Article
Chemistry, Physical
T. S. Orlova, T. A. Latynina, M. Y. Murashkin, F. Chabanais, L. Rigutti, W. Lefebvre
Summary: The paper investigates the effect of high pressure torsion on the microstructure, mechanical properties, and electrical conductivity of Al-0.53Mg-0.27Zr alloy preliminarily aged at T = 375 degrees C for 366 h. It was found that HPT processing leads to a significant increase in strength and good electrical conductivity and ductility in the alloy. The study also highlights the key role of Mg alloying elements in strengthening the material.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Manufacturing
Marta Lipinska, Florian Pixner, Ireneusz Szachogluchowicz, Florian Mittermayr, Cyrill Grengg, Norbert Enzinger, Malgorzata Lewandowska
Summary: In this study, an attempt was made to weld course and ultrafine-grained Al-Mg-Si alloy using electron beam welding. The welding parameters were selected to reduce energy input and minimize the evaporation of elements with high vapor pressure. The ultrafine-grained microstructure resulted in smaller grains in the fusion zone and heat-affected zone, leading to higher mechanical strength. The weld efficiency was 80% for coarse alloy and 68% for ultrafine-grained sample compared to the coarse-grained base material. The rupture in both welds occurred in the columnar dendritic area characterized by elongated dendrites and cube texture.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Chemistry, Physical
Igor C. dos Santos, Eric M. Mazzer, Roberto B. Figueiredo, Terence G. Langdon, Pedro Henrique R. Pereira
Summary: Experiments were conducted to investigate the microstructural evolution of an Al-5.7Zn-1.8Mg-2.1Cu alloy subjected to torsional straining. The material exhibited two consecutive hardening stages during high-pressure torsion (HPT) processing. The first stage involved the accumulation and rearrangement of dislocations, resulting in the formation of fine cells/subgrains. The second stage involved the fragmentation of second phase particles and the development of highly elongated grains.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
I Vysotskii, S. Malopheyev, S. Mironov, R. Kaibyshev
Summary: Low-temperature friction-stir welding is successfully used for joining ultrafine-grained Al-Mg-Mn alloy, preserving the microstructure and second-phase particles, and achieving nearly-100% joint efficiency. The deformation behavior and strengthening mechanisms of the welded joints are studied.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Nguyen Q. Chinh, Maxim Yu Murashkin, Elena Bobruk, Janos L. Labar, Jeno Gubicza, Zsolt Kovacs, Anwar Q. Ahmed, Verena Maier-Kiener, Ruslan Z. Valiev
Summary: This study discovered ultralow-temperature superplasticity in commercial 7xxx Al alloy for the first time, providing a foundation for the development of new technologies to manufacture complex-shaped metallic parts with enhanced service properties.
MATERIALS RESEARCH LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Denise C. Machado, Paula Cibely Alves Flausino, Yi Huang, Paulo Roberto Cetlin, Terence G. Langdon, Pedro Henrique R. Pereira
Summary: Experiments were conducted to assess the effect of processing temperature on the hardness evolution, microstructure and the flow properties of an annealed Al-3Mg alloy processed by high-pressure torsion (HPT) at either 300 or 450 K. The results show that HPT processing at room temperature (RT) leads to higher microhardness values and a more uniform hardness distribution compared to processing at 450 K. The metal processed at RT exhibits enhanced strength and superplastic flow during deformation at 523 K, while the alloy processed at 450 K shows limited elongation due to abnormal grain coarsening.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Xinkui Zhang, Liejun Li, Zhi Wang, Hanlin Peng, Songjun Chen, Tao Ban, Jixiang Gao, Zhengwu Peng
Summary: In this study, an Al-La-Mg-Mn alloy with a ultrafine-grained (UFG) structure was fabricated using powder hot-extrusion technique, which exhibited a high-volume fraction of bimodal sub-micron intermetallics. The unique structure suppressed the grain growth and maintained excellent thermal stability, with a slight increase in grain size after thermal exposure. Moreover, the UFG structure showed a remarkable combination of strength and ductility. The UFG structure decorated with bimodally distributed intermetallics presents a promising microstructural design for UFG-structured alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Anette B. Hagen, Sigurd Wenner, Ruben Bjorge, Di Wan, Calin D. Marioara, Randi Holmestad, Inga G. Ringdalen
Summary: Al-Mg-Si (6xxx series) alloys exhibit strong mechanical properties but are weakened by a soft precipitation free zone (PFZ) near grain boundaries during heat treatment, reducing material ductility. This study employs nanoindentation and microstructure characterization to quantitatively analyze these alloys. Experimental results confirm that the PFZ weakens the material, while an adjacent region exhibits increased hardness due to a higher density of precipitates. This previously unrecognized harder zone has important implications for the mechanical properties of large-grained aluminum alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
M. Osorio-Garcia, K. Suarez-Alcantara, Y. Todaka, A. Tejeda-Ochoa, M. Herrera-Ramirez, O. Hernandez-Silva, F. Cruz-Gandarilla, J. G. Cabanas-Moreno
Summary: Bulk materials of the Mg-Ni-Nb2O5 alloy with ultrafine grain structure produced by high-pressure torsion (HPT) processing exhibit faster hydrogenation kinetics and higher storage capacities compared to initial mild-milled powder mixtures. However, the storage capacities are limited by the formation of MgO after several hydrogenation cycles. Despite this limitation, the material can be handled and stored without special precautions and maintains its fast activation in posterior hydrogenation treatments for several months.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Metallurgy & Metallurgical Engineering
