MICRESS Forum

Hi Ben, This is right. It must be like that, otherwise the mass balance is violated! It is also the reason why we are mostly using the "small grain" model for nucleation: If only a small fraction in one cell is used as initial seed, composition balance can be fulfilled without starting from a comple...

Dear nokkikku, the global keyword "averaging / no_averaging" (Flags and Settings) was removed since version 5.504 because it had lost its function. "averaging" specifies that averaging of the driving force across the interface should be performed in case of concentration coupling. But there is anoth...

Dear shoney, Welcome to the MICRESS forum! The initial conditions for a simulation depend a lot on the simulation setup and the problem you want to treat. I you say isothermal, then it sounds like a free growing equiaxed dendrite, but it could also be a free growing columnar dendrite front. In gener...

Hi zhubq, no, I do not agree at all! Local curvature gives and additional contribution to the total driving force. If the interface is in local equilibrium (total driving force is 0), then the chemical driving force must compensate for thát, and that is only possible via a change in composition. In ...

Dear Nico, for me it is not so clear what to expect during solidification. You have to take into account that solidification microstructures are not at equilibrium, and, therefore, the solidification path does not correspond to what you see in the phase diagram! What do you mean with that you did no...

Hi zhubq, for exactly this reason, we are using double precision (R8) in MICRESS for the diffusion solver, even if the memory usage is higher! We found the strongest problems when using the 1d extension of the concentration field with long-range diffusion profiles. Of course, one can try to reduce p...

Dear Nico, this sounds as if the phase diagram you have could also be rather schematic than quantitatively correct... But at least simulation seems to give something which qualitatively is comparable to experimental evidence, the phase sequence is correct, isn't it? Of course it would be nice to per...

Dear NicoSim You cannot change the order of appearance of the phases by numerical measures, because it is a physical property of the system (as long as we trust in the database and do not change composition). From the phase diagram to which you send us the link, it seems that fcc and bcc should appe...

Dear NicoSim, if it is like you say, the system seems to be quite complex, or the database is not not valid for the composition of your alloy. Which database are you using? Anyway, you should define the stoichiometric components such that no "demixing" occurs, in worst case you have to set all compo...

Dear NicoSim, from what I see in the pasted log-file, in phase 2, component 2 and 3 should be set to stoichiometric instead of 1 and 2 (for phase 1, setting of 1 and 2 is perfect). Maybe, this makes the problems, please check and tell me! Finding the correct stoichiometric conditions is one of the f...