Error when linearisation!

[CharMIC]

Hej,

I am simulating a Nickel Alloy solidification with LAVES phase precipitation. After LAVES phase has been precipitated, I get linearisation error when the temperature of the domain continues to drop to the room temperature. I started to get the error when the domain temperature reaches to 1020K. After that simulation continues with increasing number of error massages and finally it crash.

I have used the "interaction" keyword under Phase diagram data. But still I get his error. Is it related to extreme slopes between phase1(gamma)/phase2(Laves)? or something else?


# The linearisation parameters of the phases FCC_L12/C14_LAVES are:
# -----------------------------------------------------------------
1458.5692 ! T0 [K]
214.12248 ! dG [J/cm**3]
0.46606137 ! dSf+ [J/cm**3K]
-0.28205241 ! dSf- [J/cm**3K]
2348.6440 ! dH [J/cm3]
0.59792283218921 ! c0(AL)/FCC_L12
0.10247914576806 ! c0(AL)/C14_LAVES
19.741910925912 ! c0(CR)/FCC_L12
14.998959328989 ! c0(CR)/C14_LAVES
19.534087093182 ! c0(FE)/FCC_L12
19.351556234489 ! c0(FE)/C14_LAVES
2.2987221612929 ! c0(MO)/FCC_L12
0.54466112441877 ! c0(MO)/C14_LAVES
6.1067820250772 ! c0(NB)/FCC_L12
37.366557880526 ! c0(NB)/C14_LAVES
0.63105639674078 ! c0(TI)/FCC_L12
0.16318358850256 ! c0(TI)/C14_LAVES
170.91765 ! m(AL)/FCC_L12
662.50101 ! m(AL)/C14_LAVES
89.928248 ! m(CR)/FCC_L12
-57.720639 ! m(CR)/C14_LAVES
66.989709 ! m(FE)/FCC_L12
-25.229648 ! m(FE)/C14_LAVES
23.039178 ! m(MO)/FCC_L12
15.469622 ! m(MO)/C14_LAVES
215.44844 ! m(NB)/FCC_L12
-122.82913 ! m(NB)/C14_LAVES
147.58493 ! m(TI)/FCC_L12
13.276200 ! m(TI)/C14_LAVES
-2.00048963E-03 ! dcdT(AL)/FCC_L12
2.10477585E-04 ! dcdT(AL)/C14_LAVES
4.54025849E-03 ! dcdT(CR)/FCC_L12
2.47541312E-03 ! dcdT(CR)/C14_LAVES
8.36899138E-03 ! dcdT(FE)/FCC_L12
-7.27836073E-03 ! dcdT(FE)/C14_LAVES
7.50114110E-05 ! dcdT(MO)/FCC_L12
4.18229729E-04 ! dcdT(MO)/C14_LAVES
5.86545578E-03 ! dcdT(NB)/FCC_L12
-1.65279599E-02 ! dcdT(NB)/C14_LAVES
-4.76598540E-04 ! dcdT(TI)/FCC_L12
-2.95609719E-05 ! dcdT(TI)/C14_LAVES


#Error massages-----------------------------------------------------------------------------------------------------------

Updating of diffusion data from database...
complete relinearisation!
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
trying hard phases 1 2 level: 3 zp= 4818 error= 18
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
trying hard phases 1 2 level: 4 zp= 213050 error= 18
trying harder! Error = 18
Updating of diffusion data from database...
complete relinearisation!
Updating of diffusion data from database...
complete relinearisation!
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
trying hard phases 1 2 level: 4 zp= 185777 error= 18
trying harder! Error = 18
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
trying even harder! Error 18

--> Force automatic start values
Thermo-Calc error 1611 MICRESS error 18 phases 1/ 2
# Error number 18 in Interface 1/ 280
# time: 0.963840000000386 s
# Serious error in linearisation!

Intermediate output for t = 1.0000 s
CPU-time: 820981 s
.
.
.
.
.
.

Intermediate output for t = 4.0000 s
CPU-time: 14487 s

Temperature at the bottom = 605.49 K
Temperature gradient = 0.00000 K/cm
Updating of diffusion data from database...
complete relinearisation!
trying hard phases 2 1 level: 3 zp= 1212 error= 1
trying hard phases 1 2 level: 8 zp= 63186 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 167665 error= 1
trying hard phases 1 2 level: 3 zp= 86203 error= 1
trying hard phases 1 2 level: 4 zp= 136713 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 88718 error= 1
trying hard phases 1 2 level: 4 zp= 187780 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 6 zp= 184965 error= 1
trying hard phases 1 2 level: 8 zp= 16244 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 9 zp= 164845 error= 1
trying harder! Error = 1
trying hard phases 2 1 level: 4 zp= 4979 error= 1
trying hard phases 1 2 level: 6 zp= 73013 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 3 zp= 126100 error= 104
trying hard phases 1 2 level: 4 zp= 211249 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 71809 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 123692 error= 1
trying hard phases 1 2 level: 4 zp= 173914 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 68193 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 142353 error= 1
trying hard phases 1 2 level: 7 zp= 123688 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 3 zp= 114446 error= 1
trying hard phases 1 2 level: 4 zp= 217269 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 37108 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 199416 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 193009 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 154394 error= 1
trying hard phases 1 2 level: 5 zp= 206038 error= 1
trying hard phases 1 2 level: 4 zp= 8688 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 103604 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 3 zp= 190991 error= 1
trying hard phases 1 2 level: 3 zp= 45529 error= 1
trying hard phases 1 2 level: 4 zp= 189394 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 177544 error= 3
trying hard phases 1 2 level: 6 zp= 186183 error= 1
trying harder! Error = 1
Thermo-Calc error 1611 MICRESS error 17 phases 1/ 2
trying even harder! Error 17

