Publications

S. J. Jung, S. S. Sohn, D. H. Lee, W.-S. Ko, T. J. Ha, R.-H. Kwak, B.-C. Suh*, Y. M. Kim*, H.-K. Park*, Effect of Ni content on the microstructure and hydrogen storage properties of hyper-eutectic Mg-Ni alloys, Submitted.

Y. Park, S. Choi, K. Ryou, J. Park, W. S. Choi, W.-S. Ko, P.-P. Choi, G.-D. Sim*, Effect of compositional undulation on the mechanical behavior of atomic-scale planar-faulted Ni-Mo-W films, Submitted.

Y. Oh, S. Sung, J.-I. Jang, W.-S. Ko*, H. N. Han*, Integrated experimental and computational study on the role of hydrogen in mechanical responses of pure tungsten, Submitted.

H. J. Bae, J. E. Jung, W.-S. Ko, J. B. Jeon, J.-H. Jang, W. H. Jo, C. H. Lee, J. W. Bae, J.-S. Lee, H.-U. Hong, H. Sung, H. S. Kim, Y.-K. Lee, J. B. Seol*, Direct observation of twinning complexions and their impact on high-temperature Ni base alloys, Submitted.

R. N. Hajra, B. J. Han, J. W. Park, J. Lee, W.-S. Ko, J. H. Kim*, In-situ Experimental and First-Principles Calculations Study of Sigma (σ) Phase Evolution in Duplex Stainless Steel: Unraveling Critical Findings, Submitted.

K. Jang, W.-S. Ko, J.-H. Son, J.-I. Jang, B. Kim, M. Vega-Parades, H. Jang, M. Allahyari, S.-H. Kim, K. H. Ryou, D. Chae, H. Park, Y. S. Jung, M.-W. Oh, C. Jung*, C. Scheu*, P.-P. Choi*, Impact of hierarchical dopant-induced microstructure on thermoelectric properties of p-type Si-Ge alloys revealed by comprehensive multi-scale characterization, Advanced Functional Materials (2024) 2403785.

W.-S. Ko*, J. Hur, J.-Y. Hwang, Y.-B. Chun*, Atomistic investigation of phase transformations in NiTiCu shape memory alloys, International Journal of Mechanical Sciences 274 (2024) 109256.

S. Nam, H. Son, Y. Song, J. Han, W.-S. Ko, S. S. Sohn, H. S. Kim,  H. Choi*, Activation of deformation twinning in ultrafine-grained high-entropy alloys via tailoring stacking fault energy and critical twinning stress, Materials Science and Engineering: A 897 (2024) 146055.

W.-S. Ko*, M.-S. Yoon, J. Hur, R.-H. Kwak, T.-W. Na, H.-K. Park*, Density functional theory study on the role of ternary alloying elements in TiMn2-based hydrogen storage alloys, International Journal of Hydrogen Energy 63 (2024) 151-162.

H. G. Kwon, S. Jung, W.-S. Ko, R.-H. Kwag, D. H. Lee, T.-W. Na, S. Kim*, S. Park*, H.-K. Park*, Microstructural study on the slope of plateau pressure in TiFe0.8Al0.2 hydrogen storage alloy, Materials Letters 360 (2024) 135951.

J. S. Lee, G. Xu, J. S. Suh, J. H. Bae, B.-C. Suh*, Y. M. Kim*, W.-S. Ko*, B.-J. Lee, Atomistic investigation into the formation of axial weak twins during compression of single crystal Mg nanopillars, Acta Materialia 263 (2024) 119512.

S.-M. Park, D. H. Kim, T.-S. Jun, H.-T. Im, N.-S. Kim, W.-S. Ko, C.-S. Park, K. Park*, D. H. Kim*, H.-K. Park*, The effect of V/C ratio on the phase formation behavior in VC based tool steel fabricated through powder metallurgy, Steel Research International (2024) 2300514.

H. G. Kwon, K. B. Park, J. O. Fadonougbo, R.-H. Kwak, D. H. Lee, C.-S. Park, Y. D. Kim*, W.-S. Ko*, H.-K. Park*, Study on the microstructure and hydrogen storage property changes of cast TiFe0.9Cr0.1 alloy by homogenization annealing, Materials Chemistry and Physics 309 (2023) 128362.

