Page 20 - 3DA Mag N° February2018 -EN+

CASE STUDY

This brake caliper is the largest
titanium functional component
produced by 3-D printing in the
world – developed by Bugatti.
The photo shows the caliper
together with pistons and pads.

Heat treatment is carried out in a furnace where the machined in a five-axis milling machine which takes
brake caliper is exposed to an initial temperature of another 11 hours to complete its work.
700°C, falling to 100°C in the course of the process, in
order to eliminate residual stress and to ensure dimen- The result
sional stability. Finally, the supporting structures are The result is a delicately shaped component with wall
removed and the component is separated from the tray. thicknesses between a minimum of only one millimetre
In the next production stage, the surface is smoothed in and a maximum of four millimetres.
a combined mechanical, physical and chemical process
which drastically improves its fatigue strength, i.e. the “It was a very moving moment for the team when we held
long-term durability of the component in later vehicle our first titanium brake caliper from the 3D printer in our
operation. Finally, the contours of functional surfaces, hands,” Frank Götzke remembers. “In terms of volume,
such as the piston contact surfaces or threads, are this is the largest functional component produced from
titanium by additive manufacturing methods. Everyone
who looks at the part is surprised at how light it is –
despite its large size. Technically, this is an extremely
impressive brake caliper, and it also looks great.”

The first trials for use in production vehicles are due to
be held in the first half of the year; the time schedule
is still to be finalized. At that stage, the engineer
promises that it will be possible to considerably shorten
production times, especially for machining.
The 3D printed titanium brake caliper is only one
example of Bugatti’s current research and development
work. The board only weighs 0.4 kg, half the weight of
a conventional die-cast lightweight aluminium board,
without any reduction in rigidity. But that is another
story.

Prof. Dr.-Ing. Claus Emmelmann, formerly Managing
Director of Laser Zentrum Nord and now, after its
incorporation in the Fraunhofer research organization,
Head of the Fraunhofer Institute for Additive Production
Technologies (Fraunhofer IAPT)

Magazine / February 2018