Article
Materials Science, Multidisciplinary
Quanfeng Han, Xin Yi
Summary: As the average grain size decreases, the reduction in intragranular dislocation storage ability is revealed as the underlying mechanism of the breakdown of Hall-Petch behavior in nanocrystalline (NC) metals. The prediction of the critical grain size for the HP-inverse HP transition of NC metals agrees well with experimental results, showing remarkable ductility enhancement in the inverse HP region dominated by harmonized deformation of grain boundaries and grain interior. Additionally, the increase in grain boundary strength leads to enhancement in yield strength and delay in occurrence of the inverse HP behavior in NC metals.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Xu Li, Xiaotao Li
Summary: The tensile yield strength of coarse-grained thin films and wires is size-dependent, showing a "smaller is weaker" phenomenon, leading to a deviation from the Hall-Petch relationship. To address this issue, a modified Hall-Petch relation is proposed by considering the influence of free-surface on lattice dislocation pileup. The modified relations, written as sigma f = sigma 0 + ck0d-1/2 for films and sigma f = sigma 0 + 2 - cck0d-1/2 for wires, where c = cos(pi d/2D) and D is the thickness or diameter of the samples, demonstrate good agreement with experimental results, with a relative error within 15%.
Article
Engineering, Mechanical
Balaji Selvarajou, Mark Hyunpong Jhon, R. Ramanujan, Siu Sin Quek
Summary: Titanium aluminide alloys exhibit excellent mechanical properties at high temperatures, but their microstructure shows highly anisotropic behavior, and the associated micromechanics are not well understood. In this study, crystal plasticity finite element techniques are used to establish structure-property relationships and reveal the complex interplay between lamellar orientation, structural length scale, temperature, and stress state. The results provide insights for improving damage tolerance in these alloys.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Nanoscience & Nanotechnology
Kai Yao, Xiaohua Min
Summary: This study investigated the effect of grain size on the tensile properties of Ti-15Mo alloy, revealing that the impact decreased with increasing strain and eventually became negative. A dynamic Hall-Petch relation was established based on effective grain size, showcasing twin activation, twin suppression, and various interactions.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Seok-Jun Park, Kyung-Shik Kim, Jee-Hyun Kang, Sung-Joon Kim
Summary: In this study, the Hall-Petch relationship was investigated for austenitic stainless steels with either 0.3 wt% C or N. It was found that the nitrogen-containing steel exhibited a higher Hall-Petch slope, indicating that a higher stress was required to activate the dislocation source in adjacent grains. The researchers suggested that the presence of nitrogen in the steel hindered cross-slip at the grain boundaries and delayed the activation of the dislocation source.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Nanoscience & Nanotechnology
Yu Wen, Bo Guan, Yunchang Xin, Chenglu Liu, Peidong Wu, Guangjie Huang, Qing Liu
Summary: The solute atom mediated Hall-Petch relations were investigated for Mg-Y, Mg-Al, Mg-Gd, and Mg-Zn alloys at a nominal solute content of 0.35 at.%. It was found that Mg-Y and Mg-Gd exhibited significantly lower Hall-Petch slope (k) values (220 MPa·μm(1/2) and 285 MPa·μm(1/2), respectively) compared to Mg-Al and Mg-Zn (324 MPa·μm(1/2) and 322 MPa·μm(1/2), respectively) under compression along the extrusion direction. The addition of Zn or Al led to a strong basal texture and predominantly basal slip deformation, while the addition of Gd or Y resulted in a weakened texture and activation of both {10 (1) over bar2} twinning and basal slip. This difference in deformation mechanisms contributed to the lower k values in Mg-Y and Mg-Gd alloys.
