Atomistic Simulations for Materials Research
toward a computational materials and process design
Byeong-Joo Lee
Computational Materials Science & Engineering Lab.
Pohang University of Science & Technology
Byeong-Joo Lee
http://cmse.postech.ac.kr
Outline
 Atomistic Simulation
 Grain Boundary Identification Scheme
 Construction of Grain Boundary Energy Database
 Implementation of the DB into Mesoscale Simulations
 Extension into Multicomponent system
 2NN MEAM Interatomic Potential
 Application to Materials and Process Design
 <100> Textured Steels
 Computational Design of Structural Materials
 SiC Single Crystal Growth
 Virtual Lab for Nano Materials
Byeong-Joo Lee
http://cmse.postech.ac.kr
Grain Boundary/Interface Energy
Wetting angle : 36o
Wetting angle : 120o
Fe - 0.5% Mn – 0.1% C, dT/dt = 1 oC/s
from SG Kim, Kunsan University
Byeong-Joo Lee
http://cmse.postech.ac.kr
GBE DB
GB Identification
Multi-scale
Extension
2NN MEAM
Grain Boundary Identification Scheme
x3c
x 2c
x 2c
x 2c
x
x1c
x
x3 ( ND)
x 2 (TD)
c
3
x 2c
x 2c
x 2c
x1c
x3c
x1c
x
c
1
c
3
x
c
3
c
3
x1c
x1c
x
x1 (RD)
How to uniquely define misorientation and inclination between two neighboring grains
Byeong-Joo Lee
http://cmse.postech.ac.kr
GB Identification
GBE DB
Multi-scale
Extension
2NN MEAM
Grain Boundary Energy of BCC Fe
Sigma (Σ)
5
3
11
9
3
7
3
9
7
5
3
5
11
7
9
5
Theta (θ)
36.87
70.53
50.48
38.94
60
38.21
131.81
96.38
73.4
180
180
101.54
62.96
135.58
90
143.13
(hkl) plane
100
110
110
110
111
111
210
210
210
210
211
211
211
211
221
221
Scripta Mater. (2011)
Sigma (Σ)
11
5
7
3
9
11
5
11
7
7
9
9
11
7
5
11
Theta (θ)
144.9
180
115.38
146.44
67.11
180
95.74
100.48
149
180
123.75
152.73
82.16
110.92
154.16
180
(hkl) plane
310
310
310
311
311
311
311
320
320
321
321
322
331
331
331
332
Byeong-Joo Lee
http://cmse.postech.ac.kr
Other crystalline structures
Size of the Euler space necessary to uniquely represent orientations
for various crystal and sample symmetry.
Crystal
structure
Crystal symmetry
Sample
symmetry
Orthotropic
Φ
φ2
Cubic
90°
90°
Tetragonal
90°
90°
Orthorhombic
90°
180°
Hexagonal
90°
60°
Trigonal
90°
120°
Monoclinic
90°
360°
Triclinic
180°
360°
φ1
90°
Byeong-Joo Lee
http://cmse.postech.ac.kr
Conventional Method for Calculation of GB/IFC Energy
σ=
{E(
) – [E(
)+E(
)]}
/ 2A
Mismatch in periodic length
Byeong-Joo Lee
http://cmse.postech.ac.kr
Calculation of Grain Boundary Energy
B.-J. Lee, MSMSE (2004)
Byeong-Joo Lee
http://cmse.postech.ac.kr
Grain Boundary Energy of FCC Fe
Byeong-Joo Lee
http://cmse.postech.ac.kr
Interfacial Energy between BCC & FCC Fe
Byeong-Joo Lee
http://cmse.postech.ac.kr
GB Identification
GBE DB
Multi-scale
Extension
2NN MEAM
Implementation of GBE DB into mesoscale Simulation
Σ3
Σ9
Grain Boundary Energy as a single function
of misorientation and inclination ??
Numerical Method
Byeong-Joo Lee
http://cmse.postech.ac.kr
Test phase field simulation of grain growth
- Isotropic GBE
(2000 steps)
- Sample Size: 200*200*200 grids
- Anisotropic GBE (realistic GBE DB)
(500 steps)
- Isotropic GB mobility
Byeong-Joo Lee
http://cmse.postech.ac.kr
GB Identification
GBE DB
Multi-scale
Extension
2NN MEAM
Effect of Alloying Elements on GB Energy
Byeong-Joo Lee
http://cmse.postech.ac.kr
Effect of Temperature on GB Energy
(110) Symmetric Tilt Boundary Energy of pure Al
Otsuki and Mizuno 1986
calculated at 0 K
measured near melting point
• Introduction of a simple temperature dependence
• GB transition in alloy system and its effect on the GB segregation ??
