Search found 1505 matches

by Bernd
Thu Mar 21, 2024 6:19 pm
Forum: tips and tricks
Topic: Temperature - profiles_from_file tool
Replies: 1
Views: 39

Re: Temperature - profiles_from_file tool

Hi Mauro, If you mean with "200 data points" that you have 200 time steps with corresponding 200 temperature profiles, then you are right, and unfortunately there is currently no other way how to input that into the driving file. Do you have a proposal how we could simplify this procedure? If we wou...
by Bernd
Thu Mar 21, 2024 4:00 pm
Forum: solidification
Topic: Predicting of PDAS
Replies: 2
Views: 32

Re: Predicting of PDAS

Hi Sean, In principle, the unit cell approach with KGT-calibrated interface mobility is a good basis for investigation of the PDAS. However, your conclusion, that the invariance of the tip temperature with changing PDAS (i.e. domain size) would indicate the stable PDAS value, is wrong. The tip under...
by Bernd
Tue Feb 13, 2024 2:00 pm
Forum: solidification
Topic: 3D Simulation of direct solidification
Replies: 5
Views: 302

Re: 3D Simulation of direct solidification

Hi Sean, it seems you applied the factor of 16 also to the kinetic anisotropy coefficient, which is not correct: It should be only the static one! Thus, you are missing kinetic anisotropy. This, although physically viable, is not useful with phase-field simulations which are not extremely fine resol...
by Bernd
Tue Feb 06, 2024 5:00 pm
Forum: solidification
Topic: 3D Simulation of direct solidification
Replies: 5
Views: 302

Re: 3D Simulation of direct solidification

Dear Sean, Nice to hear from you. Your simulation results look very nice! Let me try to start with the first question about the anisotropy coefficients. Unfortunately it is difficult to get physical values, and there is no general strategy what to do then. But on top of that problem, I think there i...
by Bernd
Mon Feb 05, 2024 2:52 pm
Forum: solidification
Topic: using appropriate phase to mimic substrate layer in LPBF process
Replies: 1
Views: 100

Re: using appropriate phase to mimic substrate layer in LPBF process

Dear Hanyu, Welcome to the MICRESS Forum! You describe a case where 2 phases can equally well grow as primary phase and thus compete with each other. This means, the question which one will prevail or overgrow the other strongly depends on the nucleation conditions for each phase. And the opportunit...
by Bernd
Tue Dec 26, 2023 3:40 am
Forum: solid-solid phase transformations
Topic: Broad interfaces
Replies: 3
Views: 56451

Re: Broad interfaces

Dear Roscoe, Possibly, the problem is due to multi-binary demixing, as indicated by the error messages. In that case, the solution would be using diagonal redistribution (keyword "diagonal" in section phase diagram input for version 6.4) which anyway is recommended for non-dilute alloys. However, it...
by Bernd
Fri Dec 08, 2023 2:08 pm
Forum: solidification
Topic: Dendritic growth under high cooling rates
Replies: 7
Views: 94297

Re: Dendritic growth under high cooling rates

Dear Peter,

No, you misunderstood me - you just need to replace the wrong input "avg 0.5" by the correct value of the interface energy!

Bernd
by Bernd
Fri Dec 08, 2023 1:14 pm
Forum: solidification
Topic: Dendritic growth under high cooling rates
Replies: 7
Views: 94297

Re: Dendritic growth under high cooling rates

Dear PeGr, The error message you get from MICRESS looks a bit strange, because input errors in the 1/1-, 2/2-, and 3/3-phase interactions are not correctly recognized. Instead of specifying a value for the interface energy, you input "avg 0.5". This is obviously wrong, but not directly recognized as...
by Bernd
Wed Dec 06, 2023 2:01 pm
Forum: solid-solid phase transformations
Topic: Broad interfaces
Replies: 3
Views: 56451

Re: Broad interfaces

Dear Roscoe, What you experience is a broadening (spreading) of the interface due to numerical problems. There can be many reasons for interfaces to get unstable. The most typical are: - too low grid resolution - too high interface mobility (if no mobility correction is used) - missing diffusion - t...
by Bernd
Tue Dec 05, 2023 10:47 pm
Forum: solidification
Topic: Grain size versus cooling rate ?
Replies: 6
Views: 94659

Re: Grain size versus cooling rate ?

Dear Stéphane, That sounds reasonable. The basic idea of the seed density model does neither have shielding nor nucleation rates, so, in principle, having infinitely small checking intervals and a shield distance of 0 (or shield time of 0) is perfect. We have left the shield effect available just fo...