G.-S. Ham, Y.-H. Cho, S.-Y. Park, C. P. Kim, W.-S. Ko, G. A. Lee*, Fabrication, microstructure, and wear properties of novel Fe-Cr-B-Nb-Mo metamorphic alloy coatings manufactured by the HVOF thermal spray process, Intermetallics 162 (2023) 108038.

D. H. Kim, J.-Y. Park, S. J. Hong, H.-T. Im, W.-S. Ko, K. B. Park, H. G. Kwon, C. B. Mo*, H.-K. Park*, Correlation between cooling rate and γ' precipitate size in Rene 95 alloy fabricated through a powder metallurgy process, JOM 75 (2023) 2489.

W. H. Ryu*, W.-S. Ko, H. Isano,  R. Yamada, H. Ahn, G. H. Yoo, K. N. Yoon, E. S. Park*, J. Saida, Sustainable steady-state serrated flow induced by modulating deformation sequence in bulk metallic glass, Journal of Alloys and Compounds 946 (2023) 169308.

H. Chung+, W. S. Choi+, H. Jun, H.-S. Do, B.-J. Lee, P.-P. Choi, H. N. Han, W.-S. Ko, S. S. Sohn*, Doubled strength and ductility via maraging effect and dynamic precipitate transformation in ultrastrong medium-entropy alloy, Nature Communications 14 (2023) 145.

H. Jung, G. Lee, M. Koo, H. Song, W.-S. Ko, S. S. Sohn*, Effects of Mn segregations on intergranular fracture in a medium-Mn low-density steel, Steel Research International 94 (2023) 2200240.

S. J. Kim, K. N. Yoon, W.-S. Ko, E. S. Park*, Entropy-stabilized silicides: Expanding the B20 single phase region from mono-silicide to high-entropy silicide, APL Materials 10 (2022) 121105.

J. B. Seol+*, W.-S. Ko+, S. S. Sohn, M. Y. Na, H. J. Chang, Y.-U. Heo, J. G. Kim, H. Sung, Z. Li, E. Pereloma, H. S. Kim*, Mechanically derived short-range order and its impact on the multi-principal-element alloys, Nature Communications 13 (2022) 6766.

J. S. Lee, Y.-B. Chun*,  W.-S. Ko*, Molecular Dynamics Simulations of PtTi High-Temperature Shape Memory Alloys Based on a Modified Embedded-Atom Method Interatomic Potential, Materials 15 (2022) 5104.

W.-S. Ko*, E. Y. Yoon*, J. B. Jeon, Y. Lee, Atomistic simulations of AuTi high-temperature shape memory alloys, International Journal of Mechanical Sciences 227 (2022) 107467.

S.-H. Oh, D. Seol, Y.-J. Jeong, S.-H. Na, J. Kim, W.-S. Ko, J. B. Jeon, B.-J. Lee*, Diffusion in A15 Nb3Sn: An atomistic study, Acta Materialia 234 (2022) 118050.

J.O. Fadonougbo, K. B. Park, T.-W. Na, H.-K. Park,* W.-S. Ko*, An integrated computational and experimental method for predicting hydrogen plateau pressures of TiFe1-xMx room temperature hydrides, International Journal of Hydrogen Energy 47 (2022) 17673-17682.

J. S. Lee, W.-S. Ko*, B. Grabowski, Atomistic simulations of the deformation behavior of an Nb nanowire embedded in a NiTi shape memory alloy,  Acta Materialia 228 (2022) 117764.

Y. Wang, K. Gao, X. Tao, W.-S. Ko, J. Wang, F. Chen, G. Xu*, Y. Cui*, Experimental investigation and thermodynamic description of Mg–Sc–Zn ternary system, CALPHAD 77 (2022) 102406.

J.-Y. Park, W.-S. Ko, K. B. Park, G. B. Kang, H.-T. Im, H. G. Kwon, N.-M. Hwang*, H.-K. Park*, Effect of cooling rate on phase transformation behavior during isothermal annealing of SCr420 steel, Steel Research International (2022) 2100711.

