Surface functionalization by laser-generated metal structures

Press release (Nr. XXIII) / 23.11.2012

Meanwhile the laser build-up welding technology is a well industrially established technique for highly precise coating tasks. Thanks to the IWS Dresden powder nozzles, the manufacturing of customized components can be realized up to a detail resolution within the double-digit micrometer range. At this year’s Euromold we presented a variety of powder nozzles and micro components.

Helical structures generated by high precision laser build-up welding
© Fraunhofer IWS Dresden

Helical structures generated by high precision laser build-up welding

COAX16 – miniaturized nozzle system for maximum accessibility
© Fraunhofer IWS Dresden

COAX16 – miniaturized nozzle system for maximum accessibility

Surface functionalization by laser generated structures
© Fraunhofer IWS Dresden

Surface functionalization by laser generated structures

According to the increasing industrial demands the IWS Dresden has optimized the laser build-up welding process towards minimum structure sizes. Maintaining the advantageous process characteristics, such as near net shape material deposition and low mixing of layer and substrate material, nearly any component geometries can be furnished with finest structures. Thanks to this unique development we could realize applications for the aerospace and tool industry as well as for the medical technology. All examples required a free three-dimensional structuring and the related functionalization of free form areas by precise metallic material deposition.

Additionally we are now able to fabricate complex micro volumes using our commercially available systems. By scaling down our process to smallest geometries we can fabricate a volume build-up in an almost non-porous and near net shape but extremely precise manner. Due to the low energy input we cause very few damages to the component to-be-coated but maintain the typically firm substrate adhesion. In addition to the required high precision, components are sometimes very difficult to access. That’s the reason why we developed very slim powder nozzle systems. The dimensions of the nozzle heads are throughout only 15 mm over a length of 100 mm. In combination with highly brilliant lasers we are able to generate meld baths of only few millimeters and weld bead widths of down to 30 µm. This fact opens a variety of new application fields.

In addition to already existing systems with deposition rates of about 15 kg metal powder per hour, the highly precise systems for very small sizes substantially complete the field of laser cladding technology. That means there is a factor of three power of ten between the smallest weld bead width (appr. 30 µm) and the biggest one (< 20 mm). Presently only the IWS is able to cover such a diversified working area for the laser build-up technology.