some qustions of recrystallisation

ripening phenomena, dislocations, grainboundary topology
sxxxf
Posts: 3
Joined: Thu Apr 25, 2019 5:55 pm
anti_bot: 333

some qustions of recrystallisation

Post by sxxxf » Mon Apr 29, 2019 4:22 am

Dear everyone
I am new to MICRESS,this is my first post here

I want to do recrystallisation with random(The fifth in the examples----ReX_random),then i had got the Initial microstructure using a random method.There are 4 types grains with numbers 5 5 4 5,They have different energies as in the examples.there are 2 types of seeds---interface and region
---as in the examples.Then i run the program. here is my .in file.

#
# Automatic 'Driving File' written out by MICRESS.
#
#
#
# MICRESS binary
# ==============
# version number: 6.200 (Windows)
# compiled: Nov 27 2014
# compiler version: Intel 1400 20140805
# executable architecture: x64
# Thermo-Calc coupling: disabled
# 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):
1000
# Cells in Y-direction (CellsY):
1
# Cells in Z-direction (CellsZ):
1000
# Cell dimension (grid spacing in micrometers):
# (optionally followed by rescaling factor for the output in the form of '3/4')
0.50000
#
# Flags
# -----
# Type of coupling?
# Options: phase concentration temperature temp_cyl_coord
# [stress] [stress_coupled] [flow] [flow_coarse] [dislocation]
phase
# Type of potential?
# Options: double_obstacle multi_obstacle [fd_correction]
double_obstacle fd_correction
#
# 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_ReX500-500/ReX_random426-2-4
# 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]
# Restart data output? ('rest')
# Options: out_restart no_out_restart [wallclock time, h.]
no_out_restart
# Grain number output? ('korn')
# Options: out_grains no_out_grains
out_grains
# Phase number output? ('phas')
# Options: out_phases no_out_phases [no_interfaces]
no_out_phases
# Fraction output? ('frac')
# Options: out_fraction no_out_fraction [phase number]
no_out_fraction
# Average fraction table? ('TabF')
# Options: tab_fractions no_tab_fractions [front_temp] [TabL_steps]
no_tab_fractions
# Interface output? ('intf')
# Options: out_interface no_out_interface [sharp]
no_out_interface
# Driving-force output? ('driv')
# Options: out_driv_force no_out_driv_force
out_driv_force
# Interface mobility output? ('mueS')
# Options: out_mobility no_out_mobility
no_out_mobility
# Curvature output? ('krum')
# Options: out_curvature no_out_curvature
no_out_curvature
# Interface velocity output? ('vel')
# Options: out_velocity no_out_velocity
no_out_velocity
# Should the grain-time file be written out? ('TabK')
# Options: tab_grains no_tab_grains [extra|standard]
tab_grains
# Should the 'von Neumann Mullins' output be written out? ('TabN')
# Options: tab_vnm no_tab_vnm
no_tab_vnm
# Should the 'grain data output' be written out? ('TabGD')
# Options: tab_grain_data no_tab_grain_data
tab_grain_data
# Temperature output? ('temp')
# Options: out_temp no_out_temp
no_out_temp
# Recrystallisation energy output? ('rex')
# Options: out_recrystall no_out_recrystall
out_recrystall
# Recrystallised fraction output? ('TabR')
# Options: tab_recrystall no_tab_recrystall
no_tab_recrystall
# Dislocation density output? ('rhoD')
# Options: out_disloc no_out_disloc
no_out_disloc
# Miller-Indices output? ('mill')
# Options: out_miller no_out_miller
out_miller
# Orientation output? ('orie')
# Options: out_orientation no_out_orientation
out_orientation
# Should the orientation-time file be written? ('TabO')
# Options: tab_orientation no_tab_orientation [rotmat]
no_tab_orientation
# Should monitoring outputs be written out? ('TabL')
# Options: tab_log [simulation time, s] [wallclock time, min] no_tab_log
no_tab_log
#
#
# 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 0.5 5.
linear_step 1.0 10.
linear_step 2.0 20.
linear_step 5.0 60.
end_of_simulation
# Time-step?
# Options: fix ...[s] automatic automatic_limited
automatic
# Coefficient for phase-field criterion 1.00
# Number of steps to adjust profiles of initially sharp interfaces [exclude_inactive]?
30
#
#
# Phase data
# ==========
# Number of distinct solid phases?
1
#
# Data for phase 1:
# -----------------
# Simulation of recrystallisation in phase 1?
# Options: recrystall no_recrystall [verbose|no_verbose]
recrystall
# Which recrystallisation model?
# Options: energy mean_disloc local_disloc [all_interfaces]
energy
# Energy threshold for recrystallisation model? [J/cm**3 or MPa]
2.123E-03
# 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
#
# Orientation
# -----------
# How shall grain orientations be defined?
# Options: angle_2d euler_zxz angle_axis miller_indices quaternion
miller_indices
