Reg. Modeling of alpha-gamma transformation

[R.Hess]

Dear Bernd,
i also tried to simulate the austenite formation, but i cant reach a useful result. My target is, to simulate the formation of austenite with a high heating rate. Because of that, i thought it would be better to start the first simulation with a low heating rate to approximate to the targeted rate step by step.
I really have so many problems, that i think the only solution is to ask in this topic for help.

The first problem is, that if(!) Micress starts to calculate , the runtime is very very high. I almost have to wait 24h to get a result. Maybe you know why?

The second problem is, the results itself. I cant find the problem in my input file. All the important parameters (like mobility, surface energy, diffusion coefficient and activation energy) i got from literature and papers, where the same transformation was simulated before.

This is my input file:

#
# Automatic 'Driving File' written out by MICRESS.
#
#
#
# MICRESS binary
# ==============
# version number: 6.200 (Windows)
# compiled: Nov 26 2014
# compiler version: Intel 1400 20140805
# executable architecture: x64
# Thermo-Calc coupling: enabled
# Version: 7
# Link Date: Thu Nov 28 13:14:32 2013
# OS Name: WinNT
# Build Date: 6388
# Compiler: Intel(R) Visual Fortran Composer Version 12.1.3.300 Build 20120130
# OpenMP: disabled
# ('double precision' binary)
# permanent license
#
#
# Language settings
# =================
# Please select a language: 'English', 'Deutsch' or 'Francais'
English
#
#
# Flags and settings
# ==================
#
# Geometry
# --------
# Grid size?
# (for 2D calculations: CellsY=1, for 1D calculations: CellsX=1, CellsY=1)
# Cells in X-direction (CellsX):
250
# Cells in Y-direction (CellsY):
1
# Cells in Z-direction (CellsZ):
250
# Cell dimension (grid spacing in micrometers):
# (optionally followed by rescaling factor for the output in the form of '3/4')
0.25000
#
# Flags
# -----
# Type of coupling?
# Options: phase concentration temperature temp_cyl_coord
# [stress] [stress_coupled] [flow] [flow_coarse] [dislocation]
concentration
# Type of potential?
# Options: double_obstacle multi_obstacle [fd_correction]
multi_obstacle fd_correction
# Enable one dimensional far field approximation for diffusion?
# Options: 1d_far_field no_1d_far_field
no_1d_far_field
# Shall an additional 1D field be defined in z direction
# for temperature coupling?
# Options: no_1d_temp 1d_temp 1d_temp_cylinder 1d_temp_polar [kin. Coeff]
# kin. Coeff: Kinetics of latent heat release (default is 0.01)
no_1d_temp
#
# Phase field data structure
# --------------------------
# Coefficient for initial dimension of field iFace
# [minimum usage] [target usage]
0.1
# Coefficient for initial dimension of field nTupel
# [minimum usage] [target usage]
0.1
#
#
# Restart options
# ===============
# Restart using old results?
# Options: new restart [reset_time | structure_only]
restart structure_only
1
0
Results/GammaAlphaPearlite_42CrMo4_TQ
#
#
# Name of output files
# ====================
# Name of result files?
Heating/Results/FerritPerlit_Gamma_2
# Overwrite files with the same name?
# Options: overwrite write_protected append
# [zipped|not_zipped|vtk]
# [unix|windows|non_native]
overwrite
#
#
# Selection of the outputs
# ========================
# [legacy|verbose|terse]
# Finish selection of outputs with 'end_of_outputs'.
terse
out_restart
out_grains
out_phases
out_fraction 1 2
tab_fractions
out_interface
out_driv_force
tab_grains
out_conc
out_conc_phase 1 | 2
out_mobility
tab_lin
tab_log 1.
# out_relin
# out_curvature
# out_velocity
# tab_vnm
# tab_grain_data
out_temp
# tab_conc
# out_recrystall
# tab_recrystall
# out_disloc
# out_miller
# out_orientation
# tab_orientation [rotmat]
end_of_outputs
#
#
# Time input data
# ===============
# Finish input of output times (in seconds) with 'end_of_simulation'
# 'regularly-spaced' outputs can be set with 'linear_step'
# or 'logarithmic_step' and then specifying the increment
# and end value
# ('automatic_outputs' optionally followed by the number
# of outputs can be used in conjuction with 'linear_from_file')
# 'first' : additional output for first time-step
# 'end_at_temperature' : additional output and end of simulation at given temperature
#
linear_step 1 20
linear_step 2 50
linear_step 5 100
end_at_temperature 1713
end_of_simulation
# Time-step?
# Options: fix ...[s] automatic automatic_limited
automatic_limited
# Options: constant from_file
constant
# Limits: (real) min./s, [max./s], [phase-field factor], [segregation factor]
1.E-4 1.0
# Coefficient for phase-field criterion 1.00
# Coefficient for segregation criterion 0.900
# Number of steps to adjust profiles of initially sharp interfaces [exclude_inactive]?
10
#
#
# Phase data
# ==========
# Number of distinct solid phases?
3
#
# Data for phase 1:
# -----------------
# Simulation of recrystallisation in phase 1?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 1 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
isotropic
# Should grains of phase 1 be reduced to categories?
# Options: categorize no_categorize
no_categorize
#
# Data for phase 2:
# -----------------
# [identical phase number]
# Simulation of recrystallisation in phase 2?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 2 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
isotropic
# Should grains of phase 2 be reduced to categories?
# Options: categorize no_categorize
no_categorize
#
# Data for phase 3:
# -----------------
# [identical phase number]
# Simulation of recrystallisation in phase 3?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 3 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
anisotropic
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Should grains of phase 3 be reduced to categories?
# Options: categorize no_categorize
no_categorize
#
# Orientation
# -----------
# How shall grain orientations be defined?
# Options: angle_2d euler_zxz angle_axis miller_indices quaternion
angle_2d
#
#
# Grain input
# ===========
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
random
# Integer for randomization?
23457
# Number of different types of grains?
0
#
#
# Data for further nucleation
# ===========================
# Enable further nucleation?
# Options: nucleation nucleation_symm no_nucleation [verbose|no_verbose]
nucleation
# Additional output for nucleation?
# Options: out_nucleation no_out_nucleation
no_out_nucleation
#
# Number of types of seeds?
4
#
# Input for seed type 1:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
triple
# Phase of new grains (integer) [unresolved|add_to_grain]?
1
# Reference phase (integer) [min. and max. fraction (real)]?
2
# Substrate phase [2nd phase in interface]?
2
# maximum number of new nuclei 1?
250
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
0
# Shield effect:
# Shield time [s] [shield phase or group number] ?
0.5
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
1
