Article
Materials Science, Multidisciplinary
Y. J. Lu, C. C. Guo, H. S. Huang, J. A. Gao, H. R. Qin, W. H. Wang
Summary: The study investigates the aging process of supercooled Cu50Zr50 glass-forming liquid, revealing a multi-mode dynamics accompanied by a quantized hierarchy of mobile clusters. An aging model is proposed to describe the aging dynamics as a weighted average over quantized dynamic modes. This model predicts the heterogeneous dynamics in aging and equilibration of supercooled metallic liquids, shedding light on the intrinsic aspects influencing the aging process.
Article
Materials Science, Multidisciplinary
Y. Tang, Q. K. Zhao, H. F. Zhou, W. Hu, T. D. Xu, L. Zheng, R. K. Nutor, X. D. Wang, Q. P. Cao, D. X. Zhang, G. Sha, H. K. Wang, J. Z. Jiang
Summary: Pressure annealing has the potential to tailor the microstructure and mechanical behavior of metallic glasses, as demonstrated through a combination of experiments, simulations, and machine learning in this study. The transition of deformation mode from localized to delocalized in pressure-annealed metallic glasses is mainly governed by variations in atomic packing structure induced by pressure annealing, providing insights into fine-tuning their mechanical properties.
Article
Chemistry, Multidisciplinary
Debaditya Chatterjee, Ajay Annamareddy, Jittisa Ketkaew, Jan Schroers, Dane Morgan, Paul M. Voyles
Summary: Surface dynamics near the glass transition temperature of metallic glasses can be suppressed by coating the surface with a thin layer of amorphous carbon, as shown by electron correlation microscopy and molecular dynamics simulations. Additionally, mobility near the surface occurs through atomic caging and hopping, with a correlation between slow dynamics and high cage-breaking barriers. Surface and bulk dynamics collapse together as temperature is rescaled by their respective glass transition temperatures.
Article
Chemistry, Physical
Shuo Li, Ping Huang, Fei Wang
Summary: This study demonstrates that pronounced beta-relaxation can be achieved in Cu50Zr50 MG, effectively improving the plasticity of CuZr alloys. Simulation results and analysis suggest that higher degree of heterogeneity generated in severely deformed regions is responsible for the unusual pronounced beta-relaxation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
W. Porter Weeks, Katharine M. Flores
Summary: Researchers have used geometric alignment and density-based clustering algorithms to quantitatively describe the short-range atomic structure in the liquid state of five metallic glass-forming systems. They found that each liquid is composed of geometrically-similar atomic clusters, and the distribution of these clusters is inversely correlated to the glass-forming ability observed experimentally.
Article
Materials Science, Multidisciplinary
Xiaodi Liu, Quanfeng He, Wenfei Lu, Ziqing Zhou, Jinsen Tian, Dandan Liang, Jiang Ma, Yong Yang, Jun Shen
Summary: Metallic glasses have a non-uniform structure and dynamics at the nanoscale, with static and dynamic heterogeneities being crucial for their deformation mechanism. Machine learning can be used to learn defects in MGs from atomic trajectories and identify which atoms behave like liquids under stress.
SCIENCE CHINA-MATERIALS
(2022)
Article
Chemistry, Physical
Xudong Yuan, Daniel Sopu, Kaikai Song, Juergen Eckert
Summary: Increasing free volume in metallic glasses rejuvenates them, but this free volume can be annihilated under deformation leading to structural relaxation and strain-hardening. Highly rejuvenated metallic glasses experience stress-driven structural and residual stress relaxation during cycling deformation, eventually reaching a more stable state but unable to recover their initial state.
