Article
Physics, Multidisciplinary
Marco Salvalaglio, Axel Voigt, Zhi-Feng Huang, Ken R. Elder
Summary: The study analytically derived the velocity of dislocations to predict effects induced by solute segregation and Cottrell atmospheres in binary systems of various crystalline symmetries. The mesoscopic description of defect dynamics was constructed through the phase-field crystal model, accurately capturing elasticity and plasticity. Modifications of Peach-Koehler force due to solute concentration variations were presented, leading to new predictions of defect motion caused by Cottrell atmospheres.
PHYSICAL REVIEW LETTERS
(2021)
Article
Metallurgy & Metallurgical Engineering
Myriam Dumont, Nikolas Mavrikakis, Wahib Saikaly, Dominique Mangelinck
Summary: In this study, the recrystallization kinetics of Fe-Si-Sn alloys were experimentally studied and a physical model was established to describe the experimental observations. By considering the solute drag effect, the model successfully predicts the evolution of recrystallized fraction and hardness at different temperatures.
METALLURGICAL RESEARCH & TECHNOLOGY
(2023)
Article
Metallurgy & Metallurgical Engineering
Zhen Jiang, Dongfeng Shi, Jin Zhang, Tianming Li, Liwei Lu
Summary: Texture evolution in rolled Mg-1 wt% Zn and Mg-1 wt% Y binary alloys was analyzed using quasi-in situ electron backscatter diffraction (EBSD) during static recrystallization. Mg-1 wt% Zn and Mg-1 wt% Y alloys exhibited strong basal texture at the initial recrystallization state. Zn and Y atoms segregated strongly to the grain boundaries, resulting in different grain boundary migration directions and different outcomes in texture evolution.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Rama Srinivas Varanasi, Baptiste Gault, Dirk Ponge
Summary: This study investigates the influence of molybdenum micro-alloying on medium manganese steel, and explores the mechanism of micro-alloying in the nucleation and growth of austenite, as well as its impact on mechanical properties.
Article
Materials Science, Multidisciplinary
Zonghong Qu, Pingxiang Zhang, Shujin Liang, Yunjin Lai, Jun Wang, Jiangkun Fan, Ruimin Bai
Summary: Flow behavior and dynamic recrystallization of hot isostatically pressed superalloy EP741NP were investigated. Isothermal compression tests were conducted at a moderate strain rate and sub-solvus temperatures, and the deformed samples were analyzed using various microscopy techniques. The results showed that the hot isostatically pressed EP741NP alloy exhibited abnormal flow behavior with four work hardening stages when deformed below 1140 degrees C. This abnormal flow behavior was attributed to the preferential local strain around the previous particle boundary, which interacted with dislocations, stimulating local recrystallization and causing abnormal yielding during work hardening. Subsequently, the dissolved secondary gamma' phases re-precipitated on new gamma grain boundaries, forming a special gamma + gamma' structure that restricted the growth of new gamma grains.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Xuepeng Zhan, Xinmei Liu, Mei Yang, Meng Li, Xifeng Li, Jun Chen
Summary: Friction stir assisted incremental sheet forming has the potential to improve the strength of aluminum alloy sheets by facilitating solute precipitation and generating fine recrystallized grains. The process induces dislocation movements and contributes to the formation of solute precipitates, leading to higher strength and better ductility compared to conventional methods. Additionally, the investigations show that static recrystallization does not occur during FS-ISF.
MATERIALS CHARACTERIZATION
(2021)
Article
Materials Science, Multidisciplinary
Haokai Dong, Yongjie Zhang, Goro Miyamoto, Masahiro Inomoto, Hao Chen, Zhigang Yang, Tadashi Furuhara
Summary: This study quantitatively investigated the amount of Nb segregation, energy dissipation, NbC precipitates, and interface velocity in Fe-0.08C-(0.035, 0.061)Nb model alloys. Results showed that energy dissipation at the migrating interface decreased with longer holding time or higher transformation temperature, and Nb atoms preferred to segregate at the non K-S interface. The occurrence of NbC interphase precipitation indirectly affected transformation kinetics by weakening the SDE via consumption of Nb solutes in ferrite.