# Nucleation range
# min. nucleation temperature for seed type 1 [K]
900
# max. nucleation temperature for seed type 1 [K]
1200
# Time between checks for nucleation? [s]
constant
0.2
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Input for seed type 2:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
interface
# Phase of new grains (integer) [unresolved|add_to_grain]?
1
# Reference phase (integer) [min. and max. fraction (real)]?
2
# Substrate phase [2nd phase in interface]?
# (set to 1 to disable the effect of substrate curvature)
3
# maximum number of new nuclei 2?
500
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
0
# Shield effect:
# Shield time [s] [shield phase or group number] ?
0.5
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
1
# Nucleation range
# min. nucleation temperature for seed type 2 [K]
900
# max. nucleation temperature for seed type 2 [K]
1200
# Time between checks for nucleation? [s]
constant
0.2
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Input for seed type 3:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
triple
# Phase of new grains (integer) [unresolved|add_to_grain]?
1
# Reference phase (integer) [min. and max. fraction (real)]?
3
# Substrate phase [2nd phase in interface]?
3
# maximum number of new nuclei 1?
250
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
0
# Shield effect:
# Shield time [s] [shield phase or group number] ?
0.5
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
1
# Nucleation range
# min. nucleation temperature for seed type 1 [K]
900
# max. nucleation temperature for seed type 1 [K]
1200
# Time between checks for nucleation? [s]
constant
0.2
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Input for seed type 4:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
interface
# Phase of new grains (integer) [unresolved|add_to_grain]?
1
# Reference phase (integer) [min. and max. fraction (real)]?
3
# Substrate phase [2nd phase in interface]?
# (set to 1 to disable the effect of substrate curvature)
2
# maximum number of new nuclei 2?
500
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
0
# Shield effect:
# Shield time [s] [shield phase or group number] ?
0.5
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
1
# Nucleation range
# min. nucleation temperature for seed type 2 [K]
900
# max. nucleation temperature for seed type 2 [K]
1200
# Time between checks for nucleation? [s]
constant
0.2
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Max. number of simultaneous nucleations?
# ----------------------------------------
# (set to 0 for automatic)
0
#
# Shall metastable small seeds be killed?
# ---------------------------------------
# Options: kill_metastable no_kill_metastable
no_kill_metastable
#
#
# Phase interaction data
# ======================
#
# Data for phase interaction 0 / 1:
# ---------------------------------
# Simulation of interaction between phase 0 and 1?
# Options: phase_interaction no_phase_interaction
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control]
no_phase_interaction
#
# Data for phase interaction 0 / 2:
# ---------------------------------
# Simulation of interaction between phase 0 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control]
no_phase_interaction
#
# Data for phase interaction 0 / 3:
# ---------------------------------
# Simulation of interaction between phase 0 and 3?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control]
no_phase_interaction
#
# Data for phase interaction 1 / 1:
# ---------------------------------
# Simulation of interaction between phase 1 and 1?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction
# Type of surface energy definition between phases 1 and 1?
# Options: constant temp_dependent
constant
# Surface energy between phases 1 and 1? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
0.76E2
# Type of mobility definition between phases 1 and 1?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 1 and 1 [ min. value ] [cm**4/(Js)] ?
0.05E-11
#
# Data for phase interaction 1 / 2:
# ---------------------------------
# Simulation of interaction between phase 1 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction redistribution_control
# 'DeltaG' options: default
# avg ... [] max ... [J/cm**3] smooth ... [degrees] noise ... [J/cm**3]
avg 0. smooth 45
# I.e.: avg +0.00
# Type of surface energy definition between phases 1 and 2?
# Options: constant temp_dependent
constant
# Surface energy between phases 1 and 2? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
0.72E2
# Type of mobility definition between phases 1 and 2?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 1 and 2 [ min. value ] [cm**4/(Js)] ?
2.20000E-11
#
# Data for phase interaction 1 / 3:
# ---------------------------------
# Simulation of interaction between phase 1 and 3?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control]
phase_interaction
# 'DeltaG' options: default
# avg ... [] max ... [J/cm**3] smooth ... [degrees] noise ... [J/cm**3]
avg 0.5 max 500.
# I.e.: avg +0.50 smooth +0.0 max +5.00000E+02
# Type of surface energy definition between phases 1 and 3?
# Options: constant temp_dependent
constant
# Surface energy between phases 1 and 3? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
0.67E2
# Type of mobility definition between phases 1 and 3?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 1 and 3 [ min. value ] [cm**4/(Js)] ?
1.00000E-11
# Is interaction isotropic?
# Optionen: isotropic anisotropic [harmonic_expansion]
isotropic
#
# Data for phase interaction 2 / 2:
# ---------------------------------
# Simulation of interaction between phase 2 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction
# Type of surface energy definition between phases 2 and 2?
# Options: constant temp_dependent
constant
# Surface energy between phases 2 and 2? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
0.76E2
# Type of mobility definition between phases 2 and 2?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 2 and 2 [ min. value ] [cm**4/(Js)] ?
3.5E-11
#
# Data for phase interaction 2 / 3:
# ---------------------------------
# Simulation of interaction between phase 2 and 3?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control]
phase_interaction
# 'DeltaG' options: default
# avg ... [] max ... [J/cm**3] smooth ... [degrees] noise ... [J/cm**3]
avg 0.5 max 500.
# I.e.: avg +0.50 smooth +0.0 max +5.00000E+02
# Type of surface energy definition between phases 2 and 3?
# Options: constant temp_dependent
constant
# Surface energy between phases 2 and 3? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
0.71E2
# Type of mobility definition between phases 2 and 3?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 2 and 3 [ min. value ] [cm**4/(Js)] ?
0.5E-11
# Is interaction isotropic?
# Optionen: isotropic anisotropic [harmonic_expansion]
isotropic
#
# Data for phase interaction 3 / 3:
# ---------------------------------
# Simulation of interaction between phase 3 and 3?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control]
no_phase_interaction