V. D. Sartika, W. S. Choi, G. Choi, J. Han, S.-J. Chang, W.-S. Ko, B. Grabowski, and P.-P. Choi, Joining dissimilar metal of Ti and CoCrMo using directed energy deposition, Journal of Materials Science & Technology 111 (2022) 99-110.

Y. Oh, W.-S. Ko, N. Kwak, J.-I. Jang, T. Ohmura, H.N. Han, Small-scale analysis of brittle-to-ductile transition behavior in pure tungsten, Journal of Materials Science & Technology 105 (2022) 242-258.

W.-S. Ko*, J. S. Lee, D.-H. Kim*, Atomistic simulations of Ag-Cu-Sn alloys based on a new modified embedded-atom method interatomic potential, Journal of Materials Research (2022) < Invited for JMR Annual Special Issue: Early Career Scholars 2022>.

K. B. Park, C.-S. Park, J.-H. Lee, T.-W. Na, H.-S. Kang, W.-S. Ko*, H.-K. Park*, Effect of Fe substitution on first hydrogenation kinetics of TiFe-based hydrogen storage alloy after air exposure, International Journal of Hydrogen Energy 46 (2021) 30780-30789.

W.-M. Choi, J.-S. Kim, W.-S. Ko, D. G. Kim, Y. H. Jo, S. S. Sohn, S. Lee, B.-J. Lee*, Computational design of V-CoCrFeMnNi high-entropy alloys: An Atomistic Simulation Study, CALPHAD 74 (2021) 102317.

W.-S. Ko*, K. B. Park, H.-K. Park*, Density functional theory study on the role of ternary alloying elements in TiFe-based hydrogen storage alloys, Journal of Materials Science & Technology 92 (2021) 148-158.

H. J. Im, W. S. Choi, K. Ryou, J. B. Seol, T. H. Kang, W.-S. Ko*, P.-P. Choi*, Enhanced microstructural stability of γ/γ′-strengthened Co-Ti-Mo-based alloys through Al additions, Acta Materialia 214 (2021) 117011.

K. B. Park, W.-S. Ko, J. O. Fadonougbo, T.-W. Na, H.-T. Im, J.-Y. Park, J.-W. Kang, H.-S. Kang, C.-S. Park*, H.-K. Park*, Effect of Fe substitution by Mn and Cr on first hydrogenation kinetics of air-exposed TiFe-based hydrogen storage alloy, Materials Characterization 178 (2021) 111246.

W. S. Choi*, E. L. Pang, W.-S. Ko, H. Jun, H. J. Bong, C. Kirchlechner, D. Raabe, P.-P. Choi*, Orientation -dependent plastic deformation mechanisms and competition with stress-induced phase transformation in microscale NiTi, Acta Materialia 208 (2021) 116731.

W.-S. Ko*, W. S. Choi, G. Xu, P. P. Choi*, Y. Ikeda, B. Grabowski, Dissecting functional degradation in NiTi shape memory alloys containing amorphous regions via atomistic simulations, Acta Materialia 202 (2021) 331-349.

R. Dong, G. Xu*, W.-S. Ko, J. Wang, X. Tao, Y. Cui, Diffusion behaviors and atomic mobilities in Mg–Sc hcp and bcc alloys: Investigation via single-phase and multi-phase diffusion couples, CALPHAD 72 (2021) 102228.

W.-S. Ko*, J. B. Jeon*, Atomistic simulations on orientation dependent martensitic transformation during nanoindentation of NiTi shape-memory, Computational Materials Science 187 (2021) 110127.

J. Jiang, W.-S. Ko, S.-H. Joo, D.X. Wei, T. Wada, H. Kato, D.V. Louzguine-Luzgin, Experimental and molecular dynamics studies of phase transformations during cryogenic thermal cycling in complex TiNi-based crystalline/amorphous alloys, Journal of Alloys and Compounds 854 (2021) 155379.

T. Lee, S.-W. Kim, J. Y. Kim, W.-S. Ko*, S. Ryu*, First-principles study of the ternary effects on the plasticity of γ-TiAl crystals, Scientific Reports 10 (2020) 21614.