#
#
# Grain input
# ===========
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
random
# Integer for randomization?
11
# Number of different types of grains?
4
# Number of grains of type 1?
5
# Number of grains of type 2?
5
# Number of grains of type 3?
4
# Number of grains of type 4?
5
# Input for grain type 1
# ----------------------
# Geometry of grain type 1
# Options: round rectangular elliptic
elliptic
# Minimal value of x-coordinates? [micrometers]
-10.0000
# Maximal value of x-coordinates? [micrometers]
510.000
# Minimal value of z-coordinates? [micrometers]
-10.0000
# Maximal value of z-coordinates? [micrometers]
510.000
# Minimal length of axis along x-axis? [micrometers]
360.000
# Maximal length of axis along x-axis? [micrometers]
370.000
# Minimal length of axis along z-axis? [micrometers]
140.000
# Maximal length of axis along z-axis? [micrometers]
150.000
# Should the Voronoi criterion for grains of type 1 be applied?
# Options: voronoi no_voronoi
voronoi
# Phase number for grain type 1? (int)
1
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
6.90000E-02
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
7.60000E-02
# Determination of grain orientations?
# Options: random fix fix_direction
fix
# Miller indices h,k,l or vector in y-direction [3 reals in one line]
+0.000 +0.000 +1.000
# Miller indices u,v,w or vector in z-direction [3 reals in one line]
+1.000 +1.000 +0.000
# Minimal distance between grains (real) [micrometers]?
100.00
# Input for grain type 2
# ----------------------
# Geometry of grain type 2
# Options: round rectangular elliptic
elliptic
# Minimal value of x-coordinates? [micrometers]
-10.0000
# Maximal value of x-coordinates? [micrometers]
510.000
# Minimal value of z-coordinates? [micrometers]
-10.0000
# Maximal value of z-coordinates? [micrometers]
510.000
# Minimal length of axis along x-axis? [micrometers]
360.000
# Maximal length of axis along x-axis? [micrometers]
370.000
# Minimal length of axis along z-axis? [micrometers]
140.000
# Maximal length of axis along z-axis? [micrometers]
150.000
# Should the Voronoi criterion for grains of type 2 be applied?
# Options: voronoi no_voronoi
voronoi
# Phase number for grain type 2? (int)
1
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
7.70000E-02
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
8.80000E-02
# Determination of grain orientations?
# Options: random fix fix_direction
fix
# Miller indices h,k,l or vector in y-direction [3 reals in one line]
+1.000 +1.000 +3.000
# Miller indices u,v,w or vector in z-direction [3 reals in one line]
+1.000 -1.000 +0.000
# Minimal distance between grains (real) [micrometers]?
100.00
# Input for grain type 3
# ----------------------
# Geometry of grain type 3
# Options: round rectangular elliptic
elliptic
# Minimal value of x-coordinates? [micrometers]
-10.0000
# Maximal value of x-coordinates? [micrometers]
510.000
# Minimal value of z-coordinates? [micrometers]
-10.0000
# Maximal value of z-coordinates? [micrometers]
510.000
# Minimal length of axis along x-axis? [micrometers]
360.000
# Maximal length of axis along x-axis? [micrometers]
370.000
# Minimal length of axis along z-axis? [micrometers]
140.000
# Maximal length of axis along z-axis? [micrometers]
150.000
# Should the Voronoi criterion for grains of type 3 be applied?
# Options: voronoi no_voronoi
voronoi
# Phase number for grain type 3? (int)
1
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
8.90000E-02
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
9.40000E-02
# Determination of grain orientations?
# Options: random fix fix_direction
fix_direction
# Global direction to be fixed
# Options: x (-> fixed Miller-indices QRS)
# y (-> fixed Miller-indices HKL)
# z (-> fixed Miller-indices UVW)
y
# Vector in y-direction (Miller-indices HKL) [3 reals in one line]
1.000 -0.407 -0.121
# Minimal distance between grains (real) [micrometers]?
100.00
# Input for grain type 4
# ----------------------
# Geometry of grain type 4
# Options: round rectangular elliptic
elliptic
# Minimal value of x-coordinates? [micrometers]
-10.0000
# Maximal value of x-coordinates? [micrometers]
510.000
# Minimal value of z-coordinates? [micrometers]
-10.0000
# Maximal value of z-coordinates? [micrometers]
510.000
# Minimal length of axis along x-axis? [micrometers]
360.000
# Maximal length of axis along x-axis? [micrometers]
370.000
# Minimal length of axis along z-axis? [micrometers]
140.000
# Maximal length of axis along z-axis? [micrometers]
150.000
# Should the Voronoi criterion for grains of type 4 be applied?
# Options: voronoi no_voronoi
voronoi
# Phase number for grain type 4? (int)
1
