Article
Materials Science, Multidisciplinary
Chuanlai Liu, Alistair Garner, Huan Zhao, Philip B. Prangnell, Baptiste Gault, Dierk Raabe, Pratheek Shanthraj
Summary: The incorporation of CALPHAD database into a phase-field framework successfully simulated the complex kinetics of non-equilibrium grain boundary microstructures in high-strength Al-Zn-Mg-Cu alloys, which is crucial for understanding the quenching process of the alloys.
Article
Materials Science, Multidisciplinary
Andrey Kuznetsov, Lidia Karkina, Yuri Gornostyrev, Pavel Korzhavyi
Summary: In Al, Zn tends to form a thick segregation layer at grain boundaries, while Mg forms an atomically thin segregation layer. The segregation of Zn decreases the barriers for grain boundary sliding, while the segregation of Mg increases them. These results demonstrate a strong relationship between the chemical bonding of solute atoms, their segregation ability, and grain boundary strength.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
I. Chesser, R. K. Koju, A. Vellore, Y. Mishin
Summary: Atomistic computer simulations are used to investigate the atomic structure, thermal stability, and diffusion processes at the Al-Si interphase boundaries in composite materials. It is found that some stable orientation relationships observed in epitaxy experiments also exist at these interfaces. An interface-induced recrystallization mechanism can transform non-equilibrium interfaces into more stable states. Diffusion of Al and Si atoms in stable Al-Si interfaces is slower compared to diffusion in Al grain boundaries but can be accelerated in the presence of interface disconnections. A qualitative explanation for the sluggish interphase boundary diffusion is proposed, involving correlated atomic rearrangements in the form of strings and rings of collectively moving atoms.
Article
Nanoscience & Nanotechnology
J. Zuo, T. Nakata, C. Xu, Y. P. Xia, H. L. Shi, X. J. Wang, G. Z. Tang, W. M. Gan, E. Maawad, G. H. Fan, S. Kamado, L. Geng
Summary: A high strength dilute Mg-0.8Al-0.1Ca-0.6Mn alloy wire was successfully developed by hot drawing, with the high strength attributed to the ultra-fine DRXed grains, coarse elongated unrecrystallized grains with dense dislocations, and nano sized Al2Ca and Al-Mn precipitates dispersed in the alloy wire.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Shuo Wang, Xiang Cai, Zan Wang, Jia Ju, Jian Zhou, Feng Xue
Summary: This study investigates the impact of solute Al on the penetration of Cu atoms into the Fe grain boundary in the Fe-Cu embrittlement system through molecular dynamics simulations. Additionally, first principle density functional theory calculations are performed to determine the binding properties and electronic structure of GBs doped with solute atoms. The mechanisms of inhibiting liquid metal embrittlement cracks in the Fe-Cu system by Al are analyzed at the atomic scale. The results demonstrate that Al diffusion along the GB direction is much higher than that of Cu, and the preferential penetration and segregation of Al atoms act as a barrier layer.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Zhi Zhang, Jinghuai Zhang, Jinshu Xie, Shujuan Liu, Yuying He, Ru Wang, Daqing Fang, Wei Fu, Yunlei Jiao, Ruizhi Wu
Summary: The addition of trace Sm can significantly increase the grain boundary segregation concentration in the dilute Mg-Zn-Ca-Mn alloy, improve its yield strength, inhibit grain growth during annealing, and contribute to the design of advanced Mg alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Xue-Qi Lv, Xiong-Ying Li, Hong-Bing Liu
Summary: Thermal diffusion plays an important role in determining the structures and properties of interfaces and nanolayers. Different deformation mechanisms apply in Al-Mg-Al nanolayers depending on the thermal diffusion temperature, with the formation of coherent Al/Mg interfaces significantly enhancing the tensile properties at high temperatures.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Chuanlong Xu, Mingyi Zhang, Xiaobao Tian, Wentao Jiang, Qingyuan Wang, Haidong Fan
