Not a valid question. Who knows how hot a melt will get? That
obviously depends on its specific environment.
What is known easily is the freezing point of iron or a phase diagram
of allys as well including nickel and carbon whioch gets complicated.
The formation of the Widmanstatten figures happens in the solid phase,
not upon the freezing; this probably occurs mostly around the annealing
temperature of the meteorite alloy which will be between 600 C (about
to 20% nickel) to 912 C (no nickel). In chemistry there are no
absolutes, just temperature dependent equilibrium constants, so
probably the pattern can form insignificantly as low as 200 C. So,
depending on pressure (depth) gravitational and fission sources of
heat, plus if the Sun happens to be close, the core will solidify at
2200 to 2500 C in some conditions.... and cool and be a kind of labile
solid, and cool and cool and start organizing the lattice structure
with separating alpha (low nickel body centered) and gamma (high nickel
8% or so denser face centered) bands of kamacite and taenite,
respectively...
-----Original Message-----
From: pshugar <[email protected]>
To: The List <[email protected]>
Sent: Mon, Dec 26, 2011 5:37 pm
Subject: [meteorite-list] A good question
we know that iron asteroids come from the cores of the
differentiated bodies.
The Whittmanstraden pattern is the slow cooling over
exceedingly long periods of time.
The question--what is the temp of the molten iron
before it starts to cool.
Pete Shugar
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