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
9.50000E-02
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
0.14000
# Determination of grain orientations?
# Options: random fix fix_direction
fix
# Miller indices h,k,l or vector in y-direction [3 reals in one line]
+1.000 +1.000 +0.000
# Miller indices u,v,w or vector in z-direction [3 reals in one line]
+1.000 -1.000 +0.000
# Minimal distance between grains (real) [micrometers]?
100.00
#
#
# 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?
2
#
# Input for seed type 1:
# ----------------------
# 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)]?
1
# Substrate phase [2nd phase in interface]?
# (set to 1 to disable the effect of substrate curvature)
1
# maximum number of new nuclei 1?
400
# Grain radius [micrometers]?
2.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# critical recrystallisation energy [J/cm**3 or MPa]?
6.90000E-02
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
parent_relation
# Minimal value of rotation angle? [Degree]
+0.000
# Maximal value of rotation angle? [Degree]
+15.00
# Referring to which coordinate system shall the rotation axis be defined?
# local (system of the crystal)
# global (system of the workpiece)
global
# Rotation axis? [3 reals in one line]
+0.000 +1.000 +0.000
# Shield effect:
# Shield time [s] [shield phase or group number] ?
20.00
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
25.000
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
0.0000
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
0.0000
# Nucleation range
# min. nucleation temperature for seed type 1 [K]
0.000000
# max. nucleation temperature for seed type 1 [K]
1473.000
# Time between checks for nucleation? [s]
1.50000E-02
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
nucleation_noise
# Factor for random noise?
# (applied as DeltaT -> (1+Factor*(RAND-1/2))*DeltaT)
1.000E-04
#
# Input for seed type 2:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
region
# Minimal value of x-coordinates? [micrometers]
0.0000
# Maximal value of x-coordinates? [micrometers]
500.00
# Minimal value of z-coordinates? [micrometers]
0.0000
# Maximal value of z-coordinates? [micrometers]
500.00
# Phase of new grains (integer) [unresolved|add_to_grain]?
1
# 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 2?
100
# Grain radius [micrometers]?
2.00000
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# critical recrystallisation energy [J/cm**3 or MPa]?
9.50000E-02
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
parent_relation
# Minimal value of rotation angle? [Degree]
+20.00
# Maximal value of rotation angle? [Degree]
+25.00
# Referring to which coordinate system shall the rotation axis be defined?
# local (system of the crystal)
# global (system of the workpiece)
global
# Rotation axis? [3 reals in one line]
+0.000 +1.000 +0.000
# Shield effect:
# Shield time [s] [shield phase or group number] ?
20.00
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
25.000
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
0.0000
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
0.0000
# Nucleation range
# min. nucleation temperature for seed type 2 [K]
0.000000
# max. nucleation temperature for seed type 2 [K]
1473.000
# Time between checks for nucleation? [s]
1.50000E-02
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
nucleation_noise
# Factor for random noise?
# (applied as DeltaT -> (1+Factor*(RAND-1/2))*DeltaT)
1.000E-04
#
# Seed for random-number generator initialisation
# -----------------------------------------------
1
#
# 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]
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]
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]]
5.00000E-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)] ?
0.005
# Shall misorientation be considered?
# Options: misorientation no_misorientation [transition LAB/HAB in degree]
misorientation 15.
# Input of the misorientation coefficients:
# Modification of surface energy for low angle boundaries
# Options: factor Read-Shockley
factor
# prefactor of surface energy:
0.20000
# Modification of the mobility for low angle boundaries
# Options: factor Humphreys [min_reduction + parameters B and N (default: min_red=0. B=5.0 N=4.0)]
factor
# prefactor of the mobility for low angle boundaries
0.10000
#
#
# Phase diagram - input data
# ==========================
#
#
# 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]
1473.000
# 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
ppii
# 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?
5.00E-03
# Interface thickness (in cells)?
4.00
#
#


