Bringing laser welding and laser marking in-house: A case study

Based in Ostermünchen near Munich, DHF Precision Mechanics counts well-known
medical device, electronics and aerospace engineering companies amongst its
customers. The company specialises in high-precision CNC-milled parts and
assemblies. Following 15 years of virtually continuous growth, the company now
operates 18 CNC machining centers and offers a service portfolio ranging from
prototype manufacturing to bulk production of
several 10.000 parts/year.

With fine precision plus a fast and flexible
response to customer requirements, DHF has established an enviable reputation in the market. The company regularly push the technical limits of CNC machining, such as the production of parts for electrical motors, which must be produced to micron tolerances. (DHF are based in Ostermünchen near Munich)

DHF has built up a comprehensive range of in-house capabilities including:
CAD/CAM design, machining various steel, titanium and aluminum alloys, CNC -
milling, surface finishing, assembly and quality assurance. This allows the company
to meet their key objective of quick response to customers’ individual requirements.

The production processes at DHF frequently comprise of welding, engraving and
marking. Welded components, especially those for medical device manufacturers,
must be perfect, not only free from porosity and cracks, but the surface finish must
also be immaculate to eliminate any chance of bacterial contamination. These criteria
also apply to deep engravings and markings. Contours must be free from burrs and
grooves. In addition, the marking process must not induce any material changes that
might promote surface corrosive action.
Until 2012, DHF had been outsourcing all laser material processing tasks.

Outsourcing however, not only significantly reduced production flexibility and speed
for certain parts, but also increased the complexity of logistics. Furthermore, the
annual outsourcing business volume had been approaching the six-digit range;
reason enough in itself to consider establishing an in-house laser material processing center.

Being new to laser technology, Fischbacher, Telser and Heilmann initially focused on
laser marking, as they expect laser welding to be much more difficult to control - at
least up to the point where they experienced laser welding first hand.

Once the potential benefits of in-house laser welding became clear, the managers at
DHF decided to incorporate a laser welding system in their investment planning.
The first step was to send samples to various laser manufacturers, asking for a live
demonstration of the laser welding process to determine its capabilities in relation to
weld quality and surface finish, two key requirements for the medical device
manufacturing industry. ROFIN-BAASEL sales manager Andreas Schöllhorn, based
at Starnberg, Munich, was able to prove that the laser could easily achieve the
process requirements, convincing the DHF managers to proceed.