Byeong-Joo Lee

Byeong-Joo Lee Micro Monte Carlo Simulation - Literature (from N.M. Hwang) 1. “Texture Evolution by Grain Growth in the System of Anisotropic Grain Boundary Energy” N.M. Hwang, B.-J. Lee and C.H. Han, Scripta Materialia 37, (1997). 2. “Grain Growth Behavior in the System of Anisotropic Grain Boundary Mobility” Nong Moon Hwang, Scripta Materialia 37, (1997). 3. “Formation of Island and Peninsular Grains during Secondary Recrystallization of Fe-3%Si Alloy” S.B. Lee, N.M. Hwang C.H. Hahn, D.Y. Yoon, Scripta Mater. 39, (1998). 4. “Simulation of Effect of Anisotropic Grain Boundary Mobility and Energy on Abnormal Grain Growth”, N.M. Hwang, J. Mater. Sci. vol. 33, (1998). 5. “Abnormal Grain Growth by Solid-State Wetting along Grain Boundary or Triple Junction” N.M. Hwang, S.B. Lee and D.Y. Kim, Scripta Mater. 44, (2001). 6. “Comparison of the advantages conferred by mobility and energy of the grain boundary in inducing abnormal grain growth using Monte Carlo simulations” Dong-Kwon Lee, Byeong-Joo Lee, Kyung-Jun Ko and Nong-Moon Hwang, Mater. Trans. 50, (2009). 7. “Three-dimensional Monte Carlo simulation for the effect of precipitates and sub-boundaries on abnormal grain growth” Chang-Soo Park, Tae-Wook Na, Hyung-Ki Park, Byeong-Joo Lee, Chan-Hee Han and Nong-Moon Hwang, Scripta Mater. 66, (2012).

Byeong-Joo Lee Normal Grain Growth – The Mechanism

Byeong-Joo Lee Interface-Reaction Controlled Growth - Grain growth in polycrystalline solids ▷ Capillary Effect Consider arbitrarily curved surface element · system condition : V α = V β = V = const. T = const. · dF = -S dT - P dV + γdA = - P β dV β - P α dV α + γdA = - (P β - P α ) dV β + equilibrium - (P β - P α ) dV β + γdA = 0 ∴ dA = (r 1 + δr) θ 1 ․ (r 2 + δr) θ 2 - r 1 θ 1 ․ r 2 θ 2 = (r 1 + r 2 ) δr θ 1 θ 2 + (δr) 2 θ 1 θ 2 ≈ (r 1 + r 2 ) δr θ 1 θ 2 dV β 〓 r 1 r 2 θ 1 θ 2 δr

Byeong-Joo Lee Interface-Reaction Controlled Growth - Grain growth in polycrystalline solids ▶ Grain Growth - no composition change & no phase (crystal structure) change - capillary pressure is the only source of driving force · α and β is the same phase · ∴ : normal growth equation ※ Role of Mobility / Role of Anisotropy in Grain boundary Energy 1. "Grain Growth Behavior in the System of Anisotropic Grain Boundary Mobility," Nong Moon Hwang, Scripta Materialia 37, (1997). 2. "Texture Evolution by Grain Growth in the System of Anisotropic Grain Boundary Energy," Nong Moon Hwang, B.-J. Lee and C.H. Han, Scripta Materialia 37, (1997).

Byeong-Joo Lee Abnormal Grain Growth – The Mechanism?

Byeong-Joo Lee A phase Field Simulation, H.K. Kim & B.-J. Lee (2012) Grain Growth as a Parallel Process - Grain growth in polycrystalline solids

Byeong-Joo Lee Monte Carlo – Monte Carlo Integration x y 1

Byeong-Joo Lee Monte Carlo Simulation - General Scheme (Potts Model: Srolovitz)

Byeong-Joo Lee [110]/[100] Tilt Grain Boundary Energy of Aluminum

Byeong-Joo Lee [100] Twist Grain Boundary Energy of Copper

Byeong-Joo Lee Procedure – Initial Grain Structure and GB Energy anisotropy 80×80×80 3-dim grain structure, with 4×4×4 pixel points in each grain Each Grain has its own orientation (0~900 o ) J increases with increasing misorientation up to 15 o and fluctuates within 20% above 15 o Black lines mean high angle GB while white mean low angle (< 15 o ) grain boundary

Byeong-Joo Lee Check of Lattice Pinning and Choice of Initial Structure Initial structure of 65,679 grains

Byeong-Joo Lee Abnormal Grain Growth – Computer Simulation

Byeong-Joo Lee Effect of Anisotropy of Grain Boundary Mobility on Abnormal GG

Byeong-Joo Lee Effect of Anisotropy of Grain Boundary Energy on Abnormal GG

Byeong-Joo Lee Effect of Anisotropic GBE and precipitates on Abnormal GG C.-S. Park et al., Scripta Mater. (2012)

Byeong-Joo Lee Symmetric Twist GBsSymmetrical Tilt GBs Grain Boundary Energy in bcc Fe