Search found 1148 matches

by Bernd
Thu Aug 27, 2020 12:15 pm
Forum: solidification
Topic: The distribution of solute element
Replies: 6
Views: 338

Re: The distribution of solute element

Hi Yaozu, using "maximum number of new nuclei" is dangerous: If MICRESS happen to choose 5 unfavourable places, it will not check again, and you will not get any seed. I generally advise to use "-1" (unrestricted) here to avoid getting erratic results, and to adjust the number of seeds by using shie...
by Bernd
Wed Aug 26, 2020 7:43 pm
Forum: solidification
Topic: The distribution of solute element
Replies: 6
Views: 338

Re: The distribution of solute element

Dear Yaozu, I am a bit astonished about your description, because if your initial temperature is below solidus temperature (and you don't consider release of latent heat), then you would get a massive transformation without any segregation - perhaps you mean below "liqudus" temperature instead? It i...
by Bernd
Mon Aug 17, 2020 11:43 am
Forum: solidification
Topic: The distribution of solute element
Replies: 6
Views: 338

Re: The distribution of solute element

Hi Shenyz, It is difficult to say what causes the problems without having closer insight into your input file. What I could imagine as reason for the negative Al composition is an insufficient updating rate of the thermodynamic data. This can lead to a too far extrapolation, ending up in the negativ...
by Bernd
Fri Aug 07, 2020 6:24 pm
Forum: solidification
Topic: Temperature coupeling
Replies: 1
Views: 161

Re: Temperature coupeling

Dear g.azizi, In MICRESS it is not possible to couple to concentration and temperature simultaneously. The reason is that the diffusion length for heat and solute are orders of magnitude apart, and solving temperature on the fine grid required for the dendrite with concentration coupling would make ...
by Bernd
Wed Jul 15, 2020 12:54 pm
Forum: solid-solid phase transformations
Topic: Heat Treatment simulation of Ni-alloy
Replies: 33
Views: 8059

Re: Heat Treatment simulation of Ni-alloy

Hi Chamara, In heat treatment simulations automatic time stepping sometimes creates very large phase-field time steps, because diffusion is slow. Slow diffusion in turn leads to low values for the diffusion limited interface mobility if "mob_corr" is used. Normally, this is not a problem because the...
by Bernd
Mon Jul 06, 2020 7:03 pm
Forum: solid-solid phase transformations
Topic: Nucleation on selected grain boundaries
Replies: 6
Views: 1139

Re: Nucleation on selected grain boundaries

Hi Billy, unfortunately, there is still no specific nucleation option in MICRESS which restricts nucleation to certain misorientation values... If you would have said you want to have nucleation only on ferrite-ferrite boundaries with >15° misorientation, this would be what I think is to be expected...
by Bernd
Mon Jun 29, 2020 10:39 am
Forum: post-processing
Topic: how to interpret TabP file
Replies: 1
Views: 309

Re: how to interpret TabP file

Hi jiwonp, Apart from the "CPU Time" which is the sum over the usage of all CPU's, all other columns show wallclock times (using the Fortran DATE_AND_TIME function). We do not distinguish the individual CPU's here because all parallel regions lie completely inside the individual timing blocks. The r...
by Bernd
Wed Jun 10, 2020 3:36 pm
Forum: thermodynamics
Topic: Driving force calculation for NPLE with TQ
Replies: 4
Views: 507

Re: Driving force calculation for NPLE with TQ

Hi Billy, let me answer point by point: 1) I confirm your formulation. For NPLE Mn must also be included, because NPLE implies local equilibrium. 2.) ΔG0 is determined by the parallel tangent construction. Numerically it is calculated in TQ as a dormant equilibrium with one phase with phase fraction...
by Bernd
Tue Jun 09, 2020 11:36 pm
Forum: thermodynamics
Topic: Driving force calculation for NPLE with TQ
Replies: 4
Views: 507

Re: Driving force calculation for NPLE with TQ

Hi Billy, Nice to hear that you are about to bring your thesis to a good end. Indeed, when considering multicomponent systems it is very confusing to use this type of diagram, because it is (without further assumptions) only valid for binary systems. I agree that, as you say in (1), ΔG is calculated...
by Bernd
Tue Jun 02, 2020 3:01 pm
Forum: solidification
Topic: Data for further nucleation
Replies: 64
Views: 12199

Re: Data for further nucleation

Hi Chamara, There is no way assuring a minimum distance of potential nucleation points - it would also be difficult to implement that, because it would not be compatible to freely choosing a radius-seed-density distribution. However, if you set the proper shield distance and a very long shield time,...