jointly by MAHLE, sports car manufacturer Porsche and mechanical engineering
company Trumpf, the high-performance aluminium pistons were successfully tested
on the engine test bench for Porsche’s 911 GT2 RS sports car
part of a cooperation with sports car manufacturer Porsche and mechanical
engineering company Trumpf, MAHLE - the auto component manufacturer - has
produced high-performance aluminium pistons using 3D printing techniques for
the first time. The pistons were successfully tested on the engine test bench
for Porsche’s 911 GT2 RS sports car. Whereas standard forged pistons have
reached the limits of their performance potential, it is conceivable that the
power of the 700 HP Porsche engine could be boosted by 30 HP with an associated
increase in efficiency. MAHLE is specifically developing its expertise in 3D
printing, so that, in the future, it will also be able to support its customers
in the field of alternative drives, including electric drives, by supplying
suitable components for drives, thermal management, and mechatronics promptly.
results of the project confirm the great potential of 3D printing and
demonstrate MAHLE’s particular competence in the field of high-performance
small and limited runs and in relation to prototyping and aftermarket,” said Dr
Martin Berger, Head of Corporate Research and Advanced Engineering at MAHLE.
Ickinger, Project Manager at Porsche, commented, “Thanks to the close
cooperation of everyone involved, we were able to demonstrate the potential of
additive manufacturing in our top-of-the-line high-performance sports car, the
Porsche 911 GT2 RS, thus clearing the way for its use in future drives. In terms
of technology, this is the start of a new chapter for us, which opens up
completely new possibilities in design and production.”
Rübling, Project Manager at Trumpf, also sees big opportunities for 3D printing
in future manufacturing processes. “The project illustrates how 3D printing can
be used to further improve components whose performance potential has already
been exhausted by decades of development. This will benefit many other
industries, such as aerospace and energy.”
bionic design reduces piston weight and increases maximum engine speed. The new
process presents the option of implementing a so-called bionic design. In this
approach, which mimics natural structures such as the human skeleton, material
is added only in loaded areas, with the structure of the piston being adapted
to the load. It saves material and has the potential to make the 3D printed
piston up to 20 percent lighter than its conventionally manufactured
counterpart while increasing rigidity.
addition, the developers at MAHLE have introduced an optimally positioned and
specially shaped cooling gallery near the piston rings. This design is based on
MAHLE’s many years of experience with thermal processes on the piston and is
only possible using 3D printing. The cooling gallery reduces the temperature
load at the so-called top land, a particularly stressed part of the piston,
thus optimizing combustion and paving the way for higher maximum engine speeds.
new production process is based on a special aluminium alloy developed by MAHLE
with a long history of successful use in cast pistons. The alloy is atomized
into a fine powder and then printed in a process known as laser metal fusion
(LMF). A laser beam melts the powder to the desired layer thickness, followed by
the application of a new layer on top, thereby building the piston up one layer
at a time. Using this method, 3D printing specialist Trumpf produces piston
blanks made up of approximately 1,200 layers in around 12 hours.
project involved multiple challenges. From the design of the piston through the
specification of the material and the development of the appropriate printing
parameters, we had to make many fine adjustments to achieve the optimum result.
We have now not only mastered the technical side of things, but can also assess
how the method can be embedded into existing manufacturing processes,” explained
Volker Schall, Head of Product Design in Advanced Engineering at MAHLE.
quality confirmed in stringent test run
piston blank is then finished, measured, and tested at MAHLE and must meet the
same strict standards as a conventionally manufactured part. Special attention
is paid to the central area of the piston - known as the skirt - and the point
at which it connects with the conrod -the pin bore. These areas are subjected
to skirt pulsing and tear-off tests; MAHLE’s engineers can thus simulate the
loads that will occur during future operation.
addition to cutting open pistons for analysis, project partner Zeiss carried
out numerous non-destructive tests using procedures including CT scanning, 3D
scanning, and microscopy. The results show that the printed piston achieves the
same high-quality standard as a conventionally manufactured production piston.
When it came to practical testing, six pistons were fitted in the engine of the
Porsche 911 GT2 RS, and the drive unit successfully completed 200 hours of
endurance testing under the toughest conditions on the test bench. This
comprised around 6,000 km at an average speed of 250 km/h including refueling
stops, and around 135 hours at full load. The test run also included 25 hours
of motoring load, ie, the simulated overrun mode of a vehicle.
charge air cooler for even greater efficiency
evidence of the advantages of 3D printing is provided by an additional charge
air cooler, again developed as part of the joint project with Porsche and
Trumpf. Hidden in an air pipe between the turbo and the original charge air
cooler, this additional component benefits from a significantly larger heat
transfer surface thanks to the possibilities opened up by 3D printing. This
allows flow control and cooling to be optimized, resulting in cooler intake
air, increased engine performance, and lower fuel consumption.
to expand its competence in 3D printing
is a leading international development partner and supplier to the automotive
industry as well as a pioneer for the mobility of the future. The group’s
product portfolio addresses all the crucial issues relating to the powertrain
and air conditioning technology - both for drives with combustion engines and
for e-mobility. In 2019, the technology group generated sales of approximately Euro
12.0 billion with more than 77,000 employees and is represented in over 30
countries with 160 production locations.
is set to harness the potential of new production processes, such as 3D
printing, for further projects and aims to expand its competence in this area
specifically. Shorter development and production times present a great advantage.
This is particularly true when it comes to new technologies such as e mobility,
where thermal management components with complex structures are needed to
provide cooling and air conditioning in electric vehicles, motor or
transmission housings, and battery systems. Further examples include optimized
components in the periphery of the motor, such as air pathways, filter
housings, and oil management components.
of need have also been identified with regard to the development of small lots
and the production of discontinued components to supply the aftermarket for
historic vehicles. Other promising fields of application involve rapid
prototyping, i.e., the quick construction of parts for testing, and reverse
engineering - the reproduction of components from a 3D scan.