Y. Kim, W.-S. Ko, B.-J. Lee*, Second nearest-neighbor modified embedded atom method interatomic potentials for the Na unary and Na-Sn binary systems, Computational Materials Science 185 (2020) 109953.

H. J. Im, S. Lee, W. S. Choi, S. K. M., D. Raabe, W.-S. Ko*, P.-P. Choi*, Effects of Mo on the mechanical behavior of γ/γʹ-strengthened Co-Ti-based alloys, Acta Materialia 197 (2020) 69-80.

W.-S. Ko*, A. Stukowski, R. Hadian, A. Nematollahi, J. B. Jeon, W. S. Choi, G. Dehm, J. Neugebauer, C. Kirchlechner, B. Grabowski, Atomistic deformation behavior of single and twin crystalline Cu nanopillars with preexisting dislocations, Acta Materialia 197 (2020) 54-68.

J. B. Seol*, J. W. Bae, J. G. Kim, H. Sung, Z. Li*, H. H. Lee, S. H. Shim, J. H. Jang, W.-S. Ko, S. I. Hong, H. S. Kim*, Short-range order strengthening in boron-doped high-entropy alloys for cryogenic applications, Acta Materialia 194 (2020) 366-377.

G.-W. Park, H. Jo, M. Park, S. Shin, W.-S. Ko, N. Park, B.-J. Kim, Y.-S. Ahn*, J. B. Jeon*,"Microstructure and mechanical properties of gas tungsten arc welded high manganese steel sheet", Metals 9 (2019) 1167.

Y. Oh, N. Kwak, K. Lee, W.-S. Ko*, H. N. Han*, Ductility enhancement of tungsten after plastic deformation, Journal of Alloys and Compounds 787 (2019) 801-814.

A. Ahadi*, T. Kawasaki, S. Harjo, W.-S. Ko, Q. Sun, K. Tsuchiya, Reversible elastocaloric effect at ultra-low temperatures in nanocrystalline shape memory alloys, Acta Materialia 165 (2019) 109-117.

W.-S. Ko*, D.-H. Kim*, Y.-J. Kwon, M. H. Lee, Atomistic simulations of pure tin based on a new modified embedded-atom method interatomic potential, Metals 8 (2018) 900.

W.-S. Ko*, J. B. Jeon*, "Atomistic simulations of PdTi high-temperature shape-memory alloys", Intermetallics 102 (2018) 46-57.

W.-S. Ko*, "Temperature dependence of NiTi martensite structures: Density functional theory calculations", Scripta Materialia 154 (2018) 134–138.

W.-S. Ko*, B. Grabowski, J. Neugebauer, "Impact of asymmetric martensite and austenite nucleation and growth behavior on the phase stability and hysteresis of freestanding shape-memory nanoparticles", Physical Review Materials <Rapid Communication> 2 (2018) 030601(R).

T.-H. Nam, E. An, B. J. Kim, S. Shin, W.-S. Ko, N. Park, N. Kang*, J. B. Jeon*,"Effect of post weld heat treatment on the microstructure and mechanical properties of a submerged-arc-welded 304 stainless steel", Metals 8 (2018) 26.

S. B. Maisel*, W.-S. Ko,  J.-L. Zhang, B. Grabowski, J. Neugebauer, "Thermomechanical response of NiTi shape-memory nanoprecipitates in TiV alloys", Physical Review Materials 1 (2017) 033610.

W.-S. Ko*, J. B. Jeon*, "Interatomic potential that describes martensitic phase transformations in pure lithium", Computational Materials Science 129 (2017) 202–210.

W.-S. Ko*, S. B. Maisel, B. Grabowski, J. B. Jeon, J. Neugebauer, "Atomic scale processes of phase transformations in nanocrystalline NiTi shape-memory alloys", Acta Materialia 123 (2017) 90-101.

J.-K. Kim*, W.-S. Ko, S. Sandlöbes, M. Heidelmann, B. Grabowski, D. Raabe, "The role of metastable LPSO building block clusters in phase transformations of an Mg-Y-Zn alloy", Acta Materialia 112 (2016) 171-183.