Article
Materials Science, Ceramics
Tuo Wang, Lianshun Zhang, Qiqi Hou, Qi Hao, Jichao Qiao
Summary: The plasticity of Fe75Mo5P13C7 BMG can be improved by annealing at low temperature due to nano-crystallization and remaining free volume. The correlation of plasticity with micro-structure, relaxation, and free volume characteristic varies in Fe75Mo5P13C7 BMG with its annealed state under different temperatures. The plasticity will be largest when the ratio of nanocrystals is equivalent to the free volume.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Review
Chemistry, Physical
D. Sopu
Summary: The complex nature of shear banding and the disordered structure of metallic glasses pose challenges in understanding the mechanisms of strain localization and shear band formation. The percolation of shear transformation zones (STZs) is widely accepted as the atomic-scale mechanism for shear banding. This review provides an up-to-date assessment of the STZ-Vortex mechanism and its applications in understanding shear band dynamics and deformation mechanisms in metallic glasses. It also highlights unresolved issues where the STZ-Vortex model could be effectively applied.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
V Guder, S. Sengul, M. Celtek, U. Domekeli
Summary: Pressure was found to have an effect on the local microstructure in amorphous Pd80Si20 alloy, with an increase in pressure leading to a higher glass transition temperature. The complexity of the local structure was attributed to the Pd atoms in face centered cubic (fcc) and icosahedral-like order, while the short-range order around Si atoms was characterized by a tri-capped trigonal prism. The topological structure and local environment of the system consisting of icosahedral-, hexagonal-, and fcc-like structural units underwent significant changes under pressure, with the short-range order developing due to the increase of icosahedral and defected icosahedral polyhedra, and Pd atoms playing a role in the formation of the amorphous state.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Materials Science, Ceramics
Xuerui Wei, Bin Xu, Pengfei Guan
Summary: We found a direct link between the mechanical heterogeneity and local structural response of metallic glasses, revealing that the mechanical heterogeneity is not only related to static atomic packing but also to the dynamic evolution of the amorphous structure.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Biochemistry & Molecular Biology
Giuseppe Porpora, Francesco Rusciano, Raffaele Pastore, Francesco Greco
Summary: Glass transition is an intriguing open issue in molecular liquids, and recent research has found that the relationship between macroscopic timescales and cage-jump quantities changes on approaching the glass transition.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Materials Science, Ceramics
Xiaochang Tang, Laiquan Shen, Huaping Zhang, Wanghui Li, Weihua Wang
Summary: Metallic glasses have potential as engineering materials, but their limited ductility is a major challenge. This study investigates the formation of nano-corrugations (NCs) in brittle metallic glasses and proposes a stress-driven cavitation process as the underlying mechanism. The findings shed light on the understanding of dynamic fracture propagation in amorphous materials and have implications for predicting damage development.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Nanoscience & Nanotechnology
X. Yuan, D. Sopu, F. Spieckermann, K. K. Song, S. Ketov, K. G. Prashanth, J. Eckert
Summary: Rejuvenation is the reverse process of relaxation in metallic glasses, which increases their free volume and brings them to a higher energy state. This study explores the controllable rejuvenation degree through a dilution procedure and identifies the maximum rejuvenation threshold. The activation of structural relaxation and the dynamic balance between free volume creation and annihilation determine the rejuvenation ability of metallic glasses. The highest degree of rejuvenation is related to the flow strain of the materials and exhibits a structure similar to shear bands.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Ceramics
Tuo Wang, Yulong Zhou, Lianshun Zhang
Summary: The correlation between the annealing time and the plasticity, chemical fluctuation and structure change of a (Zr65Cu20Fe5Al10)94Nb6 bulk metallic glass (BMG) has been studied. The research shows that the plasticity initially increases and then decreases with increasing isothermal annealing time. After 30 min of annealing, the plasticity of the (Zr65Cu20Fe5Al10)94Nb6 BMG can reach 17.3%. The as-cast (Zr65Cu20Fe5Al10)94Nb6 BMG has a homogeneous structure and chemical composition, with short-range icosahedral clusters being the main structure. However, after annealing, there is chemical heterogeneity in the Cu-rich area, and various medium-range clusters can be found in the annealed (Zr65Cu20Fe5Al10)94Nb6 BMG.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Chemistry, Physical
Rui Li, Yimo Ma, Xingshuo Liu, Ye Lu, Yifei Zhang, Pengfei Yu, Gong Li
Summary: In this study, the effect of defects on phase transition in high-entropy alloys was investigated by comparing the structure evolutions of ball-milled and as-cast samples. The ball-milled alloy exhibited a lower phase-transition-pressure and a higher fraction of hcp phase due to a higher density of defects and a lower nucleation energy barrier compared to the as-cast alloy. The findings suggest a potential approach for customizing the percentage of different phases in high-entropy alloys to improve their structure and characteristics as a novel engineering material.