--> Force automatic start values
trying hard phases 1 2 level: 4 zp= 87761 error= 1
trying harder! Error = 1
Updating of diffusion data from database...
complete relinearisation!
trying hard phases 2 1 level: 4 zp= 1212 error= 1
trying hard phases 1 2 level: 7 zp= 63186 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 4 zp= 167665 error= 1
trying hard phases 1 2 level: 3 zp= 86203 error= 1
trying hard phases 1 2 level: 4 zp= 88718 error= 1
trying harder! Error = 1
trying hard phases 1 2 level: 5 zp= 187780 error= 3
trying harder! Error = 3
trying hard phases 1 2 level: 5 zp= 184965 error= 1
trying hard phases 1 2 level: 6 zp= 16244 error= 1
trying harder! Error = 1
trying hard phases 1 2 level:10 zp= 164845 error= 1
trying harder! Error = 1
trying hard phases 2 1 level: 5 zp= 4979 error= 1
trying hard phases 1 2 level: 6 zp= 73013 error= 1
trying harder! Error = 1
forrtl: error (73): floating divide by zero
Image PC Routine Line Source
libtq-linux-x86_6 00007F4ED7CCD499 Unknown Unknown Unknown
libtq-linux-x86_6 00007F4ED7CCBD6E Unknown Unknown Unknown
libtq-linux-x86_6 00007F4ED7C93EAF Unknown Unknown Unknown
libtq-linux-x86_6 00007F4ED7C40D8F Unknown Unknown Unknown
libtq-linux-x86_6 00007F4ED7C458C9 Unknown Unknown Unknown
libpthread.so.0 00007F4ED7196100 Unknown Unknown Unknown
libtq-linux-x86_6 00007F4ED797DC6D qinvr2_ 5479 roptim.F
libtq-linux-x86_6 00007F4ED78193DE qinvg2_ 2884 eq_cal.F
libtq-linux-x86_6 00007F4ED7818777 qphinv_ 1277 eq_cal.F
libtq-linux-x86_6 00007F4ED7814D47 qthiss_ 669 eq_cal.F
libtq-linux-x86_6 00007F4ED7813AD2 qequil_ 153 eq_cal.F
libtq-linux-x86_6 00007F4ED76A2EFB tqce_ 2043 tqface.F
MICRESS_par_TQ 0000000000C4ABBF Unknown Unknown Unknown
MICRESS_par_TQ 0000000000C364F9 Unknown Unknown Unknown
MICRESS_par_TQ 0000000000C27D3D Unknown Unknown Unknown
MICRESS_par_TQ 0000000000C72EAD Unknown Unknown Unknown
MICRESS_par_TQ 0000000000AFC6B8 Unknown Unknown Unknown
MICRESS_par_TQ 000000000084CCC2 Unknown Unknown Unknown
MICRESS_par_TQ 000000000040C0B6 Unknown Unknown Unknown
libc.so.6 00007F4ED6AD8B15 Unknown Unknown Unknown
MICRESS_par_TQ 000000000040BFA9 Unknown Unknown Unknown

BR
Chamara

[Bernd]

Dear Chamara,

There are many possible reasons for that. The first I would have a look on is a possible miscibility gap occurring for the Laves phase. To check that, there are different options:

1.) Check the phase composition output for the Laves phase (*.c*pha2) for which you probably need to activate output - by the way, I always write phase concentration outputs for all phases for debugging purposes ("out_conc_phase 0 | 1 | 2 ..."). If you notice an abrupt change of one or several components somewhere at the interface, it is a good sign for a switch to another composition set because you are close to a miscibility gap.

2.) Check the .TabLin output over time. There, you can also notice any abrupt composition change for the reference compositions in Laves.

3.) A Thermo-Calc simulation may show additional composition sets if global minimization is activated (LAVES#2, etc.)

Switching to another composition set typically causes errors and must be avoided. Depending on whether you are just close to a miscibility gap, or whether you really cross it, you either need to prevent switching using e.g. user limits, or you need to add further composition sets (or other phases) to the .ges5 file and include it into MICRESS.

Bernd

[CharMIC]

Dear Bernd,

Many thanks for the reply

I have looked at the TabLin out put. I can see sudden change in composition at 1 sec. This because Laves phase has been precipitated fully in the microstructure (Laves phase precipitate around 1460K and fully grow around 1400K in my simulations).
At 1 sec the temperature is 1028K

When the temperature continue drop, I see sudden changes in the compositions (eg. Nb wt%).

