ‘Independent from the component geometry, the filler wire is constantly utilised to 100 per cent as the material supply is independent from gravity.’
Compared to the powder cladding procedure this process is very clean, and both user- and environmentally-friendly. Furthermore, the wires are less likely to react with the atmosphere, which is an advantage for processing materials such as titanium and aluminium. Additionally, cored wires can be used, which enlarges the available range of alloys in the field of high-alloyed and hard materials.
The novel IWS laser wire coaxial processing optics are designed for use with commercial solid and cored wires, and compatible with standard wire suppliers. It includes collision and safety shut-downs to prevent damages in the case of malfunction. The compact design enables a simple integration into CNC machines and robot systems.
Current application fields range from repair of engines and turbines, coating functional surfaces on forms and tools, and direct additive manufacturing of metal components.