Byeong-Joo Lee
http://cmse.postech.ac.kr
GB Identification
GBE DB
Multi-scale
Extension
2NN MEAM
2NN MEAM Interatomic Potentials
– History of Development
• EAM Potentials (1983, M.S. Daw and M.I. Baskes)
▷ Successful mainly for FCC elements
- many other many-body potentials show similar performance
• 1NN MEAM Potentials (1987,1992, M.I. Baskes)
▷ Show Possibility for description of various structures
- important to be able to describe multi-component system
• 2NN MEAM Potentials (2000, B.-J. Lee & M.I. Baskes)
▷ Applicable to fcc, bcc, hcp, diamond structures and their alloys
Byeong-Joo Lee
http://cmse.postech.ac.kr
Semi-Empirical Interatomic Potentials – Basic Requirement
• Elastic Constants
▷ B, C11, C12, C44, ...
• Defect Energy
▷ Surface Energy
▷ Heat of Vacancy Formation, …
• Structural Energy
▷ Energy and Lattice Parameters in Different Structures
• Thermal Property
▷ Specific Heat
▷ Thermal Expansion Coefficient
▷ Melting Temperature, ...
Byeong-Joo Lee
http://cmse.postech.ac.kr
2NN MEAM Interatomic Potentials – for pure Elements
Property
C11 (1012 dyne/cm2)
C12 (1012 dyne/cm2)
C44 (1012 dyne/cm2)
Evf (eV)
QD (eV)
EIf (eV)
E(100) (mJ/m2)
E(110) (mJ/m2)
E(111) (mJ/m2)
 d(100) (%)
 d(110) (%)
 d(111) (%)
 Ebcc/fcc (eV/atom)
 Efcc/hcp (eV/atom)
 (0-100oC) (10-6/K)
Cp (0-100oC) (J/mol·K)
m.p. (K)
 H (KJ/mol)
m
 Vm (%)
MEAM-Al (exp.)
1.143 (1.143)
0.619 (0.619)
0.316 (0.316)
0.68 (0.68)
1.33 (1.33)
2.49 (-)
848 (1085a)
948 (1085a)
629 (1085a)
+1.8 (+1.8)
-8.9 (-8.5±1.0)
+1.0 (0.9±0.5)
0.12 (0.10b)
0.03 (0.06b)
22.0 (23.5)
26.2 (24.7)
937 (933)
11.0 (10.7)
6.7 (6.5)
MEAM-Fe (exp.)
2.430 (2.431)
1.380 (1.381)
1.219 (1.219)
1.75 (1.79)
2.28 (2.5)
4.20 (-)
2510 (2360a)
2356 (2360a)
2668 (2360a)
-1.1 (-0.2, -1.5)
-1.5 (0)
-10.5 (-16.9)
0.048 (0.082b)
-0.018 (-0.023b)
12.4 (12.1)
26.1 (25.5)
2000 (1811)
13.2 (13.8)
4.0 (3.5)
Byeong-Joo Lee
http://cmse.postech.ac.kr
Second Nearest Neighbor Modified EAM (2NN MEAM)
Pure Elements
•Fe, Cr, Mo, W, V, Nb, Ta, Li
•Cu, Ag, Au, Ni, Pd, Pt, Al, Pb
•Ti, Zr & Mg
•Mn, P
•C, Si, Ge, In
Phys. Rev. B. 64, 184102 (2001); MSMSE 20, 035005 (2012) .
Phys. Rev. B. 68, 144112 (2003).
Phys. Rev. B. 74, 014101 (2006); CALPHAD 33, 650-57 (2009).
Acta Materialia 57, 474-482 (2009).; J. Phys.: Condensed Matters (2012), in press.
CALPHAD 29, 7-16 (2005); 31, 95-104 (2007); 32, 34-42 (2008); 32, 82-88 (2008)
Multicomponent Systems
•Fe-C, Fe-N, Fe-H
•Fe-Ti & Fe-Nb
•Fe-Ti-C & Fe-Ti-N
•Fe-Nb-C & Fe-Nb-N
•Al-H & Ni-H, V-H
•Fe-Mn
•Fe-Cr
•Fe-Cu
•Fe-Pt
•Fe-Al
•Fe-P
•Al-Ni
•Co-Cu
•Co-Pt
•Cu-Ni
•Ni-W
•Cu-Ti
•Cu-Zr
•Cu-Zr-Ag
•Mg-Al , Mg-Li
•Ga-In-N
Acta Materialia 54, 701-711 (2006); 54, 4597-4607 (2006); 55, 6779-6788 (2007).