I have attached the file with this post. Could you please kindly check it and let me know I am making correct conclusions here before I start adding more elements in to the .GES5 file.

And Also could you kindly explain why I get this error at low temperatures and not at high temperature where laves has been completely formed?

BR
Chamara

[Bernd]

Hi Chamara,

it seems to be like I assumed - the Laves phase shows a miscibility gap at lower temperatures and has the tendency to form a Mo-rich phase instead of a Nb+Fe phase. If there is no experimental evidence that such a phase really occurs, you should try to suppress the formation by setting a proper concentration limit or a relative criterion in the section for stoichiometric phases:

limits 2 5
20.0
100.0

requires that Nb in phase 2 (Laves) always should be above 20 at%,

or

criterion_lower 2 1 4

makes sure that element 4 (Mo) is has always lower content (in at%) in Laves than in FCC.

If a criterion or a limit is violated, an error is thrown, e.g.

error = 10205 if a limit of element 5 in phase 2 was violated,

or error = 1020104 if a relative criterion of phase 2 and 1 was violated for component 4.

If the system can avoid these violations, this will help, otherwise, it is necessary to include an extra phase LAVES#2 with Mo as major component.

Bernd

[CharMIC]

Dear Bernd,

Many thanks for the detailed reply.

I have seen in the literature some EDS measurements done with TEM EDS. (https://link.springer.com/article/10.10 ... 016-1812-6)

There They have reported following compositions in LAVES (see the image also)

Nb wt % - 22 - 29 (nominal 5%)
Fe wt % - 12 -13 (nominal 18.5%)
Mo wt % - 10 - 11 (nominal 3%)

It seems that Mo content also high in Laves.

Therefore do I need to set limits for both Nb and Mo?

Also could you explain little bit more about the defining extra phase LAVES#2? In the database I am not able to find another LAVES phase? It only show C14_LAVES. (I used TCNI8 database)

BR
Chamara

[Bernd]

Hi Chamara,

When different composition sets of a phase like Laves are coming into play, it is important to first have a look on phase constitution:

Laves_Constitution.GIF (120.23 KiB) Viewed 9474 times

As you can see in the Thermo-Calc System Definer, C14_LAVES has two sublattices which accept all your elements but C.

In order to get a feeling which lattice constitutions could be stable, you then should make a Thermo-Calc equilibrium calculation close to your local conditions in MICRESS (e.g. interdendritic composition and T=800K):

Laves_Composition_Sets.GIF (99.44 KiB) Viewed 9474 times

In case of a single equilibrium calculation, you can evaluate the phase constitution of C14_LAVES in the Table Renderer. Here, it is important to suppress other phases which are metastable (like delta, sigma, etc.). In this (arbitrarily chosen) case you see that Thermo-Calc automatically has chosen two composition sets with arbitrary numbers. The constitution shows different sublattice site fractions for the elements in the different composition sets.

Thermo-Calc automatically creates new composition sets if global minimization is enabled, which is not possible (and also not wanted) in MICRESS. Therefore, it is necessary to create and correctly define those composition sets already when creating the .ges5 file.

Now, if problems with demixing of the phase compositions exist, like in your case, when just the "normal" C14_LAVES has been used, the user should proceed in the following order:

1.) Correctly define the default major components for the phase according to your knowledge or expectation.
When you create the .ges5 file, just before saving it while you are still inside the GES module, use AMEND_PHASE_DESCRIPTION and specify the phase name ("C14_LAVES"). Now, chose to amend MAJOR_CONSTITUENT, which allows you specifying the major constituent(s) for each sublattice. In case the C14_LAVES#3 is the one you prefer, you should specify Fe on the first and Nb and Mo on the second sublattice. This will assure that the start values for calculation of equilibria are set accordingly. You can control this choice through the MICRESS output "Start Composition for iteration of quasi-equilibrium" which is written to the screen output and .log file during initialisation.

2.) If setting the major constituents is not sufficient to prevent demixing, you should use limits or relative criteria in MICRESS for not allowing to enter into another composition set. Especially the limits should be used with care and only for one element which is the best to distinguish the composition sets. Please have in mind that limits are specified in at% in MICRESS.

3.) If you still have problems with demixing, then the other composition set(s) which cannot be prevented from forming seem to be necessary and should be included into the MICRESS simulation. Then you have to go back to Thermo-Calc and add the composition set to the .ges5 file (if not already present). Use AMEND_PHASE_DESCRIPTION with the suboption COMPOSITION_SET to create a new composition set according to your expectations.

Bernd

[CharMIC]

Hej Bernd,

Many many thanks for the detailed explanation.

I will try the tings that you have suggested. Is there any training course that MICRESS teach these advance features?

BR
Chamara

[Bernd]

Hej Chamara,

not yet, but at some point we will need an advanced training, once there are enough people who ask for it...

Bernd

[CharMIC]

One more thing Bernd.

Can we avoid this if we unchecked the global minimization and then create GES file?

[Bernd]

Avoid what?