If you took two identical aluminum alloy castings and then had one cold
worked (rolled, ect.) the cold worked sample would be much stronger and less
ductile.  It would also be less thermally conductive, but not by much, due
to the huge increase in dislocations which are simply microstructure
defects.

<html><DIV>'85 Silver Sunroof&nbsp;&nbsp;&nbsp;O===O&nbsp;&nbsp; <BR>
'81 Westy Beater&nbsp;&nbsp;&nbsp;O===O&nbsp;&nbsp; <BR>
'91 GTi 2.0 8v&nbsp;&nbsp; Oo=oO&nbsp;&nbsp; <BR>'76 BMW 2002&nbsp;&nbsp;
O=00=O&nbsp;&nbsp; </DIV>
<DIV>&nbsp;</DIV>
<DIV>&nbsp;</DIV>
<DIV>&nbsp;</DIV></html>

&gt;From: John Rodgers &lt;jh_rodgers@BELLSOUTH.NET&gt;
&gt;Reply-To: John Rodgers &lt;jh_rodgers@BELLSOUTH.NET&gt;
&gt;To: vanagon@GERRY.VANAGON.COM
&gt;Subject: Curious Question (NVC)
&gt;Date: Tue, 29 Jun 2004 14:43:17 -0500
&gt;
&gt;I'm not an engineer, but have a question.
&gt;
&gt;Cast aluminum has a granular crystal quality in it's structure.
&gt;Milled
&gt;Aluminum (hammered, rolled) does not.
&gt;
&gt;Of two identical parts, one a machnined aluminum casting, and the
&gt;other
&gt;machined in milled aluminum, which would most likely have the best
&gt;1)
&gt;strength 2) heat transfer properties.
&gt;
&gt;Inquiring minds would like to know!
&gt;
&gt;Anybody??
&gt;
&gt;Thanks,
&gt;
&gt;John Rodgers
&gt;88 GL Driver

_________________________________________________________________
Make the most of your family vacation with tips from the MSN Family Travel
Guide! http://dollar.msn.com