#
#
# Concentration data
# ==================
# Number of dissolved constituents? (int)
2
# Type of concentration?
# Options: atom_percent (at%)
# weight_percent (wt%)
weight_percent
# Concentration data
# ==================
#
#
# Diffusion Data
# --------------
# ["Terse Mode": Each line starts with component number and phase number]
# Options: diagonal [x] multi [y(1..k)]
# x: one of the characters "n", "d", "g", "l", "z", "i", "I", or "f"
# y: chain of "n", "d", "g", "l", "z", or "f" (for each component)
# default: "g" resp. "gggg..."
# Rem: "n":no diffusion, "d": input, "f": T-dep. from file
# "i":infinite, "I": infinite in each grain
# from database: "g": global, "l": local, "z" global z-segmented
# Extra option [+b] for grain-boundary diffusion
# Extra line option (prefactor on time step): cushion <0-1>
# Extra line option: infinite_limit [cm**2/s]
# Extra line option: maxfactor_local [real > 1.0] (default: 10.0)
# Finish input of diffusion data with 'end_diffusion_data'.
#
# How shall diffusion of component 1 in phase 0 be solved?
diagonal n
# How shall diffusion of component 1 in phase 1 be solved?
diagonal d
#Diff.Coefficient:
#Prefactor?(real) [cm**2/s]
0.15
# Activation energy? (Real) [J/mol]
140000
# How shall diffusion of component 1 in phase 2 be solved?
diagonal d
#Diff.Coefficient:
#Prefactor?(real) [cm**2/s]
2.2
# Activation energy? (Real) [J/mol]
140000
# How shall diffusion of component 1 in phase 3 be solved?
diagonal d
#Diff.Coefficient:
#Prefactor?(real) [cm**2/s]
2.2
# Activation energy? (Real) [J/mol]
118400.1332200
# How shall diffusion of component 2 in phase 0 be solved?
diagonal n
# How shall diffusion of component 2 in phase 1 be solved?
diagonal n
# How shall diffusion of component 2 in phase 2 be solved?
diagonal n
# How shall diffusion of component 2 in phase 3 be solved?
diagonal n
#
#
#
#
# Phase diagram - input data
# ==========================
#
# List of phases and components which are stoichiometric:
# phase and component(s) numbers
# List of concentration limits (at%):
# <Limits>, phase number and component number
# List for ternary extrapolation (2 elements + main comp.):
# <interaction>, component 1, component 2
# Switches: <stoich_enhanced_{on|off}> <solubility_{on|off}>
# End with 'no_more_stoichio' or 'no_stoichio'
interaction
no_stoichio
#
#
#
#
# Is a thermodynamic database to be used?
# Options: database database_verbose no_database
no_database
#
# Input of the phase diagram of phase 1 and phase 2:
# --------------------------------------------------
# Which phase diagram is to be used?
# Options: linear linearTQ
linear
# Temperature of reference point? [K]
1023
# Entropy of fusion between phase 1 and 2 ? [J/(cm**3 K)]
2.123545455E-6
# Input of the concentrations at reference points
# Reference point 1: Concentration of component 1 in phase 1 ? [wt%]
0.61
# Reference point 2: Concentration of component 1 in phase 2 ? [wt%]
0.016
# Reference point 1: Concentration of component 2 in phase 1 ? [wt%]
0.901
# Reference point 2: Concentration of component 2 in phase 2 ? [wt%]
0.901
# Input of the slopes at reference points
# Slope m = dT/dC at reference point 1, component 1 ? [K/wt%]
-154.0
# Slope m = dT/dC at reference point 2, component 1 ? [K/wt%]
-9909
# Slope m = dT/dC at reference point 1, component 2 ? [K/wt%]
0.001
# Slope m = dT/dC at reference point 2, component 2 ? [K/wt%]
0.001
# Please specify the redistribution behaviour of each component:
# Format: forward [backward]
# Options: nple para paratq normal [mob_corr] atc [mob_corr] [verbose]
# Component 1
normal
# Component 2
nple
#
#
# Input of the phase diagram of phase 1 and phase 3:
# --------------------------------------------------
# Which phase diagram is to be used?
# Options: linear linearTQ
linear
# Temperature of reference point? [K]
1023
# Entropy of fusion between phase 1 and 2 ? [J/(cm**3 K)]
4.0225E-3
# Input of the concentrations at reference points
# c0 of component 1 in phase 1 ? [wt%]
0.82
# c0 of component 1 in phase 3 ? [wt%]
6.69
# c0 of component 2 in phase 1 ? [wt%]
0.9
# c0 of component 2 in phase 3 ? [wt%]
0.9
# m of component 1 in phase 1 ? [K/wt%]
353
# m of component 1 in phase 3 ? [K/wt%]
10000
# m of component 2 in phase 1 ? [K/wt%]
0.001
# m of component 2 in phase 3 ? [K/wt%]
0.001
#
# Input of the phase diagram of phase 2 and phase 3:
# --------------------------------------------------
# Which phase diagram is to be used?
# Options: linear linearTQ
linear
# Temperature of reference point? [K]
1023
# Entropy of fusion between phase 2 and 3 ? [J/(cm**3 K)]
4.0225E-3
# c0 of component 1 in phase 2 ? [wt%]
0.024
# c0 of component 1 in phase 3 ? [wt%]
6.69
# c0 of component 2 in phase 2 ? [wt%]
5.95417E-02
# c0 of component 2 in phase 3 ? [wt%]
1.0780
# m of component 1 in phase 2 ? [K/wt%]
5814
# m of component 1 in phase 3 ? [K/wt%]
10000
# m of component 2 in phase 2 ? [K/wt%]
-0.001
# m of component 2 in phase 3 ? [K/wt%]
-0.001
#
bottom_temperature
# Initial concentrations
# ======================
# How shall initial concentrations be set?
# Options: input equilibrium from_file [phase number]
input
# Initial concentration of component 1 in phase 0 ? [wt%]
0
# Initial concentration of component 1 in phase 1 ? [wt%]
0.4
# Initial concentratin of component 1 in Phase 2 ? [wt%]
0
# Initial concentratin of component 1 in Phase 3 ? [wt%]
0.9
#
# Initial concentration of component 2 in phase 0 ? [wt%]
0.9
# Initial concentration of component 2 in phase 1 ? [wt%]
0.9
# Initial concentratin of component 2 in Phase 2 ? [wt%]
0.9
# Initial concentratin of component 2 in Phase 3 ? [wt%]
0.9
#
# Parameters for latent heat and 1D temperature field
# ===================================================
# Simulate release of latent heat?
# Options: lat_heat lat_heat_3d[matrix phase] no_lat_heat no_lat_heat_dsc
no_lat_heat
#
#
# Boundary conditions
# ===================
# Type of temperature trend?
# Options: linear linear_from_file profiles_from_file
linear
# Number of connecting points? (integer)
0
# Initial temperature at the bottom? (real) [K]
293
# Temperature gradient in z-direction? [K/cm]
0.0000
# Cooling rate? [K/s]
15
# Moving-frame system in z-direction?
# Options: moving_frame no_moving_frame
no_moving_frame
#
# Boundary conditions for phase field in each direction
# Options: i (insulation) s (symmetric) p (periodic/wrap-around)
# g (gradient) f (fixed) w (wetting)
# Sequence: W E (S N, if 3D) B T borders
pppp
#
# Boundary conditions for concentration field in each direction
# Options: i (insulation) s (symmetric) p (periodic/wrap-around) g (gradient) f (fixed)
# Sequence: W E (S N, if 3D) B T borders
pppp
# Unit-cell model symmetric with respect to the x/y diagonal plane?
# Options: unit_cell_symm no_unit_cell_symm
no_unit_cell_symm
#
#
# Other numerical parameters
# ==========================
# Phase minimum?
1.00E-06
# Interface thickness (in cells)?
3
#
#



