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Development of hypereutectic aluminium silicon alloys for automotive components

Objective



Aim of the project is the development of hypereutectic
aluminium silicon alloys able to be processed by
different technologies as: squeeze casting, lost foem
and thixoforming, in order to produce, in a cost
effective way, automotive components such as branking
rotor drums, engine block, gear forks.
The use of light alloys in the transport industry is
becoming a stringent need; weight saving is one of the
most important targets in new vehicles design which must
comply with more and more restrictive limitations
concerning fuel consumption and exhaust emission.
Hypereutectic Aluminium Silicon alloys have good wear
resistance combined with high modulus (E), high
conductivity and good thermal stability (low CTE); that
makes them attractive for the automotive industry in
particular for many applications where the hypoeutectic
aluminium alloys are not employable in replacing the
traditional materials (cast iron, steel)/ Some
technological limits are anyway present concerning these
alloys: high liquidus temperature, wide freezing range,
suitability only for casting processes which permit high
solidification rate, not uniform distribution of Si
crystals, necessity to perform electrochemical etching
for improving the wear properties. These problems limit
at the present time their market widespread.
The strategic objectives of this project for each
component are:
*ENGINE BLOCKS: the good mechanical properties of
hypereutectic aluminium alloys, in particular wear
resistance, will permit to realise a cast in liners
cylinder block. The substitution of today engine blocks,
cast iron made or hypoeutectic aluminium alloys made with
cast iron inserted cylinder, with hypereutectic alloys.
engines produced by lost foam will allow a weight saving
of about 30 40% keeping the cost at the same level and
increasing time to mrket and flexibility.
*BRAKE ROTORS: at the present time cast iron made;
high wear resistance, good thermal stability, high E
modulus, high conductivity and low expansion coefficient
make the hypereutectic alloys the best candidate among
the light alloys in replacing the traditional material.
The expected weight saving should be of about 30 50%
keeping the cost at the same level and improving the
total cast quality.
*GEAR FORKS: at the present time brass made; the
hypereutectic alloys can guarrantee high stiffness and
wear performance especially at high temperatures. The
expected weight saving should be of about 40 50% with
cost reduction of the order of 15 20%.
Moreover, significant advantages on fuel consumption
saving and on the cars' active safety and comfort as well
as on the environmental aspect (by promoting the use of
fully recyclable alloys) are to be expected.
Finally the new hypereutectic alloys could be employed on
many components, also in other industrial sectors than
automotive where weight saving is considered an important
goal.
The expected market of these new alloys, referring to the
automotive components described, has been evaluated of
about 140 MECUs.
Specifically innovative achievements will be:
*Specification for a new generation of hypereutectic
alloys
*The development of a model based on the relationship
between raw materials, processing techniques and final
properties.
*Validated GUIDELINES and DESIGN CODES (for lost foam
process) for the production of sound automotive
components.
The workprogramme consists of 5 major tasks with a
progressive change from a more scientifically view of the
problem to the industrial view of the utilisation of the
alloys. A relatively large consortium is necessary to
bring together complementary players from all parts of
the supply chain supported by research organizations with
particular experience and facilities.

Coordinator

ISRIM Scarl - Istituto Superiore di Ricerca e Formazione sui Materiali Speciali per le Tecnologie Avanzate
Address
Località Pentima Bassa 21
05100 Terni
Italy

Participants (10)

Allied Signal Bremsblag GmbH
Germany
Address

21504 Glinde
Aluminium Pechiney
France
Address
Centr'alp
38340 Voreppe
Bosch Systèmes de Freinage SAS
France
Address
126,Rue De Stalingrad 126
93700 Drancy
CENTRO DE ESTUDIOS E INVESTIGACIONES TECNICAS DE GUIPUZKOA
Spain
Address
15,Paseo De Manuel De Lardizabal 15
20009 San Sebastian
CENTRO RICERCHE FIAT S.C.P.A
Italy
Address
50,Strada Torino, 50
10043 Orbassano
Fagor Ederlan S.Coop. Ltda
Spain
Address

20540 Escoriaza
Hydro Aluminium AS
Ireland
Address
264,Kindrum, Cashel
1321 Letterkenny
RISOE NATIONAL LABORATORY
Denmark
Address
Frederiksborgvej 399
Roskilde
STAMPAL SPA
Italy
Address
Via Lombardia 6
10071 Borgaro Torinese
UNIVERSITY OF SHEFFIELD
United Kingdom
Address
Mappin Street Sir Robert Hadfield Building
S1 3JD Sheffield