Maximum nucleation temperature

dendritic solidification, eutectics, peritectics,....
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Moritz
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Maximum nucleation temperature

Post by Moritz » Fri Feb 11, 2022 12:26 pm

Hello everyone,

recently, I was a little bit confused about the correct setting of the maximum solidification temperature.

I want to simulate an alloy which is made up of essentially iron and chromium. TiN (titanium nitrade) particles are used to refine the microstrucure.

Titanium and nitrogen are not included into the simulation, only the effects of these particles are represented for example with the Zener pinning effect, seeds for nucleation and so on.

My question is: Is it correct to set the maximum nucleation temperature to the liquidus temperature of the alloy minus the necessary undercooling temperature to have grains forming at the seeds?

My concern is, that I don't want to set a lower solidification temperature, when MICRESS already considers necessary undercooling, for example.

As always, I am looking forward for your replies!

Best regards,

Moritz

Bernd
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Joined: Mon Jun 23, 2008 9:29 pm

Re: Maximum nucleation temperature

Post by Bernd » Fri Feb 11, 2022 3:43 pm

Dear Moritz,

The temperature range for nucleation is considering the local temperature at the place where nucleation is to be checked. If temperature is outside this range, nucleation is not checked at that point.

Please note that the nucleation temperature range should not be used to implement a certain nucleation undercooling (this should be done using the critical undercooling for nucleation with or without curvature contribution). The purpose for which the temperature range for nucleation should be used is only performance (because checking at irrelevant temperatures can cost a lot of simulation time) and preventing thermodynamic problems in spinodal systems (not checking above critical temperature!) or in other thermodynamically weird situations. Perhaps, one may further misuse the option for temporarily switching off a certain seed type for testing purposes...

Bernd

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