As it can be seen, i want to start the simulation from the last step of the gamma_alpha_example, because of the Ferrite/Perlite structure. I changed the concentrations of the example, because i wanted to fit it with our workpiece material.

Here you can see my nonsensical results:



To sum up, it would be great if you can help me with this two problems:
-huge runtime
-which parameters are nonsense in the inputfile and occur such a result


Raphael

[Bernd]

Dear Raphael,

I don't understand exactly what your phases represent and which is your initial structure. However, there are several unreasonably chosen parameters which easily explain the trouble you have:

- interface energies are out of range - typical values are around 1.E-5 J/cm2
- interface mobility values are very small, perhaps wrong units?
- in the linearized phase diagram description you have chosen very small slopes for component 2. Do you want to mimic para-equilibrium behavior? Why you have chosen "nple" at the same time? What is your intention here, and why don't you use TQ coupling?
- some of your initial compositions are 0 which should be avoided if they are not stoichiometric (no solubility in the corresponding phase). This may hurt, at least if the phase already exists in the initial microstructure.
- your simulation starts at room temperature which is not a good idea. At this temperature, diffusivities are extremely low, and it is quite a bit of work to make this running without numerical problems. Anyway, nothing is happening at these low temperatures, so why not starting at higher temperatures, just below when your transformation starts?

Bernd

[R.Hess]

Dear Bernd,
i´m sorry for my late reply and for my vague question.

I try to model the austenite formation of a low carbon steel. My first problem was to represent the ferrite-pearlite structure. So i thought it would be a good idea, to use the final structure of the GammaAlphaPearlite-Example as the initial structure of my "heating process". The phases in my input file are the same phases like in the example. 1- Austenite , 2-Ferrite , 3-Cementite. Now i hope it is easier to understand.

1.) i matched the surface energys( the order of magnitude). now the result is a bit better, but nevertheless, my result is nonsense(later i will explain why)

2.) i chose that small mobility values, because this transition is diffusion-driven - so i thought that the mobility has to be very very small. furthermore, in the paper of M.Militzer, they chose the same order of magnitude ( doi: 10.4028/www.scientific.net/SSP.172-174.1050 ).

3.)yes, thats what i wanted to modell. i´m working since september´16 with micress, and i dont really know what "nple" means
i dont use TQ, because i think that the calculation time increases radically. additional, my target is to model very fast heating (about 1000K/s) - is a TQ_coupled simulation capable to run it? however, i tried it - the input file you can see below


4&5 ) i changed the two things you mentioned


On the whole, the simulation output looks much better - but it isn´t still right.
In my phase outout i can observe, that the seeds are set - at the right temperature and at the right places - but those seeds don't grow. they stay at their initial size. And this is nonsense. Of course, they have to grow and use up the whole ferrite/pearlite structure. Do you know what the problem is, after analysing my input file?
i am very grateful for you help.

