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
Materials Science, Multidisciplinary
Jianming Li, Yuting Wu, Hongjun Zhang, Xingzhong Zhang
Summary: During hot deformation of nickel-based superalloys, dislocations undergo various processes such as production, annihilation, and rearrangement into substructures, which have a significant impact on the dynamic recrystallization process. Understanding the relationship between dislocation substructures and recrystallization mechanisms is crucial. Through isothermal compression experiments, the evolution of dislocation substructures and associated recrystallization behaviors were studied in a coarse-grained Co-free nickel-based superalloy. The results showed that dislocation substructures governed the dynamic recrystallization mechanisms and acted as precursors for new grains, while dynamic recovery promoted the transition of dislocation substructures. Continuous dynamic recrystallization was influenced by independent substructures within deformed grains, while discontinuous dynamic recrystallization was influenced by substructures attached to original grain boundaries. The sacrifice of dislocation substructures drove recrystallization kinetics, as the recrystallized volume fraction was inversely proportional to the content of sub-boundaries after deformation. The distance between adjacent sub-boundaries determined the new grain size during continuous dynamic recrystallization, and a weight model was proposed for grain size prediction based on continuous rotation processing.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Physical
Jin Yang, Jiao Luo, Xiangyang Li, Miaoquan Li
Summary: This study investigates the correlation between microstructure and deformation-solution parameters of GH4586 superalloy through isothermal compression, solution treatment, EBSD, and TEM observations. It clearly illustrates the mechanisms of recrystallization, twin evolution, gamma' precipitation, and their interaction. The results show that the processes of dynamic and static recrystallization are controlled by different mechanisms, and the evolution of twin boundaries during deformation is influenced by losing twin's identity and nucleation of new twins. Fine gamma' precipitates hinder recrystallization but also have a noticeable influence on the formation of new twins.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Yu-Chi Xia, Xiao-Min Chen, Yong-Cheng Lin, Xian-Zheng Lu
Summary: The hot deformation characteristics of GH4169 superalloy were investigated, and the effects of deformation parameters on flow curves and annealing twins were discussed. It was found that the deformation temperature greatly affected the shapes of flow curves, and the evolution of annealing twins was sensitive to deformation degree, temperature, and strain rate.
Article
Materials Science, Multidisciplinary
Fei Sui, Teng An, Shuqi Zheng, Liqiang Chen, Shuyin Li
Summary: The influence of effective strains on the corrosion behavior of GH4710 superalloy in chloride solutions was studied, and the corrosion resistance was explained by analyzing the microstructure and grain boundary properties.
Article
Nanoscience & Nanotechnology
Xuehui Yan, Yong Zhang, Yu Zou
Summary: In this study, it was found that a cold-rolled bcc Zr50Ti35Nb15 medium-entropy alloy exhibited superior tensile ductility with near-superplastic behavior at elevated temperatures. The high-density dislocations induced by cold rolling facilitated dynamic recrystallization, which relieved stress concentration and enhanced its tensile ductility. This study demonstrates the near-superplastic behavior in bccMPEAs and suggests an effective route to enhance ductility in typically brittle bcc MPEAs through dynamic recrystallization.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Jieke Zhang, Yu Cao, Yuhao Gong, Jun Xiao, Yulong Zhu, Rui Luo, Qubo He, Qing Liu
Summary: In this study, isothermal hot compression tests were conducted on Inconel X-750 alloy at elevated temperatures. The flow stress was accurately predicted using a back-propagation artificial neural network model. The optimal processing parameters were determined based on a modified hot processing map coupled with the variation of twin boundaries fraction. The possibility of grain boundary engineering via hot deformation was also evaluated. The high-temperature flow behavior and microstructure characterization showed the predominant softening mechanism and the contributions from different recrystallization mechanisms.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Yao Lin, Luyi Han, Guangchun Wang
Summary: In this study, pure nickel wires were subjected to torsion and annealing grain boundary modification to investigate the effect of thermomechanical process (TMP) on grain boundary characteristics and plasticity. The findings show that the elongation of the samples subjected to the optimal TMP significantly increased while tensile strength was minimally affected. A new micro index was proposed to comprehensively evaluate the coupling effect between grain size and grain boundary characteristic distribution on material plasticity.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Yue Sheng, Hongda Yang, Wentao Ma, Xiaoyu Jiang
Summary: This paper describes the interaction model between discrete dislocation emission and the grain boundary at the crack tip of microscale grain. The distribution and penetration of dislocations have a new effect on the crack. The results show that the main crack tends to propagate in large grain boundary angle and in small grain size crystalline materials, while wedge crack in the grain boundary tends to initiate with large grain boundary angle and in large grain size crystalline materials.