Summary: The interaction between Mg17Al12 precipitate and low-angle grain boundaries in Mg-Al alloys was investigated using molecular dynamics simulations. The precipitate was found to be sheared by grain boundaries with a rotation angle of 9 degrees or larger, but not sheared with a rotation angle smaller than 8 degrees. An analytical model based on Eshelby theory was proposed to explain this behavior, and it showed good agreement with the simulation results. The critical shear of the grain boundary was found to be related to the aspect ratio of the precipitate.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Anastasia V. Mikhaylovskaya, Olga A. Yakovtseva, Andrey G. Mochugovskiy, Joan Cifre, Igor S. Golovin
Summary: The influence of a minor addition of Zn on the superplastic properties of Al-Mg alloys was investigated. It was found that the addition of a small amount of Zn can promote grain boundary sliding, resulting in increased strain rate sensitivity and elongation-to-failure of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Christopher M. Andolina, Jacob G. Wright, Nishith Das, Wissam A. Saidi
Summary: The addition of Mg to Al materials in Al-Mg alloys can lead to surface segregation and oxidation, resulting in a softer and Al-enriched bulk alloy. Through the use of a robust atomistic deep neural net potential, calculations predict a linear trend in the formation energy and density of Al-Mg alloys with temperature changes.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Wei Zhang, Xuefeng Lu, Junqiang Ren, Junchen Li, Hongtao Xue, Fuling Tang, Xin Guo
Summary: Solute element segregation behavior significantly affects the mechanical properties and deformation mechanism of nanocrystals. By using molecular dynamics, we investigated the effect of segregation structure on the deformation mechanism of NiCoAl nanocrystalline. The results reveal that complete segregation of Al within the grain leads to poor grain boundary stability and ineffective hindrance of dislocation movement, resulting in inferior mechanical properties. However, when 4% of Al transitions to the grain boundary, the stability improves significantly, generating lamination structures that effectively strengthen the nanocrystals.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Alistair Garner, Ryan Euesden, Yichao Yao, Yasser Aboura, Huan Zhao, Jack Donoghue, Michele Curioni, Baptiste Gault, Pratheek Shanthraj, Zak Barrett, Christian Engel, Tim L. Burnett, Phil B. Prangnell
Summary: The size, distribution, and chemical composition of grain boundary-phase precipitates (GBPs) and micro-segregation in two different aluminum alloys have been studied. It was found that the GBPs in AA7050 are larger and more complex, with higher levels of copper and aluminum and lower zinc content compared to AA7085. Limited grain boundary segregation was observed, mainly attributed to differences in the chemical composition of the large Q-GBPs between the two materials.
Article
Materials Science, Multidisciplinary
Jie Feng, Lianpeng Zhang, Yufeng Zhang, Guizhen Feng, Chen Wang, Wenbin Fang
Summary: Multi-pass rolling can improve the strength and ductility synergy in ultrafine-grained AZQ310 alloy sheet by reducing grain boundary segregation. The as-extruded alloy has high yield strength but poor elongation due to the presence of ultra-fine grains and co-segregation of Al/Zn atoms at grain boundaries. In contrast, after multi-pass rolling, the sheet exhibits higher yield and ultimate strength, as well as improved elongation along the rolling direction.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
B. Bian, S. Taheriniya, G. Mohan Muralikrishna, A. Godha, S. K. Makineni, S. Sankaran, B. B. Straumal, Y. Du, G. Wilde, S. V. Divinski
Summary: Kinetic and structural changes induced by Bi alloying in dilute Ni-Bi alloys were investigated, focusing on grain boundary phase transitions. The grain boundary diffusion of Ni in the Ni-Bi alloys was measured across single and two-phase regions of the bulk phase diagram. The results showed that the Ni grain boundary diffusion rates were dependent on the Bi concentration and were influenced by Bi segregation and multi-layer Bi segregation along the grain boundaries. The presence of a liquid layer of Bi at the grain boundaries resulted in the highest Ni diffusivity. Additionally, structural transitions between different grain boundary phases were found to have a significant impact on the grain boundary diffusion rates.