Raphael

[Bernd]

Hi Rafael,

looking through your input file I find that in many places the time-scales do not fit to the fast heating which you apply. Bear in mind that your simulation stops after 1.25 seconds after reaching 1700K!

a) "# Selection of the outputs": tab_log 1.
This means you will get just 1 output to the .TabL, .TabP etc. text files. You should much more frequently (e.g. tab_log 0.001)

b) "# Time input data": The same for your main (graphical) outputs...

c) # Data for further nucleation: your checking interval of 0.25 s is much too big

d) "# Phase diagram - input data": The updating interval for global relinearisation should be smaller - e.g. 0.01 seconds.

Furthermore, if you set e.g. the interface mobility of fcc/bcc to 1.E-15, the interface will not move at all during the short time of simulation. Anyway, this transformation should not be limited by diffusion of the substitutional element (component2)(otherwise it would not move at all...) but by diffusion of carbon. For "overrunning" Mn, there are two modes (nple or paraequilibrium) where you need to select one.
With the new MICRESS version 6.3 I would advise you to use the automatic mobility correction "mob_corr":

#
# Data for phase interaction 1 / 2:
# ---------------------------------
# Simulation of interaction between phase 1 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction redistribution_control
...
# Kinetic coefficient mu between phases 1 and 2 [ min. value ] [cm**4/(Js)] ?
1.0E-3 !High enough for diffusion controlled, will be reduced by mob_corr
...

# Input of the phase diagram of phase 1 and phase 2:
# --------------------------------------------------
# Which phase diagram is to be used?
# Options: database [local|global|globalF][start_value_{1|2}] linear linearTQ
database global
# Relinearisation mode for interface 1 / 2
# Options: automatic manual from_file none
none
# Please specify the redistribution behaviour of each component:
# Format: forward [backward]
# Options: nple para paratq normal [mob_corr] atc [mob_corr] [verbose]
# Component 1
normal mob_corr
# Component 2
nple
...
# Please specify a criterion for the direction
# of the direction of the redistribution model:
# Options: local_velocity average_velocity bottom_temperature
bottom_temperature
...

Finally, the initial grain radius in the nucleation types is put to 0.5µm which is bigger than a grid spacing. This value should typically be 0, in some cases one may chose something >0, but always smaller than the grid spacing.

Bernd

[R.Hess]

Hi Bernd,

thank you for your helpful answer. My simulation-output looks much better.
Nevertheless i got two last questions(hopefully "last" ).
I matched the time steps, the mobility (like you mentioned above) and furthermore i increased the cooling rate.
Now the seeds austenite seeds are growing and almost everything looks good, but the austenite grains dont grow into the ferrite bulk. What could be the problem in this case? by analysing the conc1_output, i can oberserve that carbon does not diffuse during this heating process. maybe that could be the problem? Carbon does not diffuse into ferrite and for that reason it is impossible for austenite to use up ferrite?

my second question is, when the seeds were set, the grain boudaries (phase -1 in the output) seems to be very big. And in addition to this, between the ferrite-bulk and the new austenite grain, a grain boundary doesn´t form. This problem can also be observed at the end of the simulation : too big grain boundaries between austenite-austenite and missing grain boundaries between ferrite - austenite.

In the attachement you can see my "new" input file and a picture of the final phase_output. In the picture you can observe what i tried to describe above.

kind regards

raphael

[Bernd]

Dear Raphael,

Why did you make heating up even faster? I guess, at such a high heating rate there is no diffusion anymore, and I am not sure what should happen...

There is already a diffuse region which consists of pearlite. That is the initial microstructure which you read from the .rest file. Thus, the blue region is like it should be, completely interface. The lacking interface between ferrite and austenite is probably a broken interface due to the extreme heating rate.

Another problem is that you don't let the pearlite dissolve by setting the mobility for that to a too small value. Furthermore, you limit the numerical time-step to a range from 1.E-4 to 1.0 seconds which is contradictory to your time intervals for e.g. for checking for nucleation.

Please go back to 1000 K/s heating which is already enough and set the time intervals properly. You do not need so extremely high rates for nucleation and updating thermodynamic and diffusion data.
Then, we must find out whether the length-scale is sufficiently small for that heating rate.

Bernd

[R.Hess]

Dear Bernd,
i increased the heating rate, because our final target are heating rates about 1E6. But it doesn´t matter in this case and for this simulation.
I decreased the heatingrate to 1250K/s. Furthermore i matched the time intervals. Nevertheless, i nearly receive the same result as before. Except the interfaces between the austenite grains. They are smaller and look better.
But the interface between ferrite and austenite is still missing.


You mentioned the length-scale. Do you mean, that because of the insufficient time (or too long length scale) the carbon atoms cant "reach" the ferrite bulk? If that is the case, i have a complete different approach:

In the "new" examples, you (or someone else ) modeled widmanstätten growth(GammaAlpha_FeC_Acicular). or rather said, ferrite was represented as "needles". Therefore, i tried to combine this mentioned example with GammaAlphaPearlite. If it would possible to implement a third, unresolved phase (cementite), that only exist around the interfaces of ferrite. that would represent a correct ferrite/pearlite structure? Furhtermore, the distances between the "ferrite-bulks" are much smaller. Therefore, if i restart the "heating" based on this described simulation, it should be possible that carbon diffuses into ferrite.

But:
i cant handle it with the third phase. i thought it would be easy and i can "copy and paste" all necessary input data from GammaAlphaPearlite to GammaAlpha_Acicular. But the result isn´t what i hoped it would be. There is still retained austenite and the carbon doesn´t arrange at the ferrite-boundaries.

What do you think , what would be the better solution to achieve the aim? Can you help me in both cases, or is the second approach completely nonsense?

Raphael

[Bernd]

Dear Raphael,

I think it is not a good concept to start from a coarse-grained microstructure with a diffuse pearlite phase, and then apply extremely high heating rates where diffusion will only take place at a very short length-scale. The system and the question you raise are complicated enough so that you should keep everything else as simple as possible - at least at the beginning. At the moment you have too many problems at the same time which cannot be controlled. Introducing even more complications like mis-orientations and acicular growth would make it even worse...