INTERNATIONAL JOURNAL OF FRACTURE
(2023)
Article
Materials Science, Multidisciplinary
J. Zimmerman, A. Aviv, Y. Elfassy, A. Bisht, L. Klinger, E. Rabkin
Summary: The effect of surface topography on grain boundary migration in thin films has been investigated in this study. In pure bulk Ni samples, large protrusions resembling downscaled terrestrial mountains were observed near grain boundaries after mild cold deformation and subsequent annealing. These protrusions, called 'thermal ridges', decrease in size with increasing annealing time and degree of deformation. A kinetic model of ridges based on the modified Mullins' model was developed to explain this phenomenon. The combination of experimental and modeling results provides new insights into the formation of hillocks in thin polycrystalline films.
Article
Materials Science, Multidisciplinary
Kai Hu, Jun Yi, Bo Huang, Xilei Bian, Gang Wang
Summary: This study overcomes the trade-off between strength and ductility in pure nickel materials by using grain boundary relaxation and optimizing grain size. The results show that grain boundary relaxation can improve both tensile strength and uniform elongation of nickel, and enhance the plastic deformation through controlling dislocation activities.
APPLIED MATERIALS TODAY
(2022)
Article
Metallurgy & Metallurgical Engineering
Li Fulin, Fu Rui, Bai Yunrui, Meng Lingchao, Tan Haibing, Zhong Yan, Tian Wei, Du Jinhui, Tian Zhiling
Summary: GH4096 alloy is used in advanced gas turbine engines due to its excellent properties. In this study, GH4096 was processed through an advanced cast and wrought route to avoid expensive power metallurgy (P/M) route. The effects of initial grain size and strengthening phase on hot deformation behavior and dynamic recrystallization were studied.
ACTA METALLURGICA SINICA
(2023)
Article
Chemistry, Physical
Ke Tang, Zhibo Zhang, Jin Tian, Yake Wu, Feng Jiang
Summary: The study on hot deformation behaviors of supersaturated Inconel 783 superalloys revealed the optimal temperature and strain rate range to be 1100-1200 degrees C and near or below 0.1 s(-1) but higher than 0.01 s(-1). The microstructural observation showed that the recrystallized degree and grain size were affected by temperature and strain rate differently.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Metallurgy & Metallurgical Engineering
Guo-zheng Quan, Yu-qing Zhang, Pu Zhang, Yao-yao Ma, Wei-yong Wang
Summary: This study developed an improved twin density model to investigate the relationship between low-energy twin boundary density (BLD Sigma 3n) and grain size, stored energy in thermal-plastic deformation process and solved it for Nimonic 80A superalloy based on EBSD statistical results. The results showed that BLD Sigma 3n increases with increasing stored energy and decreasing grain size, and higher BLD Sigma 3n with finer grains corresponds with lower temperatures and higher strain rates.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Engineering, Manufacturing
Dominic D. R. Peachey, Christopher P. Carter, Andres Garcia-Jimenez, Anugrahaprada Mukundan, Donovan N. Leonard, Marie-Agathe Charpagne, Zachary C. Cordero
Summary: Metal additive manufacturing processes often result in fine grain structures, which affect high-temperature creep properties. This study demonstrates how directional recrystallization can create large columnar grains, manipulate crystallographic texture to minimize thermal stresses, and selectively enhance fatigue or creep performance of additively manufactured Ni-base superalloys.
ADDITIVE MANUFACTURING
(2022)
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)