and here are the pictures of ReX_random_rex.
t=14.png
t=14.png (21.29 KiB) Viewed 2725 times
t=5.png
t=5.png (18.68 KiB) Viewed 2725 times
t=1.png
t=1.png (18.47 KiB) Viewed 2725 times
t=0.png
t=0.png (17.56 KiB) Viewed 2725 times
t=0.5.png
t=0.5.png (19.05 KiB) Viewed 2725 times

In picture t=0,There are two color grain boundaries, red and blue. The nuclei formed on the red grain boundary will not disappear, but it grows very slowly. The nuclei formed on the blue grain boundary and in the region will disappear, and finally only the grain boundary intersection can be nucleated and grown (picture t=14)

What should I do to stop the disappearance of all seeds, or to prevent the formation of red grain boundaries and its nucleation, I can accept pictures without red grain boundaries and nucleation (t=14). Even the seeds in the interface and region will disappear.


My english is a little poor,Excuse me for my poor English.I don't know if I explained my problem clearly. If not, please contact me.

Bernd
Posts: 1250
Joined: Mon Jun 23, 2008 9:29 pm

Re: some qustions of recrystallisation

Post by Bernd » Mon Apr 29, 2019 10:23 am

Dear sxxxf,

Welcome to the MICRESS Forum!

I think, the most relevant difference between your input file and the T037_ReX_random_dri.txt (that is the name in the new 6.4 version...) standard example is that you strongly reduced the recrystallisation energy. This already points to the most probable reason why it behaves differently: For growing properly, the seeds need to overcome the driving force which comes from curvature. This in your case turns out to be totally impossible for bulk nucleation, and is generally somewhat easier at interfaces, especially for the red low-angle boundaries: Here, due to the parent-relation nucleation with angles below 15°, the boundaries between the new seeds and the parent grain will always be low-angle bounadries, and thus the interface energy is reduced by a factor of 0.2 (according to the factor misorientation model). This allows the seeds to grow despite of the low recrystallisation energy.
The lower recrystallisation energies also explain the much slower growth of the 'successful' seeds in your case.

Thus, the solution is either to assume the recrystallisation energies to be higher (like in T037_ReX_random_dri.txt), or you assume the interface energies to be generally smaller. Alternatively, you also could increase the initial radius of the seeds, which would also help to overcome the curvature undercooling.

Bernd

Ferguson

Re: some qustions of recrystallisation

Post by Ferguson » Mon May 13, 2019 3:05 pm

recrystallisation for what kind of material ?stainless steel or ceram?

Admin: Identified as spam

Bernd
Posts: 1250
Joined: Mon Jun 23, 2008 9:29 pm

Re: some qustions of recrystallisation

Post by Bernd » Mon May 13, 2019 5:09 pm

Dear Ferguson,

Welcome to the MICRESS forum!

The T037_ReX_random_dri.txt training example is not focussing on a specific material. It just serves as a template for own work on recrystallisation. Linking to a specific material would require taking the specific material parameters for this material, either from literature or by calibration with experimental data.
Up to now we typically treated metallic materials like steels. To be honest, I personally have no idea whether recrystallisation in ceramics would follow similar rules, i.e. whether the models implemented in MICRESS would be valid - maybe, someone else can answer this question...

Bernd

sxxxf
Posts: 3
Joined: Thu Apr 25, 2019 5:55 pm
anti_bot: 333

Re: some qustions of recrystallisation

Post by sxxxf » Wed Jul 03, 2019 10:23 am

Dear Bernd,
Thank you very much for your reply, it helped me a lot.

sxxxf

Kamran
Posts: 12
Joined: Mon Apr 27, 2020 11:51 pm
anti_bot: 333

Re: some qustions of recrystallisation

Post by Kamran » Fri Apr 09, 2021 3:31 am

Dear Brend
I have a question
in case of REX considering for a single phase full martensitic steel (and using Energy thereshold for REX in phase data description, higher amount for min and max REX energy in input grain section and considering 0 as max and min of REX energy plus critical energy for REX as energy threshold in the section of seed description) I can see recrystallization in all of grains...
I want to leave some grains as non-REX ones
what should I do? maybe introduce local_dislocations...right?
as I have martensitic lathes in the shape of elliptical grains and willing to have a combination of REX and non REX grains in designed fraction....
so what is your opinion about the term of fix direction in this command?
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
ix_direction
could it be useful?