Article
Materials Science, Multidisciplinary
Wei Zhao, Jiacheng Yu, Mindong Hu, Honglei Hu, Junting Luo, Gong Li
Summary: The crystallization toughening effect of Fe-based amorphous alloys under strain-heat coupling was investigated. The results showed that the alloys subjected to strain-heat coupling had a greater toughening effect due to changes in the morphology of the precipitated crystal phase and the introduction of free volume through plastic deformation, promoting the proliferation of shear bands. Excessive plastic deformation, however, resulted in direct fracture of the materials.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
X. S. Liu, R. Lia, X. F. Fan, Q. Q. Liu, X. Tong, A. X. Lia, S. Xu, H. Yang, S. B. Yu, M. H. Jiang, C. Huo, P. F. Yu, M. T. Dove, G. Li
Summary: In this study, dual-morphology B2 precipitates were obtained by thermo-mechanical processing in Co36Cr15Fe18Ni18Al8Ti4Mo1 MPEA. The dual-morphology B2 precipitates were found to enhance the yield strength and ultimate tensile strength significantly, suggesting the potential for optimizing the mechanical properties of the alloy.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
A. X. Li, P. F. Yu, Y. P. Gao, M. T. Dove, Gong Li
Summary: We describe the development of a non-equiatomic CoCrFeNi2Al0.3Ti0.25 high entropy alloy (HEA) with high-density nano-lamellar precipitates and ultrafine grain structure. The HEA annealing at 700 degrees C (CR-700) exhibits ultra-high yield strength, ultimate tensile stress, and excellent total elongation, overcoming the strength-ductility trade-off. The ultra-high strength is mainly attributed to the synergistic strengthening effects of both nano-lamellar precipitates and ultrafine grains.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Huan Zhang, Yaqi Zhang, Chen Chen, Pengfei Yu, Li-Min Wang, Gong Li
Summary: A novel high-conductivity Agx[(Ga2Te3)34(SnTe)66]100-x tellurium-based glassy system was fabricated and showed potential for thermoelectric applications. The fabricated Ag10[(Ga2Te3)34(SnTe)66]90 glass exhibited higher room-temperature conductivity, larger glass transition temperature, and ultralower thermal conductivity compared to previously reported glassy systems. This distinctive Ag-Ga2Te3-SnTe system can be further investigated in similar glassy semiconductors and also has potential applications in other fields.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Shu Xu, Xingshuo Liu, Rui Li, Xiaofeng Fan, Qingqi Liu, Aoxiang Li, Pengfei Yu, Yongyong Wang, Gong Li
Summary: Fe3Cr2CoNiAlx (x = 0.6, 0.7, 0.8, 1.0, 1.1, 1.2) high entropy alloys (HEAs) with dual-scales B2 precipitated were prepared. The microstructure changed from face-centered-cubic (FCC) and body-centered-cubic (BCC) to a single BCC structure with the increasing of Al content. By controlling the concentration of Al element in the BCC-based HEAs, the structure can be tuned to two coherent BCC phases: medium B2 (m-B2) precipitates with an average length of 200-300 nm and smaller size B2 (s-B2) precipitates with an average diameter of 10-50 nm. The Fe3Cr2CoNiAl1.2 HEA exhibited excellent compression properties, with yield strength and fracture strain of 1464 MPa and 20%, respectively. The main strengthening mechanism was determined to be precipitation strengthening. This work provides a useful mean by tailoring multi-scale phase to achieve excellent properties in BCC-based high entropy alloys.
Article
Materials Science, Multidisciplinary
Xueming Wei, Lijun Zhang, Chunzhi Zhang, Gong Li
Summary: Although most BCC-based high-entropy alloys have high strength and excellent high temperature mechanical properties, their low plasticity greatly limits their application. In this study, a new BCC/B2 AlCrFeMnNi2 high-entropy alloy with a unique sunflower-like eutectic microstructure was prepared. This alloy exhibited high yield strength, fracture strength, and compressive plastic strain, surpassing many other BCC/B2 high-entropy alloys. The excellent mechanical properties are attributed to its unique microstructure consisting of coherent interface and bimodal distribution of precipitates. Our results provide a meaningful reference for improving the plasticity of BCC-based high-entropy alloys.
Article
Materials Science, Multidisciplinary
Huan Zhang, Yaqi Zhang, Gong Li
Summary: In this study, new tellurium-based amorphous alloys [(Ga2Te3)(34)(SnTe)(66)](100-x)-Sn-x were prepared and the glass-forming region was determined to be x = 0 to 10 mol%. The increasing Sn content led to a decrease in the glass transition temperature T-g and crystallization onset temperature T-c, resulting in a decrease in the stability criterion Delta T. The crystallization kinetics were investigated using DSC, and the activation energies of the amorphous sample were determined. The crystalline products were identified and showed potential for high-performance thermoelectric glass-ceramic materials.