SCRIPTA MATERIALIA
(2022)
Article
Nanoscience & Nanotechnology
K. A. Darling, B. C. Hornbuckle, C. J. Marvel, V. H. Hammond, K. Solanki
Summary: The paper provides a critical assessment of the role of grain size in limiting strength gains in stable nanocrystalline metals. Using copper-tantalum binary alloys, the study explores the breakdown of classical Hall-Petch behavior and its underlying mechanisms. The results show that Cu-Ta alloys exceed traditional strength limits predicted by the Hall-Petch relationship for NC Cu.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Shuang Zhang, Fei Wang, Ping Huang
Summary: The study demonstrates that embedding graphene into nanocrystalline Cu can enhance the mechanical properties of materials, delay softening, and increase the Hall-Petch slope, which is crucial for overcoming strength limitations.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Rui Ren, Jianfeng Fan, Binshan Wang, Qiang Zhang, Weiguo Li, Hongbiao Dong
Summary: Grain refinement is an effective way to improve the mechanical properties of Mg according to the Hall-Petch theory. This study investigated the grain size dependence on the deformation microstructure, dislocation density, strain rate sensitivity, activation volume, and mechanical properties of pure Mg samples with different grain sizes. Different Hall-Petch relationships were found for pure Mg samples with varying grain sizes, providing insights for improving the mechanical properties of Mg.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Rui Ren, Jianfeng Fan, Binshan Wang, Qiang Zhang, Weiguo Li, Hongbiao Dong
Summary: This study investigates the effect of grain size on the mechanical properties of pure Mg, and explores its Hall-Petch relationship and the mechanism behind its transformation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Zhenbo Zhu, Hefei Huang, Awen Liu, Zhiyong Zhu
Summary: In this study, the irradiation tolerance and plastic degradation of Alloy 800H in molten salt reactors were investigated. The microstructure changes were characterized using transmission electron microscopy, and the plastic mechanical properties were determined through nanoindentation testing. The results showed that the characteristics of Frank loops can be used to calculate the yield stress contribution, and increasing loading rates led to a decrease in the measured yield stress.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Maoyuan Jiang, Ghiath Monnet, Benoit Devincre
Summary: The study revealed that the back stress and associated strain hardening are independent of grain size at low strain, while the grain size effect is controlled by increasing the critical resolved shear stress (CRSS) when decreasing grain size. The evolution of the CRSS amplitude is controlled by two competing strengthening mechanisms, justifying the generic 1/d dependent form of the Hall-Petch law observed in simulations and experiments.
Article
Materials Science, Coatings & Films
H. S. Maharana, K. Mondal
Summary: This study successfully developed pure Ni and Ni-MoS2 bulk nano-crystalline electrodeposited coatings and analyzed their mechanical and wear behavior. The crystallite size of Ni in Ni-MoS2 coatings varied with different loading levels of MoS2, showing an inverse Hall-Petch relation in hardness values. The wear resistance of Ni-MoS2 coatings was significantly improved compared to pure Ni electrodeposit, possibly due to the higher hardness caused by dispersion hardening. The wear behavior of the Ni-MoS2 coatings was correlated with crystal orientation, coating morphology and hardness to establish a possible abrasive wear mechanism.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Jing Xu, Bo Guan, Yunchang Xin, Xuedong Wei, Guangjie Huang, Chenglu Liu, Qing Liu
Summary: In this study, a weak texture dependence of Hall-Petch slope (k) in a rare-earth containing Mg-2Zn-1Gd plate was reported, with similar k values for TD-tension and RD-tension. This characteristic can be well predicted by the compound use of activation stress difference and geometric compatibility factor, attributing the mechanism to the activation of a high fraction of additional deformation mode.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Frederic Sansoz, Xing Ke
Summary: The breakdown of grain-size strengthening to softening mechanisms in nanocrystalline alloys, particularly with regards to grain-boundary solute segregation, has been investigated through large-scale simulations. Three concentration-dependent regimes of plasticity were identified, including classical segregation strengthening, shear band-induced softening, and a previously unknown plateau of maximum strengths for intermediate solute contents. The findings highlight the complex roles of solute segregation and interfacial plasticity mechanisms in nanocrystalline alloys.