Bernd
Posts: 1250
Joined: Mon Jun 23, 2008 9:29 pm

Re: some qustions of recrystallisation

Post by Bernd » Fri Apr 09, 2021 6:35 pm

Hi Kamran,

I am not sure whether I understand the idea behind your setup. Typically, if you have several grains of the same phase, the stored energy in each grain will be different. This allows you selecting those grains where recrystallization can start by a using a critical stored energy for nucleation.
However, the new recrystallized grains probably will not only grow inside those grains where they nucleate, but also (even if more slowly) even into those with a value of the stored energy which is less than the critical one for nucleation.
I can imagine three reasons why you should nevertheless get an only partly recrystallized microstructure:

1.) The process is stopped before complete recrystallisation is reached (e.g. by cooling to room temperature), leaving preferentially those grains unrecrystallized which have a lower stored energy.

2.) There is an effect of misorientation which does not allow recrystallized grains to enter into grains with too much different orientation (i.e. high angle grain boundaries have a lower interface mobility). This you can achieve by using the misorientation models in MICRESS.

3.) There may be pinning by particles which would create a threshold reX-energy needed for growth.

I am unsure how your proposal of fixed orientations enter into these considerations. Please keep in mind that orientation and shape are not linked in any way.
Furthermore, I have no knowledge about specialities of martensite behaviour with respect to recrystallisation...

Bernd

Kamran
Posts: 12
Joined: Mon Apr 27, 2020 11:51 pm
anti_bot: 333

Re: some qustions of recrystallisation

Post by Kamran » Fri Apr 09, 2021 9:15 pm

Dear Brend
thank you for your prompt reply
maybe I should clarify my work at first:
actually, I want to simulate flash annealing at 100K/s heating rate. so, I have single phase cold rolled martensitic microstructure, I have consider martensite as supper saturated ferrite with elliptical shape in grain nucleation, my defined grain size should be small enough as our experimental work, I mean 0.5 in X direction and 0.1 in Z direction, so I should select grid and spacing as follow:

# Geometry
# --------
# Grid size?
# (for 2D calculations: CellsY=1, for 1D calculations: CellsX=1, CellsY=1)
# Cells in X-direction (CellsX):
500
# Cells in Y-direction (CellsY):
1
# Cells in Z-direction (CellsZ):
500
# Cell dimension (grid spacing in micrometers):
# (optionally followed by rescaling factor for the output in the form of '3/4')
0.002

I know it is too fine to define, I should tackle it as actual work, so I have select interface thk as 3 cells
on the other hand, I defined phase 1 and its REX situation as follow:


# Data for phase 1:
# -----------------
# Simulation of recrystallisation in phase 1?
# Options: recrystall no_recrystall [verbose|no_verbose]
recrystall
# Which recrystallisation model?
# Options: energy mean_disloc local_disloc [all_interfaces]
energy
# Energy threshold for recrystallisation model? [J/cm**3 or MPa]
12
# Is phase 1 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
antifaceted
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Number of type of facets in phase 1
1
# kin. anisotropy parameter Kappa?
# only one value for all facets/phases
# 0 < kappa <= 1
0.5
# Number of possible orientations of a facet 1
2
# 1 -th normal vector facet 1 ? 3*
1.0
0.0
1.0
# 2 -th normal vector facet 1 ? 3*
1.0
0.0
-1.0
# Should grains of phase 1 be reduced to categories?
# Options: categorize no_categorize
no_categorize
.
.
.
# Grain input
# ===========
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
random
# Integer for randomization?
5
# Number of different types of grains?
1
# Number of grains of type 1?
1600
# ----------------------
# Geometry of grain type 1
# Options: round rectangular elliptic round_inverse
elliptic
# Minimal value of x-coordinates? [micrometers]
-0.2
# Maximal value of x-coordinates? [micrometers]
1.2
# Minimal value of z-coordinates? [micrometers]
-0.2
# Maximal value of z-coordinates? [micrometers]
1.2
# Minimal length of axis along x-axis? [micrometers]
0.5
# Maximal length of axis along x-axis? [micrometers]
0.55
# Minimal length of axis along z-axis? [micrometers]
0.1
# Maximal length of axis along z-axis? [micrometers]
0.12
# Should the Voronoi criterion be applied?
# Options: voronoi no_voronoi
voronoi
# Phase number? (integer)
#Phase number for grain type 1?
1
#Min and Max for REX energy?
1000
50000
#grain orientation?
fix
0. 1. 0.
0. 0. 1.
#Minimal distance between grains?
0.01
.
.
.
# Input for seed type 1:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple [restrictive]
interface
# Phase of new grains (integer) [unresolved|add_to_grain]?
1 add_to_grain
parent_grain
# 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?
-1
# Grain radius [micrometers]?
0.
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# critical recrystallisation energy [J/cm**3 or MPa]?
12
# Determination of nuclei orientations?
# Options: random fix fix_direction parent_relation
parent_relation
# Minimal value of rotation angle? [Degree]
-0.000
# Maximal value of rotation angle? [Degree]
+0.000
local
0. 1. 0.
# Shield effect:
# Shield time [s] [shield phase or group number] ?
0.
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
1.
# Input of minimal and maximal energy of the nuclei:
# Minimum of recrystallisation energy? [J/cm**3 or MPa]
12.0000
# Maximum of recrystallisation energy? [J/cm**3 or MPa]
50000.0000
# Nucleation range
# min. nucleation temperature for seed type 1 [K]
900
# max. nucleation temperature for seed type 1 [K]
3000.000
# Time between checks for nucleation? [s]
constant
0.1
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
.
.
.
in the Table R we have 5 classifications for grains from min energy to max energy as follow:
# Class 1: from 12.000 (included) to 10010. (excluded) [J/cm**3 or MPa]
# Class 2: from 10010. (included) to 20007. (excluded) [J/cm**3 or MPa]
# Class 3: from 20007. (included) to 30005. (excluded) [J/cm**3 or MPa]
# Class 4: from 30005. (included) to 40002. (excluded) [J/cm**3 or MPa]
# Class 5: from 40002. (included) to 50000. (excluded) [J/cm**3 or MPa]
.
.
.
as you know in flash heating there is coincide between REX and austenite reversion, so
1) I need to have some of first martensite grains as non-REX elliptical shape, I want to leave some grains as non-REX and only willing to have partially REX grains
I changed min and max energy also energy threshold for REX to affect on microstructure and have partial REX, but always all of grains recrystallized simultaneously,
2) on the other hand, in contrary with very fine austenite grain size as 0.005 or even 0.00 in other simulation, I have very very fast austenite growth
I am sure about my interface energy or mobility, otherwise it affect by heating rate
could yo please provide me some information to have it?
Attachments
GammaAlphaPearlite_TQ_korn_mcr2.png
GammaAlphaPearlite_TQ_korn_mcr2.png (66.42 KiB) Viewed 697 times
GammaAlphaPearlite_TQ_korn_mcr1.png
GammaAlphaPearlite_TQ_korn_mcr1.png (78.51 KiB) Viewed 697 times
GammaAlphaPearlite_TQ_korn_mcr.png
GammaAlphaPearlite_TQ_korn_mcr.png (98.19 KiB) Viewed 697 times

Bernd
Posts: 1250
Joined: Mon Jun 23, 2008 9:29 pm

Re: some qustions of recrystallisation

Post by Bernd » Sun Apr 11, 2021 7:54 pm

Dear Kamran,

To be honest, the information you provide confuses me! You say, recrystallisation of martensite is always connected with transformation to austenite. This means that we don't speak about normal recrystallisation but about a phase transformation. However, the data for initial grains and nucleation you show don't include a second phase (=austenite). Furthermore, the nucleation type you show does not present nucleation of recrystallized grains but only a redefinition of the reX-energy to the threshold value of 12 J/cm3 - or am I overlooking something?

Bernd

Kamran
Posts: 12
Joined: Mon Apr 27, 2020 11:51 pm
anti_bot: 333

Re: some qustions of recrystallisation

Post by Kamran » Sun Apr 11, 2021 8:14 pm

Dear Brend
my work is phase transformation through austenite reversion from an initial full martensitic microstructue in the flash heating...
by applying flash heating around 100 K/s we have overlap between post started recrystallization and austenite reversion (which can form above Ac1)
it is nature of rapid heating, because can postpone the recrystallization start temp.
so, I need to know how can I define input data to have partially REX grains+some grains totally non-REX+austenite reversion?
I know before about austenite reversion during this flash annealing, so I need to define data to have other ones in the field of recrystallization.
yes, by changing energy for REX and min or max or threshold or critical values for that I have redefinition for that and happening of REX just for all grains which is not my desired objective.
using other ways, like local dislocation model needs further calculation with other software to define as input data, so I would rather to know about how can I define current model for energy base grains to have partially REX and non REX grains?
your further suggestion and advices are totally welcome

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