Article
Chemistry, Multidisciplinary
Ji-Sang An, Hae-Seung Lee, Pilgyu Byeon, Dongho Kim, Hyung Bin Bae, Si-Young Choi, Jungho Ryu, Sung-Yoon Chung
Summary: When foreign cations are doped into ABO(3)-type perovskite oxides, they usually replace A or B sites depending on their ionic size. This study uncovers the presence of indium dopants occupying square-planar interstices and charge-compensating Ba vacancies at grain boundaries in polycrystalline BaTiO3. This chemical heterogeneity inhibits grain-boundary migration and enables the attainment of fine-grain microstructures with unprecedented dielectric properties.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
I-E Benrabah, H. P. Van Landeghem, F. Bonnet, B. Denand, G. Geandier, A. Deschamps
Summary: The growth kinetics of ferrite during intercritical annealing of steel were investigated using in situ high energy X-ray diffraction. The results showed good agreement between the measured ferrite growth kinetics and the predictions of the solute drag model for different alloy systems. The model successfully predicted ferrite growth kinetics for the quaternary Fe-C-Mn-Cr system using the same interaction values as for ternary Fe-C-Mn and Fe-C-Cr systems.
Article
Materials Science, Multidisciplinary
Xiao-hui Wang, Zhen-bao Liu, Jian-xiong Liang, Zhi-yong Yang, Yong-qing Sun, Chang-jun Wang, Yue Qi
Summary: The static recrystallization behavior of an ultrahigh-strength stainless steel was studied, and it was found that the process was influenced by various factors, with M6C carbides playing a role in suppression. Numerical models were proposed to predict the recrystallized fraction and grain sizes.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Materials Science, Multidisciplinary
Yang Zhao, Jiahao Zheng, Liqing Chen, Xianghua Liu
Summary: The static recrystallization behavior of a low-carbon Nb-V-microalloyed forging steel was investigated in this study. Double-pass hot compression tests were conducted at deformation temperatures of 800-1100 degrees C and interruption times of 1-1000 s. The 2% offset method was used to determine the static recrystallization fractions. The static recrystallization activation energy and the static recrystallization critical temperature were determined. The results showed that the recrystallization fraction curve conformed to the Avrami equation when the deformation temperature was higher than the critical temperature, and a plateau appeared when the temperature was below the critical temperature due to strain-induced precipitation.
Article
Chemistry, Physical
C. Nowak, X. W. Zhou
Summary: The interaction between hydrogen and dislocations has a significant impact on hydrogen embrittlement, but it is not well understood. Previous studies have mainly focused on face-centered-cubic metals rather than body-centered-cubic metals. Molecular dynamics simulations have shown that hydrogen reduces the core energy of dislocations, but its effect on elastic energies and dislocation-dislocation interactions depends on the specific character angle. These findings are important for understanding hydrogen embrittlement and will guide future research in this field.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
G. W. Hu, L. C. Zeng, H. Du, Q. Wang, Z. T. Fan, X. W. Liu
Summary: A novel integrated method combining solute drag and Zenner pinning effects is proposed to control grain growth in NiCoCr medium-entropy alloy, resulting in much finer equiaxed grains. The high growth activation energy obtained shows the effectiveness of this method in tuning the grain growth kinetics during traditional thermomechanical processing.
Article
Materials Science, Multidisciplinary
Ling Zhang, Xiaoyu Wu, Xindong Yang, Yinglong Li
Summary: A study was conducted to investigate the static recrystallization and precipitation behavior of a forged Mg-8.7Gd-4.18Y-0.42Zr alloy annealed at 250-400 degrees Celsius using OM, SEM, TEM, and EBSD methods. The forging process resulted in the formation of coarse grains with parallel and intersecting twins in the microstructure, as well as smaller grains with only parallel twins. During annealing, the presence of twins promoted continuous static recrystallization, with the intersected extension twins being less stable in coarse grains but more conducive to nucleation for recrystallization. Precipitation occurred concurrently with static recrystallization, impeding the growth of the recrystallized grains.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Hyeon-Woo Son, Jae-Cheol Lee, Chang-Hee Cho, Soong-Keun Hyun
Summary: The effect of Mg content on the dynamic recrystallization behavior during hot deformation of Al-Mg alloys was investigated. The results showed that Mg content affected the strain dependence of dislocation parameters, with higher Mg content increasing the dynamic recrystallization rate and inducing flow softening at relatively low strains.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Georg Siroky, Elke Kraker, Dietmar Kieslinger, Ernst Kozeschnik, Werner Ecker
Summary: This research introduces a damage evolution framework with liquid-assisted healing, incorporating factors such as void size, pressure, surface tension, and liquid pressure. Experimental motivation is provided through in-situ melting experiments, illustrating the evolution of void distribution under monotonic tension. The proposed damage formulation focuses on void nucleation and growth, providing insights into void collapse and necessary conditions for healing.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2021)
Article
Metallurgy & Metallurgical Engineering
Yao V. Shan, Mohamed Soliman, Heinz Palkowski, Ernst Kozeschnik
Summary: The study investigates the bake hardening response of a dual-phase steel with a martensite volume fraction of 0.22 through mechanical testing, microstructural characterization, and computational simulation. The kinetics of bake hardening is analyzed based on computational models representing various metallurgical phenomena, and the simulated yield strength evolution is in good agreement with experimental results, showing the effects of temperature, time, and prestrain on the process.