Scripta Materialia 59, 595-598 (2008).
Acta Materialia 56 , 3481-3489 (2008); Acta Materialia 57 , 3140-3147 (2009).
J. Materials Research 25, 1288-1297 (2010).
J. Materials Research 26, 1552-1560 (2011); CALPHAD 35, 302-307 (2011).
Acta Materialia 57, 474-482 (2009).
CALPHAD 25, 527-534 (2001).
Phys. Rev. B. 71, 184205 (2005).
J. Materials Research 21, 199-208 (2006).
J. Phys.: Condensed Matters 22, 175702 (2010)
J. Phys.: Condensed Matters (2012), in press.
CALPHAD 31, 53 (2007).
J. Materials Research 17, 925-928 (2002).
Scripta Materialia 45, 495-502 (2001).
CALPHAD 28, 125-132 (2004).
J. Materials Research 18, 1863-1867 (2003).
Mater. Sci. and Eng. A 449-451, 733 (2007).
J. Materials Research 23, 1095 (2008).
Scripta Materialia 61, 801 (2009).
CALPHAD 33, 650-57 (2009); MSMSE 20, 035005 (2012) .
J. Phys.: Condensed Matter 21, 325801 (2009).
Byeong-Joo Lee
http://cmse.postech.ac.kr
<100> textured steels
Structural Materials
SiC Crystal Growth
Virtual Nano Lab.
Development of <100> Textured Steels
Change of Surface Energy Anisotropy due to Surface Segregation
(100)
Bulk
Concentration
1.6%
Surface
Concentration
68%
Ave. Concentration
Surface 3 layers
25%
(110)
1.6%
37%
16%
0.83
(111)
1.6%
78%
27%
0.38
Surface
Surface E, J/m2
0.29
Esurf of pure Fe = 2.50, 2.35, 2.56 for (100), (110), (111)
(100)
0.3%
66%
23%
0.68
(110)
0.3%
35%
14%
1.14
(111)
0.3%
74%
25%
0.78
Surface Segregation
of impurity atoms
on Fe surfaces
Byeong-Joo Lee
http://cmse.postech.ac.kr
Development of <100> Textured Steels
< Surface >
< Bulk >
Phase-Field simulations considering the surface/GB segregation
kinetics of impurity atoms as well as the grain growth is an ongoing research.
Byeong-Joo Lee
http://cmse.postech.ac.kr
<100> textured steels
Structural Materials
SiC Crystal Growth
Virtual Nano Lab.
Multiscale Computational Design of Structural Materials
Byeong-Joo Lee
http://cmse.postech.ac.kr
<100> textured steels
Structural Materials
SiC Crystal Growth
Virtual Nano Lab.
SiC Crystal growth simulation
Effect of
•
•
•
•
•
gas temperature
substrate temperature
deposition rate
vapor composition
doping elements, etc.
on the defect formation
Byeong-Joo Lee
http://cmse.postech.ac.kr
SiC Crystal growth simulation
Effect of process conditions on the resultant crystal structure,
4H vs. 6H
Byeong-Joo Lee
http://cmse.postech.ac.kr
<100> textured steels
Structural Materials
SiC Crystal Growth
Virtual Nano Lab.
Virtual Nano Lab
Byeong-Joo Lee
http://cmse.postech.ac.kr
Virtual Nano Lab
Virtual Lab for Li Ion Battery
Materials
Full Cell Simulation Lab.
Cathode
Design Lab.
•
•
•
•
•
Model construction
Screening
SEI reaction simulation
Structure optimization
Anode Design
Lab.
•
•
•
•
•
Reliability
Test Lab.
• Phase field
simulation
• Tools & method
•
Novel materials design
Intercalation reaction
SEI reaction simulation
Structure optimization
Electrolyte Design Lab.
• Electrolyte Structure Optimization
• Characterization of Electrolyte
•
Byeong-Joo Lee
http://cmse.postech.ac.kr
Summary
 Fundamental materials properties are provided by
atomistic simulations based on interatomic potential
 Macroscale materials properties are obtained from
multiscale simulations
 Multiscale simulation is used for materials and process
design of structural materials
 Atomistic simulation is used for materials and process
design of nano materials, directly or through a virtual
nano fab platform
Byeong-Joo Lee
http://cmse.postech.ac.kr