special - Alu-web.de
special - Alu-web.de
special - Alu-web.de
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S P E C I A L<br />
A L U M I N I U M I M A U t o M o b I L<br />
a prime requisite for ad<strong>de</strong>d strength<br />
which is further enhanced through<br />
heat treatment. Moreover, the slight<br />
porosity in the cylin<strong>de</strong>r bore zone<br />
opens up the option of coating the<br />
working surface.<br />
Furthermore, Atag has <strong>de</strong>veloped<br />
an innovative inhouse gravity tilt<br />
casting technique inten<strong>de</strong>d for the<br />
<strong>special</strong> operating environment of<br />
high-duty engines, as aluminium in<br />
the form of aluminium castings from<br />
high-gra<strong>de</strong> AlSiMg primary alloys<br />
poses vast challenges regarding thermal<br />
strength. Durability benchmarks<br />
are only addressable with the aid of<br />
an extremely fine microstructure<br />
in the combustion zone of the fire<br />
<strong>de</strong>ck.<br />
One solution to this problem is the<br />
new gravity tilt casting process as it<br />
guarantees a largely low-turbulence<br />
mould-filling at the camshaft end and<br />
a rising layer-by-layer filling of the<br />
mould promoted by the tilting action.<br />
A <strong>de</strong>cisive factor is the highly intense<br />
chilling of the combustion zone at the<br />
fire <strong>de</strong>ck si<strong>de</strong>. The achievable low<br />
<strong>de</strong>ndrite arm spacing reaches benchmark<br />
level.<br />
Another plank in the Atag business<br />
strategy of reducing <strong>de</strong>pen<strong>de</strong>ncy on<br />
engine products is the casting of large<br />
and technologically challenging chassis/suspension<br />
parts in aluminium, a<br />
move that will bolster the company’s<br />
automotive business.<br />
Sectional view of cylin<strong>de</strong>r head cast by gravity tilt casting technique<br />
Brennraumbereich <strong>de</strong>s Feuer<strong>de</strong>cks<br />
erfüllt wer<strong>de</strong>n.<br />
Das neue Schwerkraft-Kippgießverfahren<br />
trägt zur Problemlösung<br />
bei, in<strong>de</strong>m es für eine weitgehend<br />
turbulenzarme Formfüllung auf <strong>de</strong>r<br />
Nockenwellenseite und eine vom<br />
Kippvorgang begünstigte, schichtend<br />
steigen<strong>de</strong> Füllung <strong>de</strong>r Kokille sorgt.<br />
Von entschei<strong>de</strong>n<strong>de</strong>r Be<strong>de</strong>utung ist<br />
dabei eine höchst intensive Abschreckung<br />
<strong>de</strong>s Brennraumbereichs auf <strong>de</strong>r<br />
Feuer<strong>de</strong>ckseite. Hierbei erreicht <strong>de</strong>r<br />
A U t o M o t I v E<br />
Mit ihrem modularen Druckgusskonzept steigert Atag die Festigkeit downgesizter<br />
Zylin<strong>de</strong>rkurbelgehäuse<br />
Atag has <strong>de</strong>veloped the modular die-casting concept for enhancing the strength of downsized<br />
engine blocks<br />
erzielbare, geringe Dendritenarmabstand<br />
Atag zufolge „Benchmarkniveau“.<br />
Zukünftig soll ein gänzlich neues<br />
Produktfeld das Atag-Geschäft unabhängiger<br />
vom Antriebskonzept machen.<br />
Dazu gehört beispielsweise das<br />
Gießen großer und komplexer, mithin<br />
gießtechnisch herausfor<strong>de</strong>rn<strong>de</strong>r<br />
Fahrwerksteile aus <strong>Alu</strong>minium. Mit<br />
dieser Neuausrichtung wird das Unternehmen<br />
sein Automotive-Geschäft<br />
weiter stärken.<br />
■ ■<br />
25 ALUMINIUM · 9/2009<br />
ALUMINIUM · 9/2009 25