I would advise you to start for example with 3 ferrite grains with a cementite particle at the triple junction in a domain of e.g. 1µm x 1µm. Then start with small heating rates, nucleate austenite at the interface between cementite and ferrite, and see what happens.
Afterwards, once this is running in reasonable way, and you had time to understand the problems of this "simple" approach (it is still complicated enough!), you can start raising the cooling rate and see how far you can get.

Bernd

[Belo]

Hi there,

I would like to simulate a complete gamma-alpha phase transformation starting with a domain of 1004 um x 1004 um (251 cells and 4 mesh size) . To do so, I based on the example file where there are only 9 initial grains and created an initial microstructure of EQAD = 65um and a narrow size distribution (1.26). Now I need to nucleate ferrite grains from this structure until it fully covers the austenite grains (the ferrite grain should be bigger than the initial austenite ones). However, I had no success so far on that and I don't know what I am doing wrong (please, check the results I am getting). I tried to change to 1001 cells and 1 mesh size but there was an error. I dont know why the grains are not growing and why they are concentrated in specific locations. I also tried to use "region" in the whole domain instead of "triple juntion, interface and bulk" but also without success. I would be glad if you could guide me through a solution. FInd below my input file:


# Geometry
# --------
# Grid size?
# (for 2D calculations: CellsY=1, for 1D calculations: CellsX=1, CellsY=1)
# Cells in X-direction (CellsX):
251
# Cells in Y-direction (CellsY):
1
# Cells in Z-direction (CellsZ):
251
# Cell dimension (grid spacing in micrometers):
# (optionally followed by rescaling factor for the output in the form of '3/4')
4
#
# Flags
# -----
# Type of coupling?
# Options: phase concentration temperature temp_cyl_coord
# [stress] [stress_coupled] [flow] [flow_coarse] [dislocation]
concentration
# Type of potential?
# Options: double_obstacle multi_obstacle [fd_correction]
multi_obstacle fd_correction
# Enable one dimensional far field approximation for diffusion?
# Options: 1d_far_field no_1d_far_field
no_1d_far_field
# Shall an additional 1D field be defined in z direction
# for temperature coupling?
# Options: no_1d_temp 1d_temp 1d_temp_cylinder 1d_temp_polar [kin. Coeff]
# kin. Coeff: Kinetics of latent heat release (default is 0.01)
no_1d_temp
#
# Phase field data structure
# --------------------------
# Coefficient for initial dimension of field iFace
# [minimum usage] [target usage]
0.1
# Coefficient for initial dimension of field nTupel
# [minimum usage] [target usage]
0.1
#
#
# Restart options
# ===============
# Restart using old results?
# Options: new restart [reset_time | structure_only]
new
#
#
# Name of output files
# ====================
# Name of result files?
Results_Gamma_Alpha/Gamma_Alpha
# Overwrite files with the same name?
# Options: overwrite write_protected append
# [zipped|not_zipped|vtk]
# [unix|windows|non_native]
overwrite
#
#
# Selection of the outputs
# ========================
# [legacy|verbose|terse]
# Finish selection of outputs with 'end_of_outputs'.
terse
out_restart
out_grains
out_phases
out_fraction 1 2
tab_fractions
out_interface
out_driv_force
out_curvature
out_velocity
tab_grains
tab_vnm
tab_grain_data
out_conc
out_conc_phase 1 | 2
out_mobility
out_orientation
tab_orientation
tab_lin
tab_log 1.
# out_relin
# out_temp
# tab_conc
# out_recrystall
# tab_recrystall
# out_disloc
# out_miller
end_of_outputs
#
#
# Time input data
# ===============
# Finish input of output times (in seconds) with 'end_of_simulation'
# 'regularly-spaced' outputs can be set with 'linear_step'
# or 'logarithmic_step' and then specifying the increment
# and end value
# ('automatic_outputs' optionally followed by the number
# of outputs can be used in conjuction with 'linear_from_file')
# 'first' : additional output for first time-step
# 'end_at_temperature' : additional output and end of simulation
# at given temperature
linear_step 1.0 6.0
linear_step 2.0 10.0
linear_step 5.0 30.0
linear_step 10.0 100.0
linear_step 25.0 300.0
end_of_simulation
# Time-step?
# Options: fix ...[s] automatic automatic_limited
automatic_limited
# Options: constant from_file
constant
# Limits: (real) min./s, [max./s], [phase-field factor], [segregation factor]
1.E-4 1.0
# Coefficient for phase-field criterion 1.00
# Coefficient for segregation criterion 0.900
# Number of steps to adjust profiles of initially sharp interfaces [exclude_inactive]?
20
#
#
# Phase data
# ==========
# Number of distinct solid phases?
2
#
# Data for phase 1:
# -----------------
# Simulation of recrystallisation in phase 1?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 1 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
anisotropic
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Should grains of phase 1 be reduced to categories?
# Options: categorize no_categorize
no_categorize
#
# Data for phase 2:
# -----------------
# [identical phase number]
# Simulation of recrystallisation in phase 2?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 2 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
anisotropic
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Should grains of phase 2 be reduced to categories?
# Options: categorize no_categorize
no_categorize
#
# Orientation
# -----------
# How shall grain orientations be defined?
# Options: angle_2d euler_zxz angle_axis miller_indices quaternion
euler_zxz
#
#
# Grain input
# ===========
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
random
# Integer for randomization?
123457
# Number of different types of grains?
1
# Number of grains of type 1?
299
# Input for grain type 1
# ----------------------
# Geometry of grain type 1
# Options: round rectangular elliptic
round
# Minimal value of x-coordinates? [micrometers]
0.00000
# Maximal value of x-coordinates? [micrometers]
1004.00
# Minimal value of z-coordinates? [micrometers]
0.00000
# Maximal value of z-coordinates? [micrometers]
1004.00
# Minimum grain radius? [micrometers]
49.0000
# Maximum grain radius? [micrometers]
49.0000
# Shall grain type 1 be stabilized or shall
# an analytical curvature description be applied?
# Options: stabilisation analytical_curvature
stabilisation
