Re: liquid mixing

What's the interest in mixing mix two different alloys as partial liquid? Use the cores and chemical inhomogenities as tracers for solidification. Initial reaction is that when you increased the size of the feeders you doubled the mass flow and overloaded the heat extraction of the feed/reactor. Do the temperatures at the various points in the process and a quick heat capacity balance make sense? Up scaling has always been a problem with solidification (remembering some reocasting work from the mid 70's). At +10C all you need to do is pour the material into a container somewhat below the liquidus of the alloy to get a nondendritic structure. Various mode of agitation during subsequent solidification can produce some interesting macrograin and segregation patterns in the nondendritic matrix.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
/DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV><FONT face="Bookman Old Style" size=2>----What's the interest in mixing two different alloys as partial liquid?&nbsp; Use the cores and chemical inhomogenities as&nbsp;tracers for solidification.&nbsp;&nbsp;</FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>What do you mean by partial liquid?&nbsp;&nbsp; Trying to trace soslidification patterns is something we are working on as well, especially in the simulation department.</FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>----Initial reaction is that when you increased the size of the feeders you doubled the mass flow and overloaded the heat extraction of the feed/reactor.&nbsp; </FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>Makes sense.&nbsp;&nbsp; Which brings to mind that a major factor as well is velocity of the melts as they barrellass down the tubes to the reactor.&nbsp;&nbsp; </FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>----Do the temperatures at the various points in the process and a quick heat capacity balance make sense?&nbsp; </FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>Doing heat transfer calculations in this situation is very tricky, because it's such a transient, dynamic problem since flow is combined with heat extraction.&nbsp; But to quantify what's going on...again, simulation fodder.</FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>----Up scaling has always been a problem with solidification (remembering some rheocasting work from the mid 70's).&nbsp; At +10C all you need to do is pour the material into a container somewhat ----below the liquidus of the alloy to get a nondendritic structure.&nbsp; </FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>Right, liquidus casting...the mechanisms of which are joined to the hip to those controlling this process.&nbsp; It all comes back to Ohno's wall theory, that's one of the major controlling factors, but at the same time one aim of this process is a large working temperature range.&nbsp; </FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>----Various mode of agitation during subsequent solidification can produce some interesting macrograin and segregation patterns in the nondendritic matrix.&nbsp; </FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>Could you elaborate on that?&nbsp; Are you implying that too much agitation at a certain point causes instabilities in the SSM structure?&nbsp; You are referring to segregation of the subsequent eutectic matrix, correct?</FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face="Bookman Old Style" size=2>Many SSM processes&nbsp;use the terminology of&nbsp;"shear," which&nbsp;can be&nbsp;measurable, when talking about liquid agitation.&nbsp; Here we are thinking more along the lines of chaotic turbulence, and forced convection, which is difficult to quantify, therefore may be a bitch to control in "real life".&nbsp;&nbsp;&nbsp;Therein lies the trickiness to our dilemma.</FONT></DIV> <DIV><FONT face="Bookman Old Style" size=2></FONT>&nbsp;</DIV> <DIV><FONT face=Verdana size=2></FONT>&nbsp;</DIV></BLOCKQUOTE></BODY></HTML>
------=
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.