Article
Materials Science, Multidisciplinary
R. K. Koju, K. A. Darling, L. J. Kecskes, Y. Mishin
Article
Materials Science, Multidisciplinary
M. Rajagopalan, K. Darling, S. Turnage, R. K. Koju, B. Hornbuckle, Y. Mishin, K. N. Solanki
MATERIALS & DESIGN
(2017)
Article
Materials Science, Multidisciplinary
R. K. Koju, K. A. Darling, K. N. Solanki, Y. Mishin
Article
Materials Science, Multidisciplinary
M. Rajagopalan, K. A. Darling, C. Kale, S. A. Turnage, R. K. Koju, B. C. Hornbuckle, Y. Mishin, K. N. Solanki
Article
Materials Science, Multidisciplinary
R. K. Koju, Y. Mishin
PHYSICAL REVIEW MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
R. K. Koju, Y. Mishin
Article
Materials Science, Multidisciplinary
C. Kale, S. Srinivasan, B. C. Hornbuckle, R. K. Koju, K. Darling, Y. Mishin, K. N. Solanki
Article
Nanoscience & Nanotechnology
K. A. Darling, S. Srinivasan, R. K. Koju, B. C. Hornbuckle, J. Smeltzer, Y. Mishin, K. N. Solanki
Summary: This study investigates the unexpected refinement of nanograins in a stable nanocrystalline Cu-Ta alloy during severe plastic deformation, where Ta nanoclusters act as kinetic-pinning agents to suppress grain boundary processes during recrystallization, leading to a significant reduction in grain size.
SCRIPTA MATERIALIA
(2021)
Article
Multidisciplinary Sciences
Anuj Bisht, Raj Kiran Koju, Yuanshen Qi, James Hickman, Yuri Mishin, Eugen Rabkin
Summary: The study investigates the effect of alloying on Ni nanoparticles, revealing that alloying can reduce the ultimate strength of the nanoparticles due to solute-induced local spatial variations of the resolved shear stress leading to premature dislocation nucleation. This counter-intuitive solution-softening effect makes the deformation of the particles require more work, increasing their toughness and presenting alloy nanoparticles as promising candidates for applications.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
R. K. Koju, Y. Mishin
Summary: The research reveals that grain boundaries significantly affect solute diffusion, with the formation of grain boundary clusters enhancing solute drag. A 1.5% Ag alloy reduces grain boundary free energy while decreasing grain boundary mobility coefficients.
Article
Materials Science, Multidisciplinary
Amit Sharma, Oz Mendelsohn, Anuj Bisht, Johann Michler, Raj Kiran Koju, Yuri Mishin, Eugen Rabkin
Summary: It is discovered that alloying pristine crystalline nickel nanoparticles with iron leads to unexpected softening due to the random distribution of solute atoms and nano-size precipitates. This softening effect is observed in particles with different compositions and orientations, and it is associated with premature dislocation nucleation caused by the randomly distributed solute atoms. The manipulation of classical hardening mechanisms in defect-free single-crystalline metal nanoparticles offers new possibilities for controlling their plastic deformation.
Article
Materials Science, Multidisciplinary
C. Kale, S. Srinivasan, S. Sharma, B. C. Hornbuckle, R. K. Koju, S. Grendahl, K. Darling, Y. Mishin, K. Solanki
Summary: This study demonstrates exceptional fatigue strength of a microstructurally stable NC Cu3at.%Ta alloy, surpassing that of previous nanocrystalline materials and comparable to tool steels. Postmortem characterization and atomistic simulations reveal the underlying mechanism of diffuse damage accumulation, leading to more uniform distribution of damage across the microstructure. The paper highlights a design strategy to develop advanced structural alloys with exceptional fatigue resistance.
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.