Article
Nanoscience & Nanotechnology
Ahmad Mirzaei, Peter D. Hodgson, Xiang Ma, Vanessa K. Peterson, Ehsan Farabi, Gregory S. Rohrer, Hossein Beladi
Summary: This study investigated the influence of parent austenite grain refinement on the intervariant boundary network in a lath martensitic steel. It found that refining the parent austenite grain led to a decrease in the fraction of certain boundaries in the martensite and an increase in the connectivity of low energy boundaries, ultimately improving the impact toughness.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
N. L. Church, C. E. P. Talbot, L. D. Connor, S. Michalik, N. G. Jones
Summary: Metastable beta Ti alloys based on the Ti-Nb system have attracted attention due to their unique properties. However, the unstable cyclic behavior of these alloys has hindered their widespread industrial use. Recent studies have shown that internal stresses, including those from dislocations, may be responsible for this behavior. This study demonstrates that inter-cycle thermal treatments can mitigate the unstable cyclic behavior, providing a significant breakthrough in our understanding of Ti-Nb superelastic materials.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Di Zhao, Chenchen Zhao, Ziyang Xiu, Jiuchun Yan
Summary: This study proposes a novel strategy for achieving the bonding of SiC ceramic and Al alloy using ultrasound. The ultrasound promotes the dissolution of Al into the solder, activating the solder and triggering the interfacial reaction between SiC ceramic and solder. With increasing ultrasonic duration, the bonding between SiC and Al transitions from partial to full metallurgical bonding.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Kang Du, Yang Zhang, Guangda Zhao, Tao Huang, Liyuan Liu, Junpeng Li, Xiyu Wang, Zhongwu Zhang
Summary: This paper systematically investigated the evolution of microstructure in Fe-Ni-Co-Al polycrystalline alloys and its effects on mechanical properties. The results revealed that the migration of grain boundaries in different processes is driven by different factors, which impacts the grain orientation and precipitate formation. In the process of directional recrystallization, grains with specific orientations grow in the grain boundary region and form the dominant orientation, while grains with lower migration rate form the minor orientation. The alloy produced through directional recrystallization exhibited good recoverable strain and superelastic strain, while the alloy produced through solid solution treatment showed no evident superelastic behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Edohamen Awannegbe, Liang Chen, Yue Zhao, Zhijun Qiu, Huijun Li
Summary: This study employed laser metal deposition to additively manufacture Ti-15Mo wt% alloy, and subsequently subjected it to post-fabrication uniaxial thermomechanical processing. The results showed that different zones in the microstructure remained after processing, and deformation mechanisms mainly involved slip and martensite formation. The compressive mechanical properties were found to be dependent on strain rate, with higher flow stress and compressive strength observed at higher strain rates. Grain structure homogenisation was not achieved, leading to anisotropic tensile properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Reza Khatib Zadeh Davani, Enyinnaya George Ohaeri, Sandeep Yadav, Jerzy A. Szpunar, Jing Su, Michael Gaudet, Muhammad Rashid, Muhammad Arafin
Summary: This research aims to investigate the effect of roughing and finishing reductions on crystallographic texture. The results show significant heterogeneity in the centerline region, with higher intensity of certain textures. Drop Weight Tear Test indicates that steel specimens with lower and medium reductions exhibit superior low-temperature impact toughness compared to steel with higher reductions. The electrochemical hydrogen charging experiments confirm the presence of internal hydrogen cracks only in steel with lower and medium reductions.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Flavio De Barbieri, Denis Jorge-Badiola, Rodrigo Allende, Karem Tello, Alfredo Artigas, Franco Perazzo, Henry Jami, Juan Perez Ipina
