KTH Solute Drag

ripening phenomena, dislocations, grainboundary topology
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ning
Posts: 13
Joined: Wed Jul 29, 2009 10:06 pm

KTH Solute Drag

Post by ning » Thu Aug 20, 2009 10:23 pm

In mobility data file, what are the physical meaning and corresponding dimension of each column?
Thanks.
Ning

Bernd
Posts: 1074
Joined: Mon Jun 23, 2008 9:29 pm

Re: KTH Solute Drag

Post by Bernd » Fri Aug 21, 2009 1:40 pm

Dear ning,

the sd_kth option in the mobility input is a special solution for KTH in Stockholm which makes no sense for other users (see also here). You can use instead a constant, temperature dependent or driving force dependent mobility. In the latter two cases, the input format is an ASCII file with the first column being temperature [K] or driving force [J/cm3], respectively. The second column is the mobility [cm4/(Js)] which is linearily interpolated according to the value in the first column.

Bernd

ning
Posts: 13
Joined: Wed Jul 29, 2009 10:06 pm

Re: KTH Solute Drag

Post by ning » Fri Aug 21, 2009 2:52 pm

Dear Bernd:
Got it. Then how the driving force is actually calculated in the program? I tried to output it by enabling .driv but it didn't work.
Thanks.
Ning
Bernd wrote:Dear ning,

the sd_kth option in the mobility input is a special solution for KTH in Stockholm which makes no sense for other users (see also here). You can use instead a constant, temperature dependent or driving force dependent mobility. In the latter two cases, the input format is an ASCII file with the first column being temperature [K] or driving force [J/cm3], respectively. The second column is the mobility [cm4/(Js)] which is linearily interpolated according to the value in the first column.

Bernd

Bernd
Posts: 1074
Joined: Mon Jun 23, 2008 9:29 pm

Re: KTH Solute Drag

Post by Bernd » Fri Aug 21, 2009 8:28 pm

Dear ning,

The .driv output displays only the chemical part of the driving force. This may exist for interactions between different phases or for recrystallisation, but it does not include curvature contributions. Thus it depends on the example whether the .driv output will show anything or not.
The chemical driving force is calculated dependent from the local composition and temperature according to the quasi-equilibrium approach (see PHYSICAL REVIEW E 73, 066122 (2006) "Multiphase-field approach for multicomponent alloys with extrapolation scheme for numerical application" J. Eiken, B.Boettger, and I. Steinbach). For recrystallisation, the driving force is equal to the difference in the stored energies of both grains.
For simulation of alloys it is recommended to average the driving force across the interface like described here. The interpretation of the .driv output is described here.

Bernd

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