Re: Interfacial energy, morphology and triple junction angle
Posted: Sun Feb 12, 2017 2:10 am
Dear Bernd,
Thanks again for your help!
I am still struggling to get the needle shape. I have been changing parameters, but many things are still unclear to me. I´ve read the manual and also looked for answers here in the forum, but I still do not fully undertand some behaviors. Therefore, I would highly appreciate if you could clafify the following points:
1) In the nucleation subroutine, when I set the min. and max. orientation angle of ferrite to a certain value (say, x), my .ori file shows an orientation of (90+y+x), where y is the rotation angle that I set to my gamma grain 1. In the attached file, for instance, I set x= y=40 expecting them to have a parent relation = 0, but eventually the phase 2 got an orientation= 80. I also tryed to set x=-35 and y=5 and in this case my .ori file showed orientation = 60 to phase 2 (90+5-35). Why does it happen? The code will always make this operation? Why is grain 1 rotation taken into account and not grain 2?
2) To try to fix the abovementioned "problem", I then, set the rotation of gamma grain 1 = 5, rotation of gamma grain 2= 40, max and min rotation of alpha = -90 and misorientation between low and high angle = 15. This way, I got the same orientation of ferrite and gamma grain 1 (5°), and a high misorientation between ferrite and gamma grain 2. Since I used antifaceted and parent relation, I was expecting to get the needle shape towards grain 2, but I couldn´t get this shape. The behavior I got was ferrite "round" grains growing only towards grain 2 (higher misorientation). Why the antifaceted model is not working in this case? How can I fix this problem?
Please, find below part of my input file. It there something wrong in the parameters preventing me to get the ferrite grains to grow as needles only into grain 2?
3) How can I make the needle grow in an "angular" direction? I tried to change the facet vector, but I no longer got the needle shape.
# 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
antifaceted
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Number of type of facets in phase 2
1
# kin. anisotropy parameter Kappa?
# only one value for all facets/phases
# 0 < kappa <= 1
0.3000000
# Number of possible orientations of a facet 1
1
# 1 -th normal vector facet 1 ? 3*
1.000000
0.000000
0.000000
....
# Grain input
# ===========
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
deterministic
# NB: the origin of coordinate system is the bottom left-hand corner,
# all points within the simulation domain having positive coordinates.
# Number of grains at the beginning?
2
# Input data for grain number 1:
# Geometry?
# Options: round rectangular elliptic
round
# Center x,z coordinates [micrometers], grain number 1?
0.00000
31.0000
# Grain radius? [micrometers]
45.0000
# Shall grain 1 be stabilized or shall
# an analytical curvature description be applied?
# Options: stabilisation analytical_curvature
stabilisation
# Should the Voronoi criterion?
# Options: voronoi no_voronoi
voronoi
# Phase number? (integer)
1
# Rotation angle? [Degree]
5.00000000000000
# Input data for grain number 2:
# Geometry?
# Options: round rectangular elliptic
round
# Center x,z coordinates [micrometers], grain number 2?
62.0000
31.0000
# Grain radius? [micrometers]
45.0000
# Shall grain 2 be stabilized or shall
# an analytical curvature description be applied?
# Options: stabilisation analytical_curvature
stabilisation
# Should the Voronoi criterion?
# Options: voronoi no_voronoi
voronoi
# Phase number? (integer)
1
# Rotation angle? [Degree]
40.0000000000000
....
# 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]?
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 1?
50
# 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 randomZ fix range parent_relation
parent_relation
# Minimal value of rotation angle? [Degree]
-90.00
# Maximal value of rotation angle? [Degree]
-90.00
....
# 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]]
2.0E-5
# 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)] ?
1.10000E-05
# 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
Read-Shockley
# 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)]
Humphreys
# Is interaction isotropic?
# Optionen: isotropic anisotropic
anisotropic
# This anisotropic interaction is not yet implemented.
# Instead: isotropic-faceted
# static anisotropy coefficient of facet 1 (0 < a <= 1, 1=isotrop, 0 not defined)
0.15
# kinetic anisotropy coefficient of facet 1 (0 <= a <= 1, 1=isotrop)
0.195
Looking forward to hearing back from you.