J.-Y. Oh, W.-S. Ko, J.-Y. Suh, Y.-S. Lee, B.-J. Lee, W. Y. Yoon, S.-H. Shim* "Enhanced high temperature hydrogen permeation characteristics of V-Ni alloy membranes containing a trace amount of yttrium", Scripta Materialia 116 (2016) 122-126.

W.-S. Ko, J.-H. Shim, W.-S. Jung, B.-J. Lee*, "Computational screening of alloying elements for the development of sustainable V-based hydrogen separation membranes", Journal of Membrane Science 497 (2016) 270-281.

W.-S. Ko*, B. Grabowski, J. Neugebauer, "Development and application of a Ni-Ti interatomic potential with high predictive accuracy of the martensitic phase transition", Physical Review B 92 (2015) 134107.

W.-S. Ko, J.-Y. Oh, J.-H. Shim, J.-Y. Suh, W. Y. Yoon and B.-J. Lee*, "Design of sustainable V-based hydrogen separation membranes based on grain boundary segregation", International Journal of  Hydrogen Energy 39 (2014) 12031-12044.

W.-S. Ko and B.-J. Lee*, "Origin of unrealistic blunting during atomistic fracture simulations based on MEAM potentials", Philosophical Magazine 94 (2014) 1745-1753.

W.-S. Ko and B.-J. Lee*, "Modified embedded-atom method interatomic potentials for pure Y and V-Pd-Y ternary system", Modelling and Simulation in Materials Science and Engineering 21 (2013) 085008.

J.-H. Shim*, W.-S. Ko, J.-Y. Suh, Y.-S. Lee and B.-J. Lee, "Atomistic Simulation of Hydrogen Diffusion at Tilt Grain Boundaries in Vanadium", Metals and Materials International 19 (2013) 1221-1225.

W.-S. Ko, J. B. Jeon, C.-H. Lee, J.-K. Lee and B.-J. Lee*, "Intergranular embrittlement of iron by phosphorus segregation: An atomistic simulation", Modelling and Simulation in Materials Science and Engineering 21 (2013) 025012.

J.-H. Shim*, W.-S. Ko, K.-H. Kim, H.-S. Lee, Y.-S. Lee, J.-Y. Suh, Y. W. Cho and B.-J. Lee, "Prediction of hydrogen permeability in V-Al and V-Ni alloy", Journal of Membrane Science 430 (2013) 234-241.

W.-S. Ko, J. Y. Park, J.-Y. Byun, J.-K. Lee, N. J. Kim and B.-J. Lee*, "Manipulation of surface energy anisotropy in iron using surface segregation of phosphorus: An atomistic simulation", Scripta Materialia 68 (2013) 329-332.

W.-S. Ko, J. B. Jeon, J.-H. Shim and B.-J. Lee*, "Origin of hydrogen embrittlement in vanadium-based hydrogen separation membranes", International Journal of Hydrogen Energy 37 (2012) 13583-13593.

W.-P. Dong, H.-K. Kim, W.-S. Ko, B.-M. Lee and B.-J. Lee*, "Atomistic Modeling of pure Co and Co-Al system", CALPHAD 38 (2012) 7-16.

W.-S. Ko, N. J. Kim* and B.-J. Lee*, "Atomistic modeling of an impurity element and a metal-impurity system: pure P and Fe-P system", Journal of Physics: Condensed Matter 24 (2012) 225002.

W.-S. Ko, J.-H. Shim and B.-J. Lee*, "Atomistic Modeling of the Al-H and Ni-H systems", Journal of Materials Research 26 (2011) 1552-1560.

J.-H. Shim*, Y.-S. Lee, E. Fleury, Y. W. Cho, W.-S. Ko, B.-J. Lee, "Modified Embedded-Atom Method Interatomic Potential for the V-H System", CALPHAD 35 (2011) 302-307.

H.-K. Kim, W.-S. Ko, H.-J. Lee, S. G. Kim and B.-J. Lee*, "An identification scheme of grain boundaries and construction of a grain boundary energy database", Scripta Materialia 64 (2011) 1152-1155.

B.-J. Lee*, W.-S. Ko, H.-K. Kim, E.-H. Kim, "The modified embedded-atom method interatomic potentials and recent progress in atomistic simulations", CALPHAD 34 (2010) 510-522.