Article
Materials Science, Multidisciplinary
Huan Zhang, Yaqi Zhang, Pengfei Yu, Li-Min Wang, Gong Li
Summary: This paper comprehensively investigates the microstructure evolutions and crystallization kinetics of Agx-[(Ga2Te3)(34)(SnTe)(66)](100-x) (x = 6, 8 and 10%) telluride glasses under non-isothermal conditions. The XRD, TEM, and SAED techniques were used to analyze the microscopic structure. The crystalline products were identified as the SnTe phase and Ga6SnTe10 phase. The crystallization process consisted of two overlapped peaks, corresponding to the precipitation of SnTe and Ga6SnTe10. The activation energy for crystallization events decreased with increasing Ag content.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Physics, Applied
R. Li, P. F. Yu, H. Yang, M. H. Jiang, S. B. Yu, C. Huo, X. S. Liu, G. Li
Summary: Pressure-driven phase transition in metals is an effective means to induce fresh phase and tune material properties, and the CoNiFe, CoNiCr, and CoNiV multi-principal element alloys were investigated in this study. The pressure-induced phase transition from face-centered cubic to hexagonal close-packed phase was observed at different pressures for each alloy. The increase in lattice distortion degree was found to decrease the initial phase-transition-pressure, and the probability of stacking fault formation increased in the order of CoNiFe, CoNiCr, and CoNiV alloys.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Hao Yang, Xingshuo Liu, Aoxiang Li, Rui Li, Shu Xu, Mengdi Zhang, Pengfei Yu, Subo Yu, Minghui Jiang, Chao Huo, Gong Li
Summary: The effect of Si content on the microstructure evolution and corrosion properties of Al0.2CoCrFe1.5NiSix (x = 0, 0.1, 0.2, 0.3) high entropy alloys (HEAs) was systematically investigated. The addition of Si element led to a change in microstructure from single face-centered cubic (FCC) phase to a dual-phase structure composed of FCC and body-centered cubic (BCC) phases. The corrosion resistance of the alloys was affected by the Si content, with the Al0.2CoCrFe1.5NiSi0.1 HEA exhibiting the best corrosion resistance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Xinliang Shi, Gong Li, Mengdi Zhang, Hanqing Xu, Ziyang Li
Summary: A novel Co-free non-equiatomic Cr-Fe-Ni-Nb eutectic high entropy alloys (EHEAs) with lamellar microstructure showed superior corrosion resistance in 3.5 wt% NaCl solution. The increase of Nb content resulted in higher volume fraction of Laves phase and smaller interlayer distance, leading to improved corrosion resistance. The Co-free EHEAs displayed a wide passive region, low corrosion current density, and excellent repassivation ability compared to established anticorrosion alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
R. Li, X. S. Liu, A. X. Li, P. F. Yu, C. S. Feng, S. Nan, M. Xiao, Z. Guan, C. Huo, S. B. Yu, M. H. Jiang, F. X. Zhang, G. Li
Summary: This study systematically compared the microstructural and mechanical properties of samples aged under high-pressure and ambient-pressure conditions. The results showed that the high-pressure samples had a higher volume fraction of discontinuous precipitates and achieved grain refinement through high-pressure treatment. The study provides important guidance for optimizing nano-precipitates through pressure.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
G. J. Zhang, Q. G. Zhang, X. G. Wang, M. Sun, J. F. Yang, T. Hao, G. Li, H. Wang, J. G. Liu, Q. F. Fang, X. P. Wang
Summary: In this study, a newly developed equal channel angular pressing (ECAP) route BC-UD2 was used to extrude Fe9Cr1.5W0.7Si ferrite/martensitic steel, and the effect of microstructural evolution on the internal friction (IF) behavior was systematically investigated. The microstructural characterization revealed a transformation from an initial ferrite/martensitic structure to a fine laminar structure with a roughly 45 degree inclination to the extrusion direction (ED), accompanied by the evolution of texture. The dissolution of M23C6 and MX phases after extrusion led to a decrease in the Zener-Smith dragging force. The correlation between microstructure characterization results and IF behavior demonstrated the accuracy and reliability of the IF technique for studying the recrystallization behavior of structural materials in nuclear reactors.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Astronomy & Astrophysics
MingHui Jiang, SuBo Yu, BenCong Lai, FuXiang Zhang, Dong Ma, T. Martin Dove, Gong Li
Summary: Crystallography only provides information about the average atomic structure of a crystal, while the combined scattering method and Reverse Monte Carlo (RMC) simulation have the unique advantage of providing multiple information about a crystal, including the average atomic structure, atomic spacing, bond angles, orientation, and deformation of the structural polyhedron at the local scale. Recently, the RMC method has seen rapid experimental and theoretical development with the help of third-generation synchrotron and spallation neutron sources. Additionally, the RMC method is widely used to study the local fluctuations and fine structure of disordered materials.
SCIENTIA SINICA-PHYSICA MECHANICA & ASTRONOMICA
(2023)