Thank you so much!
Thanks again for your help!
I am still struggling to get the needle shape. I have been changing parameters, but many things are still unclear to me. I´ve read the manual and also looked for answers here in the forum, but I still do not fully undertand some behaviors. Therefore, I would highly appreciate if you could clafify the following points:
1) In the nucleation subroutine, when I set the min. and max. orientation angle of ferrite to a certain value (say, x), my .ori file shows an orientation of (90+y+x), where y is the rotation angle that I set to my gamma grain 1. In the attached file, for instance, I set x= y=40 expecting them to have a parent relation = 0, but eventually the phase 2 got an orientation= 80. I also tryed to set x=-35 and y=5 and in this case my .ori file showed orientation = 60 to phase 2 (90+5-35). Why does it happen? The code will always make this operation? Why is grain 1 rotation taken into account and not grain 2?
2) To try to fix the abovementioned "problem", I then, set the rotation of gamma grain 1 = 5, rotation of gamma grain 2= 40, max and min rotation of alpha = -90 and misorientation between low and high angle = 15. This way, I got the same orientation of ferrite and gamma grain 1 (5°), and a high misorientation between ferrite and gamma grain 2. Since I used antifaceted and parent relation, I was expecting to get the needle shape towards grain 2, but I couldn´t get this shape. The behavior I got was ferrite "round" grains growing only towards grain 2 (higher misorientation). Why the antifaceted model is not working in this case? How can I fix this problem?
Please, find below part of my input file. It there something wrong in the parameters preventing me to get the ferrite grains to grow as needles only into grain 2?
3) How can I make the needle grow in an "angular" direction? I tried to change the facet vector, but I no longer got the needle shape.
# 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
antifaceted
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Number of type of facets in phase 2
1
# kin. anisotropy parameter Kappa?
# only one value for all facets/phases
# 0 < kappa <= 1
0.3000000
# Number of possible orientations of a facet 1
1
# 1 -th normal vector facet 1 ? 3*
1.000000
0.000000
0.000000
....
# Grain input
# ===========
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
deterministic
# NB: the origin of coordinate system is the bottom left-hand corner,
# all points within the simulation domain having positive coordinates.
# Number of grains at the beginning?
2
# Input data for grain number 1:
# Geometry?
# Options: round rectangular elliptic
round
# Center x,z coordinates [micrometers], grain number 1?
0.00000
31.0000
# Grain radius? [micrometers]
45.0000
# Shall grain 1 be stabilized or shall
# an analytical curvature description be applied?
# Options: stabilisation analytical_curvature
stabilisation
# Should the Voronoi criterion?
# Options: voronoi no_voronoi
voronoi
# Phase number? (integer)
1
# Rotation angle? [Degree]
5.00000000000000
# Input data for grain number 2:
# Geometry?
# Options: round rectangular elliptic
round
# Center x,z coordinates [micrometers], grain number 2?
62.0000
31.0000
# Grain radius? [micrometers]
45.0000
# Shall grain 2 be stabilized or shall
# an analytical curvature description be applied?
# Options: stabilisation analytical_curvature
stabilisation
# Should the Voronoi criterion?
# Options: voronoi no_voronoi
voronoi
# Phase number? (integer)
1
# Rotation angle? [Degree]
40.0000000000000
....
# 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]?
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 1?
50
# 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 randomZ fix range parent_relation
parent_relation
# Minimal value of rotation angle? [Degree]
-90.00
# Maximal value of rotation angle? [Degree]
-90.00
....
# 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]]
2.0E-5
# 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)] ?
1.10000E-05
# 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
Read-Shockley
# 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)]
Humphreys
# Is interaction isotropic?
# Optionen: isotropic anisotropic
anisotropic
# This anisotropic interaction is not yet implemented.
# Instead: isotropic-faceted
# static anisotropy coefficient of facet 1 (0 < a <= 1, 1=isotrop, 0 not defined)
0.15
# kinetic anisotropy coefficient of facet 1 (0 <= a <= 1, 1=isotrop)
0.195
Looking forward to hearing back from you.
Thank you so much!