Summary: This study examines the effect of Cr additions on the mechanical behavior of TWIP steel at temperatures ranging from 25°C to 350°C. The results indicate that different temperature-dependent strengthening mechanisms, including mechanical twinning, Dynamic Strain Aging, and slip bands, are at play. The stacking fault energy (SFE) influences the percentage of mechanical twinning, which in turn affects the strain hardening rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Hanlin Peng, Siming Huang, Ling Hu, Bingbing Luo, Liejun Li, Ian Baker
Summary: This study explores the weldability, microstructures, and mechanical properties of two L1(2)-nanoparticle-strengthened medium-entropy alloys after electron beam welding (EBW). The results show that strong yet ductile defect-free joints were produced, with larger grain sizes in the fusion zones compared to the heat-affected zones and base materials. Both EBWed MEAs exhibited high yield strengths, high ultimate tensile strengths, and good fracture strains at 77 K. The V-doping improved the cryogenic mechanical properties of the TMT MEA.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Yongxin Wang, Lei Chen, Lizi Shao, Shuo Hao, Motomichi Koyama, Xingzhou Cai, Xiaocong Ma, Miao Jin
Summary: This study investigated the tensile deformation behavior of an Mn-N bearing lean duplex stainless steel with metastable austenite. The results showed that the strain rate had significant influence on the work hardening, strain-induced martensitic transformation, and fracture mechanism.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Jong Woo Won, Seulbi Lee, Hye-Jeong Choe, Yong-Taek Hyun, Dong Won Lee, Jeong Hun Lee
Summary: Cold-rolled pure titanium showed improved sheet formability after undergoing cryogenic-deformation treatment. This treatment increased the thinning capability of the titanium and suppressed cracking during sheet forming. The formation of twins during deformation contributed to high thinning capability and increased strength through grain refinement and dislocation accumulation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Handong Li, Lin Su, Lijuan Wang, Yanbin Jiang, Jiahui Long, Gaoyong Lin, Zhu Xiao, Yanlin Jia, Zhou Li
Summary: Homogenization heat treatment is a key procedure in controlling the second phase, enhancing composition uniformity, and workability of as-cast Cu-15Ni-8Sn alloy. This study found that electropulsing treatment (EPT) can significantly reduce treatment temperature and time, improve elongation and overall mechanical properties of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Yuxuan Wang, Juntao Zou, Lixing Sun, Yunfei Bai, Zhe Zhang, Junsheng Cheng, Lin Shi, Dazhuo Song, Yihui Jiang, Zhiwei Zhang
Summary: A novel mechanical-heat-electricity synergistic method was proposed to enhance the mechanical properties of Cu-15Sn-0.3Ti alloy by forming annealing twins (ATs). The combination method of Rotary swaging (RS) and Electric pulse treatment (EPT) successfully induced recrystallization and refinement of the microstructure, leading to a significant increase in the strength of the alloy within a short time.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Zhiyi Ding, Jiangtao Xie, Tong Wang, Aiying Chen, Bin Gan, Jinchao Song
Summary: This study demonstrated the Ta-induced strengthening of CoCrNi-AlTi MEAs using nanoscale heterogeneous coherent precipitates. The addition of Ta and aging treatments significantly enhanced the mechanical properties of the alloy, including yield strength, ultimate tensile strength, and elongation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Z. Y. You, Z. Y. Tang, B. Wang, H. W. Zhang, P. Li, L. Zhao, F. B. Chu, H. Ding
Summary: The mechanical properties and microstructural evolution of C-doped TRIP-assisted HEA under dynamic loading conditions were systematically investigated in this study. The results showed that dynamic tensile deformation led to an increase in yield strength and a decrease in ultimate tensile strength, with a trend towards increased total elongation. The primary deformation mechanisms shifted from TRIP and TWIP effects to deformation twinning and dislocations. The presence of carbides formed through C-doping hindered dislocation slip and promoted the activation of multiple twinning systems.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
Feng Qin, Feihu Chen, Junhua Hou, Wenjun Lu, Shaohua Chen, Jianjun Li
Summary: Plastic instability in strong multilayered composites is completely suppressed by architecting nanoscale BCC Nb crystalline-amorphous CuNb interfaces.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)