In my email inbox, anyone can attend.

mollwollfumble said:

In my email inbox, anyone can attend.

Got any links on phase-field so I can find out why I should find out about phase-field?

The Rev Dodgson said:

mollwollfumble said:

In my email inbox, anyone can attend.

Got any links on phase-field so I can find out why I should find out about phase-field?

:-)

Thank you for responding to my lure. I didn’t know what phase-field was either.

He’s talking about solidification of metals. You know how alloys can exist in many phases in a phase diagram. Phase transitions can range from dendritic growth in an undercooled liquid to preferential growth on crystal faces to solid-solid transitions.

“We define the phase field p_i to be the metallic fraction of phase i.” The sum over all phases is 1. The transition from one phase to the other is governed by what he calls the ‘free energy’, I’d call it the ‘surface energy’. The potential energy comes from the deviation from thermodynamic equilibrium.

We end up with equations of motion for phase boundaries. These equations come from minimisation of the local free energy of the system.

This is the sort of stuff that I call “obvious in retrospect”. Practical applications include selecting temperatures and concentration to generate desired metallic microstructures. I’m not sure if the theory is advanced enough to be able to predict the shape of a snowflake from the variations in temperature and humidity during its formation, but it certainly makes a valiant attempt.

In my work I often had to calculate the rate of evaporation, and occasionally the rate of corrosion, and I’d be interested how close this theory comes to being able to predict both.

Feel free to add any other scientific junk mail from your inbox to this thread.

mollwollfumble said:

The Rev Dodgson said:

mollwollfumble said:

In my email inbox, anyone can attend.

Got any links on phase-field so I can find out why I should find out about phase-field?

:-)

Thank you for responding to my lure. I didn’t know what phase-field was either.

He’s talking about solidification of metals. You know how alloys can exist in many phases in a phase diagram. Phase transitions can range from dendritic growth in an undercooled liquid to preferential growth on crystal faces to solid-solid transitions.

“We define the phase field p_i to be the metallic fraction of phase i.” The sum over all phases is 1. The transition from one phase to the other is governed by what he calls the ‘free energy’, I’d call it the ‘surface energy’. The potential energy comes from the deviation from thermodynamic equilibrium.

We end up with equations of motion for phase boundaries. These equations come from minimisation of the local free energy of the system.

This is the sort of stuff that I call “obvious in retrospect”. Practical applications include selecting temperatures and concentration to generate desired metallic microstructures. I’m not sure if the theory is advanced enough to be able to predict the shape of a snowflake from the variations in temperature and humidity during its formation, but it certainly makes a valiant attempt.

In my work I often had to calculate the rate of evaporation, and occasionally the rate of corrosion, and I’d be interested how close this theory comes to being able to predict both.

Feel free to add any other scientific junk mail from your inbox to this thread.

Thanks for that.

I might give that one a miss, good thread though. I’ll go and have a look through my e-mails (when I have time).