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Inaccurate edit
This article suffers from inaccuracy in many areas. It seems to be written more on information handed down from shop-floor conversations and automotive hearsay than on materials science. It needs review by a materials scientist or engineer. 66.185.72.80 (talk) 04:36, 24 September 2009 (UTC)
- I'm the one who flagged the article and left the message above. I rewrote the first two paragraphs for accuracy. Phasmatisnox (talk) 04:56, 24 September 2009 (UTC)
2618 edit
The 2618 paragraph is vague and confusing. Why are they thicker? Wouldn't they be more susceptible to heart? --Gbleem 19:15, 12 January 2007 (UTC)
Unalloyed edit
Doesn't the alloying problem (technically) only apply in a gravity field? (OK, not many piston manufacturers in LEO ;D) Trekphiler 16:34, 12 August 2007 (UTC)
There are clealry some errors in this article.
Eutectic mixtures do not from single homogenous phases when they freeze.
Their structures are usually lammellar and comprise of two phases (commonly referred to as as alpha and beta)
The Eutectic mixture has two other interesting properties.
The first is that it is the lowest melting point mixture of the specific alloy series. (60/40 Brass is a good example)
This means that a piston cast from this material has the lowest cost in terms of theraml energy.
The Eutectic Point is also athermal. When the alloy freezes it does not have a freezing range but solidifies instantly at a very specific temperature.
This means die castings can quickly be removed from a mould and reltively high production rates obtained.
So Eutectic pistons have relatively low expansion, are relatively cheap to cast and can be produced quickly.
2618 has a much higher strength at temperature than 4032 for example and despite the increased expansion is more stable as it it does not suffer from the diffusion of Silicon which can cause premature failure.
2618 also has a freezing range f about 100 degrees so the cast blanks used in its production stay longer in the mould. —Preceding unsigned comment added by FennLane (talk • contribs) 19:50, 22 December 2009 (UTC)