# Should the Voronoi criterion for grains of type 1 be applied?
# Options: voronoi no_voronoi
voronoi
# Phase number for grain type 1? (int)
1
# Determination of grain orientations?
# Options: random fix fix_direction
random
# Minimal distance between grains (real) [micrometers]?
50.000
#
#
# Data for further nucleation
# ===========================
# Enable further nucleation?
# Options: nucleation nucleation_symm no_nucleation [verbose|no_verbose]
nucleation
# Additional output for nucleation?
# Options: out_nucleation no_out_nucleation
no_out_nucleation
#
# Number of types of seeds?
3
#
# Input for seed type 1:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
triple
# Phase of new grains (integer) [unresolved|add_to_grain]?
2
# Reference phase (integer) [min. and max. fraction (real)]?
1
# Substrate phase [2nd phase in interface]?
1
# maximum number of new nuclei 1?
250
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
50.000
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
random
# Shield effect:
# Shield time [s] [shield phase or group number] ?
500.000
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
5.000
# Nucleation range
# min. nucleation temperature for seed type 1 [K]
0.000000
# max. nucleation temperature for seed type 1 [K]
1200.000
# Time between checks for nucleation? [s]
1.0100
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Input for seed type 2:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
interface
# Phase of new grains (integer) [unresolved|add_to_grain]?
2
# Reference phase (integer) [min. and max. fraction (real)]?
1
# Substrate phase [2nd phase in interface]?
# (set to 1 to disable the effect of substrate curvature)
1
# maximum number of new nuclei 2?
500
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
50.000
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
random
# Shield effect:
# Shield time [s] [shield phase or group number] ?
500.000
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
5.000
# Nucleation range
# min. nucleation temperature for seed type 2 [K]
0.000000
# max. nucleation temperature for seed type 2 [K]
1200.000
# Time between checks for nucleation? [s]
1.0100
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Input for seed type 3:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
bulk
# Phase of new grains (integer) [unresolved|add_to_grain]?
2
# Reference phase (integer) [min. and max. fraction (real)]?
1
# Which nucleation model shall be used?
# Options: seed_undercooling seed_density
seed_undercooling
# maximum number of new nuclei 3?
500
# Grain radius [micrometers]?
0.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
50.000
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
random
# Shield effect:
# Shield time [s] [shield phase or group number] ?
500.000
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
5.000
# Nucleation range
# min. nucleation temperature for seed type 3 [K]
0.000000
# max. nucleation temperature for seed type 3 [K]
1200.000
# Time between checks for nucleation? [s]
1.0100
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Max. number of simultaneous nucleations?
# ----------------------------------------
# (set to 0 for automatic)
0
#
# Shall metastable small seeds be killed?
# ---------------------------------------
# Options: kill_metastable no_kill_metastable
kill_metastable
#
#
# Phase interaction data
# ======================
#
# Data for phase interaction 0 / 1:
# ---------------------------------
# Simulation of interaction between phase 0 and 1?
# Options: phase_interaction no_phase_interaction
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
no_phase_interaction
#
# Data for phase interaction 0 / 2:
# ---------------------------------
# Simulation of interaction between phase 0 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
no_phase_interaction
#
# Data for phase interaction 1 / 1:
# ---------------------------------
# Simulation of interaction between phase 1 and 1?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction
# Type of surface energy definition between phases 1 and 1?
# Options: constant temp_dependent
constant
# Surface energy between phases 1 and 1? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
2.00000E-05
# Type of mobility definition between phases 1 and 1?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 1 and 1 [ min. value ] [cm**4/(Js)] ?
1.00000E-05
# Shall misorientation be considered?
# Options: misorientation no_misorientation [transition LAB/HAB in degree]
no_misorientation
#
# Data for phase interaction 1 / 2:
# ---------------------------------
# Simulation of interaction between phase 1 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction redistribution_control
# 'DeltaG' options: default
# avg ... [] max ... [J/cm**3] smooth ... [degrees] noise ... [J/cm**3]
avg 0. smooth 45
# I.e.: avg +0.00
# Type of surface energy definition between phases 1 and 2?
# Options: constant temp_dependent
constant
# Surface energy between phases 1 and 2? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
2.0000E-05
# Type of mobility definition between phases 1 and 2?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 1 and 2 [ min. value ] [cm**4/(Js)] ?
2.20000E-06
# Shall misorientation be considered?
# Options: misorientation no_misorientation [transition LAB/HAB in degree]
no_misorientation
# Is interaction isotropic?
# Optionen: isotropic anisotropic [harmonic_expansion]
isotropic
#
# Data for phase interaction 2 / 2:
# ---------------------------------
# Simulation of interaction between phase 2 and 2?
# Options: phase_interaction no_phase_interaction identical phases nb
# [standard|particle_pinning[_temperature]|solute_drag]
# | [redistribution_control] or [no_junction_force|junction_force]
phase_interaction
# Type of surface energy definition between phases 2 and 2?
# Options: constant temp_dependent
constant
# Surface energy between phases 2 and 2? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
2.00000E-05
# Type of mobility definition between phases 2 and 2?
# Options: constant temp_dependent dg_dependent thin_interface_correction [fixed_minimum]
constant
# Kinetic coefficient mu between phases 2 and 2 [ min. value ] [cm**4/(Js)] ?
1.00000E-05
# Shall misorientation be considered?
# Options: misorientation no_misorientation [transition LAB/HAB in degree]
no_misorientation