STEEL RESEARCH INTERNATIONAL
(2021)
Article
Metallurgy & Metallurgical Engineering
Philipp Retzl, Walter Mayer, Daniel Krizan, Ernst Kozeschnik
Summary: This study investigates the precipitation of micro-alloying carbo-nitrides in low-carbon TRIP steel during thermo-mechanical treatment, using thermokinetics-based simulation to analyze the influence of the amount, type, and distribution of precipitates in the system. The distribution of carbon among different precipitation domains was found to be the most significant factor governing the evolution of precipitates in the system. Additionally, the simulations demonstrate differences in nucleation and growth behavior between niobium carbide (NbC) and vanadium carbide (VC) precipitates during the thermo-mechanical treatment process.
STEEL RESEARCH INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Georg Siroky, Elke Kraker, Dietmar Kieslinger, Ernst Kozeschnik, Werner Ecker
Summary: The formation of microporosity during solidification of Sn-Bi alloys is investigated through experiments and simulations, with results showing that the round morphology of pores in Sn-20 wt% Bi alloy indicates their formation in the terminal stage of solidification due to volumetric shrinkage in the liquid state of confined eutectic domains.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
J. Svoboda, G. A. Zickler, E. Kozeschnik, F. D. Fischer
Summary: Coarsening of objects, such as grains or precipitates, is a critical process in the heat treatment and high-temperature application of materials. Evolution equations, represented by stationary radius distribution functions, can be used to describe this coarsening process based on appropriate models that incorporate relevant phenomena. The proposed two-parametric family of evolution equations includes the Lifshitz, Slyozov and Wagner (LSW) theory as a special case and allows for the incorporation of specific phenomena controlling object evolution.
Review
Materials Science, Multidisciplinary
Dierk Raabe, Dirk Ponge, Peter J. Uggowitzer, Moritz Roscher, Mario Paolantonio, Chuanlai Liu, Helmut Antrekowitsch, Ernst Kozeschnik, David Seidmann, Baptiste Gault, Frederic De Geuser, Alexis Deschamps, Christopher Hutchinson, Chunhui Liu, Zhiming Li, Philip Prangnell, Joseph Robson, Pratheek Shanthraj, Samad Vakili, Chad Sinclair, Laure Bourgeois, Stefan Pogatscher
Summary: Aluminum has both positive and negative impacts on sustainability. Recycling aluminum can improve sustainability, while extracting it from ores is energy-intensive. The amount of recyclable aluminum is expected to double by 2050, offering an opportunity for a circular economy. However, the presence of elemental contamination in post-consumer scrap poses challenges for alloy design.
PROGRESS IN MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Bernhard Viernstein, Tomasz Wojcik, Ernst Kozeschnik
Summary: A new state parameter-based user-subroutine is presented for finite-element software packages to simulate microstructure-dependent stress-strain relations. Well-established precipitation kinetics, strain hardening, and strengthening models are condensed for computational efficiency while maintaining their predictive capabilities. The framework includes main strengthening mechanisms, and with this novel user-subroutine, the microstructure evolution of various thermo-mechanical treatments on the finite element mesh can be calculated.
