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: models: metallic cao-al2o3-sio2 eutectic

updated thu 5 jun 03


iandol on tue 3 jun 03

Dear Louis Katz,=20

You are so right about Models. They are great tools to aid thinking.=20

You are also right that current concepts relating the models we make for =
the materials we use which we term "Fluxing" is seriously flawed. We get =
a better model if we change to thinking in terms of things which will =
act as Solvents and things which will Dissolve then incorporate in the =
change these additions make to Physical Qualities such as Surface =
Tension and Fluidity or Viscosity.

Those lines on Ternary Phase Diagrams which define the Liquidus Surface =
are Isotherms. I made this point in the Article in Ceramics Technical a =
couple of issues ago.

One point that people may miss when they use Phase Equilibrium diagrams =
is that many of them fail to show the presence of Solid Solutions, where =
a natural ingredient such as Kaolin has a very small quantities of =
another elements incorporated into the lattice structure of its =
crystals, insufficient to cause the creation of a new species of =
mineral. These inclusions in a Solid Solution can have a significant =
effect in lowering the Solidus Temperature and results in a seemingly =
incongruous low melting point. It is a fact which cannot be ignored in =
our Model. But there is no evidence that people ignorant of this fact =
would claim it to be the action of a Eutectic.=20

No my Friend, you do not ramble. You are Flint on which my imagination =
Best regards,