FRAUNHOFER INSTITUTE FOR MANUFACTURING TECHNOLOGY
A N D A D VA N C E D M AT E R I A L S I F A M , B R A N C H L A B D R E S D E N
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1 Sandwich element for light-
weight construction 2 Hollow sphere structure for
reinforcement in an
automobile
LIGHTWEIGHT CONSTRUCTION
BY LOCAL REINFORCEMENT WITH
HOLLOW SPHERE STRUCTURES
Fraunhofer Institute for
In order to allow for the increased requi-
Such reinforcements by metal hollow
Manufacturing Technology
rements of modern lightweight concepts,
sphere structures exhibit a locally enhanced
and Advanced Materials IFAM a mixture of optimal materials at the right
strength and prevention from collapse of
Branch Lab Dresden
position is needed. At the same time,
critical areas.
additional functions need to be integrated
Winterbergstrasse 28
into the components. The Fraunhofer
Due to the low densities of the hollow
01277 Dresden I Germany
Institute for Manufacturing Technology
sphere structures in the range of 0.3 up to
and Advanced Materials IFAM in Dresden
0.8 g/cm³, the mass reduction of the lower
develops cellular metal materials which
wall thicknesses of the profiles exceeds the
Contact
can be adjusted to various requirements as
mass gain of the reinforcements in most
Dr.-Ing. Peter Quadbeck
core materials in sandwich structures and
of the cases. The reinforcement is realized
Phone +49 351 2537 372
profiles, and which can take over additional
by inserts or by filling with sintered and
Fax
functions.
adhesion-coated single hollow spheres.
Considerable weight reduction of profiles
Picture 2 gives an example of how such a
and sandwiches is possible if the realization
filling for the reinforcement of a B-pillar of
of local reinforcement allows for the
an automobile may be integrated.
+49 351 2537 399
E-Mail: Peter.Quadbeck
@ifam-dd.fraunhofer.de
www.ifam-dd.fraunhofer.de
reduction of wall thicknesses.
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• Materials evaluation with respect to By adjusting the density and the basic
This enables the improvement of the
material of the hollow sphere structure the
absorption of structure-borne sound
strength, energy absorption, damping, needed mechanical, thermal and corrosive
as well as the resonance frequencies of
corrosion resistance and application at
properties are tailored. Furthermore, by
components. The powder metallurgical
higher temperatures.
adjusting the kinetic energy absorption of
manufacturing technology being deve-
the hollow sphere structure the required
loped at Fraunhofer IFAM Dresden at
volume of the crash absorbers may be
present is being transferred to an industrial
determined. The required volume of such
fabrication. Thus, the manufacturing of
parts may be lowered considerably in
larger quantities will be possible in the
comparison to an unfilled absorber.
near future.
• Technology development of
- Loading-adapted cores in sandwich structures
- High kinetic energy absorption (crash,
high speed deformation)
- Damping of structure-borne sound
- Bonding technologies (sintering,
soldering, adhesive bonding)
Hollow metal spheres can be filled with
fine ceramic particles. Thus, the material
R&D Services
- Accredited testing lab (powder
at ultralow weight. As an example, at a
density of 1.5 g/cm³ the damping factor
• Prototype and small series production
• Materials and component testing
achieves enormous damping capabilities
• Application oriented studies of
analysis, mechanical testing)
of the new material exceeds the damping
questions related to materials and
- Damping analysis
factor of aluminium by a factor of 100.
manufacturing
- Corrosion studies
- High temperature characterization
• Know-how transfer for industrial production
filled profile
Stress
1 Snap shot of a crash test with hollow sphere structures in
order to demonstrate the high energy absorption capability
2 Components filled with hollow unfilled profile
sphere structures before and
after crash test
Compression
Comparison of a profile filled with hollow sphere structures and an unfilled profile
 www.motor-kompakt.de (2)
Fraunhofer IFAM Dresden (1,3,4)