Article
Materials Science, Multidisciplinary
Evelyn Sobotka, Johannes Kreyca, Nora Fuchs, Tomasz Wojcik, Ernst Kozeschnik, Erwin Povoden-Karadeniz
Summary: This study investigates the role of titanium and vanadium carbonitrides (Ti,V)(C,N) of the MX series on the austenite-to-ferrite transformation in microalloyed steels and their potential as pre-nuclei for intragranular ferrite nucleation. Experimental and computational simulations are conducted to analyze the phase transition and precipitation sequences within microalloyed steel. The findings provide valuable insights into industrial process optimization without extensive experimental work.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Metallurgy & Metallurgical Engineering
Christoph Etzlstorfer, Alois Leitner, Enno Arenholz, Ernst Kozeschnik
Summary: During heat treatment, element redistribution may occur between the plating materials in cladded steel composites, with carbon diffusion observed between different layers. Numerical simulations with MatCalc software package were conducted to simulate carbon diffusion in roll-cladded steel composites, comparing two material combinations with experimental results. The simulation results showed good agreement with the experimental results, indicating that even short heat treatment intervals can significantly influence carbon redistribution within the steel composite.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Evelyn Sobotka, Johannes Kreyca, Robert Kahlenberg, Aurelie Jacob, Ernst Kozeschnik, Erwin Povoden-Karadeniz
Summary: The recrystallization kinetics and two critical temperatures (T-NR and T-SRCT) of five Nb, Ti, and V microalloyed steel grades are evaluated through experimental examination and thermokinetic computer simulations. The study shows that higher microalloying contents increase both critical temperatures, with Nb having a more pronounced recrystallization retardation effect compared to Ti or V. The employed physics-based simulation approach accurately reproduces the experimental recrystallization behavior of the examined steel grades.
Article
Chemistry, Multidisciplinary
Vasileios Fotopoulos, David Mora-Fonz, Manuel Kleinbichler, Rishi Bodlos, Ernst Kozeschnik, Lorenz Romaner, Alexander L. Shluger
Summary: In this study, computational modeling was used to investigate the structures, formation energies, and migration mechanisms of vacancy clusters in fcc metals. The results showed that di-vacancies have a smaller migration barrier compared to mono-vacancies and other clusters, and this barrier is further reduced at grain boundaries. These findings are important for understanding the structural evolution and diffusion mechanisms of metal films under thermal and mechanical stress.
Article
Engineering, Manufacturing
Abbas Sadeghi, Ernst Kozeschnik, Farid R. Biglari
Summary: Cryogenic rolling is an important severe plastic deformation process to produce high-strength aluminum sheets with excellent formability. This study characterizes the formability of AA6061 before and after cryogenic rolling and artificial aging. The Nakajima method based on ISO standard is used to measure formability. It was found that artificial aging at 150 degrees C is the optimum temperature for achieving a good combination of strength and formability. The strength improved up to 40% during the artificial aging process, with the cryo-rolled sample increasing from 250 MPa to 350 MPa after 50 hours of aging at 150 degrees C. The formability of the cryo-rolled sample was significantly improved, especially for multi-axial forming condition.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
G. Ressel, D. Brandl, T. Honigmann, M. Lukas, A. Stark, C. Gruber, S. Lukas, M. Stockinger, E. Kozeschnik
Summary: This study reports the occurrence of recrystallization without previous deformation in commercial stainless steel 15-5 PH during austenitization. It also reveals the correlation between recrystallization and the mechanisms involved in the prior martensite to austenite transformation.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Robert Kahlenberg, Georg Falkinger, Benjamin Milkereit, Ernst Kozeschnik
Summary: This paper proposes an efficient model for handling heterogeneous nucleation site energy variations and studies their impact on solute nucleation behavior. The model has advantages compared to previous simulations, especially for slow cooling rates.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Manufacturing
Nana Kwabena Adomako, Nima Haghdadi, James F. L. Dingle, Ernst Kozeschnik, Xiaozhou Liao, Simon P. Ringer, Sophie Primig
Summary: Metal additive manufacturing is an ideal technique for producing complex shaped engineering parts, but advanced control of microstructures and properties through modeling is necessary. This study presents a computational modeling approach to predict and optimize the microstructures and properties during metal additive manufacturing.
ADDITIVE MANUFACTURING
(2023)
