Federal-Mogul Powertrain, a
division of Federal-Mogul Holdings Corporation of the US has announced that it
has developed a new premium diesel piston aluminium alloy, called DuraForm-G91.
In benchmarking tests, the new alloy – which will be on display at the IAA show
in September – provides between three and five times the component life of
established as-cast materials in modern, highly loaded, diesel engines. The
increased strength of the new material also supports higher mechanical loads,
allowing engines to operate at higher specific power and more efficiently.
The enhanced alloy properties facilitate
piston designs with a lower compression height and reduced mass. The resulting
benefits of less reciprocating mass and smaller, lighter cylinder blocks
contribute to vehicle CO2 emissions reduction. “This is an example of the
enabling technologies developed by Federal-Mogul Powertrain that help our
customers to make each new engine generation more compact, lighter and with a
smaller carbon footprint than its predecessor,” said Gian Maria Olivetti, Chief
Technology Officer, Federal-Mogul Powertrain. “With our materials scientists at
the technological forefront of the industry, we are committed to developing
advanced new concepts for both aluminium and steel-based pistons for diesel
vehicles, offering perfect fit solutions for the various needs of our customers,
” added Olivetti.
DuraForm-G91’s composition delivers increased
fatigue strength, particularly in the high temperature range typically
associated with highly loaded diesel pistons. “The improved silicon and
intermetallic morphology provides a microstructure with increased resistance to
complex thermomechanical loading, while maintaining the required
thermo-physical properties, such as expansion, density and thermal
conductivity,” explained Dr. Frank T. H. Dörnenburg, Director of Technology,
Global Pistons, Federal-Mogul Powertrain.
DuraForm-G91 has been developed using advanced
testing techniques that shorten the validation period to production readiness.
“We have employed specially designed accelerated base engine tests combined
with ‘engine-like’ rig testing procedures,” said Roman Morgenstern, Specialist,
Material Development and Characterization, Global Pistons, Federal-Mogul
Powertrain, adding that “Engine-like rig
testing combines thermomechanical fatigue (TMF) with high cycle mechanical
fatigue (HCMF), which directly reflects the fatigue-critical load conditions
seen by automotive diesel pistons in the engine.”
In both engine testing and TMF-HCMF testing,
DuraForm-G91 demonstrated three to five times the fatigue life of current
as-cast alloys. During isothermal high cycle mechanical fatigue testing at
temperatures above 350°C, the improvement was even more pronounced, at over
eight times the life.
Additional engine testing has
shown wear rates equal to those of the best current aluminium-silicon based
piston materials. Extensive casting development trials have been carried out to
deliver consistently high material integrity and optimize the casting
parameters. With internal engine development testing almost complete, the first
sample pistons have been released to customers for evaluation. The technology
can be applied to light-duty and heavy-duty diesel pistons.
technology laboratories have developed world-class manufacturing, engine and
engine-like (superimposed TMF-HCMF) bench testing procedures and resources,”
said Morgenstern. “These facilities help us to acquire knowledge more quickly
and in greater depth, leading to faster and more efficient alloy development,”
Source: Federal Mogul