#
#
# Concentration data
# ==================
# Number of dissolved constituents? (int)
2
# Type of concentration?
# Options: atom_percent (at%)
# weight_percent (wt%)
weight_percent
#
#
# Diffusion Data
# --------------
# ["Terse Mode": Each line starts with component number and phase number]
# Options: diagonal [x] multi [y(1..k)]
# x: one of the characters "n", "d", "i", "I", or "f"
# y: concatenation of "n", "d" or "f" (for each component)
# default: "d" resp. "dddd..."
# Rem: "n":no diffusion, "d": input, "f": T-dep. from file
# "i":infinite, "I": infinite in each grain
# Extra option [+b] for grain-boundary diffusion
# Extra line option (prefactor on time step): cushion <0-1>
# Extra line option: infinite_limit [cm**2/s]
# Finish input of diffusion data with 'end_diffusion_data'.
#
# How shall diffusion of component 1 in phase 0 be solved?
diagonal n
# How shall diffusion of component 1 in phase 1 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.23400
# Activation energy? (real) [J/mol]
1.47700E+05
# How shall diffusion of component 1 in phase 2 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.12300
# Activation energy? (real) [J/mol]
98290.
# How shall diffusion of component 2 in phase 0 be solved?
diagonal n
# How shall diffusion of component 2 in phase 1 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.15900
# Activation energy? (real) [J/mol]
2.61600E+05
# How shall diffusion of component 2 in phase 2 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
127.00
# Activation energy? (real) [J/mol]
2.70800E+05
#
#
# Phase diagram - input data
# ==========================
#
# List of phases and components which are stoichiometric:
# phase and component(s) numbers
# List of concentration limits (at%):
# <Limits>, phase number and component number
# List for ternary extrapolation (2 elements + main comp.):
# <interaction>, component 1, component 2
# Switches: <stoich_enhanced_{on|off}> <solubility_{on|off}>
# End with 'no_more_stoichio' or 'no_stoichio'
no_stoichio
# Is a thermodynamic database to be used?
# Options: database database_verbose no_database
no_database
#
# Input of the phase diagram of phase 1 and phase 2:
# --------------------------------------------------
# Which phase diagram is to be used?
# Options: linear linearTQ
linear
# Temperature of reference point? [K]
1025.00
# Entropy of fusion between phase 1 and 2 ? [J/(cm**3 K)]
0.37
# Input of the concentrations at reference points
# Reference point 1: Concentration of component 1 in phase 1 ? [wt%]
0.10006243
# Reference point 2: Concentration of component 1 in phase 2 ? [wt%]
2.03948576E-03
# Reference point 1: Concentration of component 2 in phase 1 ? [wt%]
3.7999517
# Reference point 2: Concentration of component 2 in phase 2 ? [wt%]
1.5347996
# Input of the slopes at reference points
# Slope m = dT/dC at reference point 1, component 1 ? [K/wt%]
-156.37674
# Slope m = dT/dC at reference point 2, component 1 ? [K/wt%]
-16044.074
# Slope m = dT/dC at reference point 1, component 2 ? [K/wt%]
-22.661476
# Slope m = dT/dC at reference point 2, component 2 ? [K/wt%]
-98.825044
# Please specify the redistribution behaviour of each component:
# Format: forward [backward]
# Options: nple para paratq normal [mob_corr] atc [mob_corr] [verbose]
# Component 1
normal
# Component 2
nple
#
#
# Initial concentrations
# ======================
# How shall initial concentrations be set?
# Options: input equilibrium from_file [phase number]
equilibrium 1
# Initial concentration of component 1 in phase 1 ? [wt%]
0.10000
# Initial concentration of component 2 in phase 1 ? [wt%]
1.5000
#
#
# Parameters for latent heat and 1D temperature field
# ===================================================
# Simulate release of latent heat?
# Options: lat_heat lat_heat_3d[matrix phase] no_lat_heat no_lat_heat_dsc
no_lat_heat
#
#
# Boundary conditions
# ===================
# Type of temperature trend?
# Options: linear linear_from_file profiles_from_file
linear
# Number of connecting points? (integer)
0
# Initial temperature at the bottom? (real) [K]
1023.000
# Temperature gradient in z-direction? [K/cm]
0.0000
# Cooling rate? [K/s]
0.0000
# Moving-frame system in z-direction?
# Options: moving_frame no_moving_frame
no_moving_frame
#
# Boundary conditions for phase field in each direction
# Options: i (insulation) s (symmetric) p (periodic/wrap-around)
# g (gradient) f (fixed) w (wetting)
# Sequence: W E (S N, if 3D) B T borders
pppp
#
# Boundary conditions for concentration field in each direction
# Options: i (insulation) s (symmetric) p (periodic/wrap-around) g (gradient) f (fixed)
# Sequence: W E (S N, if 3D) B T borders
pppp
# Unit-cell model symmetric with respect to the x/y diagonal plane?
# Options: unit_cell_symm no_unit_cell_symm
no_unit_cell_symm
#
#
# Other numerical parameters
# ==========================
# Phase minimum?
1.00E-04
# Interface thickness (in cells)?
3.00


Thanks.


Belo

[Bernd]

Dear Belo,

Welcome to the MICRESS forum!

It seems that you took the Gamma_Alpha_dri example as a template and mainly changed the number of initial grains and the way how they are defined, and increased the mesh size from 0.25 µm to 4 µm.
While the first changes are legitimate so far, you cannot just increase grid size and assume that the simulation runs the same way. Grid spacing is an important numerical parameter. One requirement e.g. is that the diffusion profile of carbon has to be properly resolved (i.e. the pile-up profile should be larger than the interface thickness). And, in order to run quickly, the Gamma_Alpha example is already tight in terms of resolution...
This essentially means that you will hardly be able to simulation a domain of this size with the required resolution of 0.25 µm, if you stick to the conditions which have been selected for the Gamma_Alpha_dri example.
However, if your aimed conditions (temperature, initial composition, cooling rate) were different, the requirements for grid resolution could be others and things would be different.

The reason that you do not get nucleation everywhere comes from the fact that in the Gamma_Alpha example the number of nuclei has been restricted to a relatively small number ("maximum number of new nuclei"). You should increase these numbers!

Bernd