I Vysotskiy, K. Kim, S. Malopheyev, S. Mironov, R. Kaibyshev
Summary: This study aimed to improve the superplastic ductility of friction-stir welded joints of ultrafine-grained (UFG) Al-Mg-Sc-Zr alloy. The UFG material was produced at elevated temperature to suppress abnormal grain growth, but the new approach resulted in a high fraction of low-angle boundaries, hindering grain-boundary sliding. Thus, superplastic deformation was primarily concentrated in the fully-recrystallized stir zone.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2022)
Article
Nanoscience & Nanotechnology
Marta Ciemiorek, Witold Chrominski, Cezary Jasinski, Malgorzata Lewandowska
Summary: The article discusses the evaluation of ultrafine-grained plates of commercial aluminium alloy 5754, achieved through a hybrid Severe Plastic Deformation process. This process yielded substantial enhancements in mechanical properties and typical anisotropy parameters, making it suitable for the production of high-strength plates.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Takahiro Masuda, Yongpeng Tang, Intan Fadhlina Mohamed, Zenji Horita
Summary: In this study, an AZ61 Mg alloy was processed by high-pressure torsion (HPT) to refine the grain size. Using a facility with an upscaled capacity of 500 ton, 30 mm diameter disks were processed under 6 GPa. Tensile tests at elevated temperatures showed that the grain size was reduced to around 320 nm after HPT processing at 423 K for 10 turns. This grain size reduction led to a superplastic elongation of more than 400% at 473 K with an initial strain rate of 1.0 x 10(-3) s(-1). Comparing the results with conventional 10 mm diameter disks, it was found that the total elongation was invariably higher for the 30 mm disks, and this difference was attributed to the anisotropy due to material flow.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Balint Boldizsar, Peter Jenei, Anwar Q. Ahmed, Maxim Yu Murashkin, Ruslan Z. Valiev, Nguyen Q. Chinh
Summary: The study found that the ultrafine-grained alloy exhibited super ductility in the low temperature range, with relatively high strain rate sensitivity and low activation energy.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Ying Chen, Xu Yuan, Jiahui Dong, Shenbao Jin, Gang Sha, Yihang Yang, Houan Zhang, Chuanting Wang, Nong Gao, Marco J. Starink
Summary: In this study, we successfully increased the tensile strength and ductility of AA6xxx series aluminum alloy through high-pressure torsion (HPT) processing. Analysis by X-ray diffraction and transmission electron microscopy revealed the formation of a high density of dislocations and a decrease in grain size. Atom probe tomography showed strong solute segregation on ultrafine-grained boundaries. It was found that solute segregation at dislocations and on grain boundaries is the dominant strengthening mechanism in the HPT processed 6xxx series Al-Mg-Si alloy.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Physical
Marta Lipinska
Summary: In this study, the welding of coarse- and ultrafine-grained Al-Mg-Si alloy using friction stir welding was attempted. The results showed that FSW can be successfully applied to materials with thermally unstable microstructures, and plastic deformation can improve the mechanical properties and microstructure of the materials.
Article
Materials Science, Multidisciplinary
Grigory S. Dyakonov, Georgy I. Raab, Mikhail V. Pesin, Alexander V. Polyakov, Irina P. Semenova, Ruslan Z. Valiev
Summary: A two-phase titanium alloy with an ultrafine-grained structure was successfully produced using equal-channel angular pressing. This alloy showed significant strength increase at room temperature and exhibited superplastic-like behavior during compression at high temperatures. The study utilized this behavior to investigate the forging process of the alloy and found that the forged alloy had significantly higher strength properties compared to standard processing. The origin of this superior behavior in the ultrafine-grained alloy was discussed.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Crystallography
Boris B. Straumal, Roman Kulagin, Brigitte Baretzky, Natalia Yu. Anisimova, Mikhail V. Kiselevskiy, Leonid Klinger, Petr B. Straumal, Olga A. Kogtenkova, Ruslan Z. Valiev
Summary: This review discusses the intersection of phase transformations, severe plastic deformation (SPD), and high-entropy alloys (HEA) in materials science. The use of SPD techniques enables the determination of single-phase regions and the formation of nanoparticles in HEAs, influencing their composition, structure, and properties.
Article
Chemistry, Physical
G. I. Raab, I. S. Kodirov, D. A. Aksenov, R. Z. Valiev
Summary: This study aims to investigate the features of the initial Ti Grade 4 structure and their effects on the structure and properties changes during equal channel angular pressing (ECAP). The results show that ECAP of titanium in an initial martensitic state leads to the formation of a finer and more homogeneous structure, resulting in more significant hardening compared to the hot-rolled state.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Sylwia Rzepa, Zuzanka Trojanova, Jan Dzugan, Ruslan Z. Valiev, Martina Koukolikova, Daniel Melzer, Michal Brazda
Summary: Additive manufacturing (AM) allows faster and cheaper production of complex-shaped parts. Equal channel angular pressing (ECAP) induces strain and dislocations, leading to material strengthening. This study investigates the combination of directed energy deposition (DED) and ECAP processing on titanium alloy Ti-6Al-4V. The ECAP-processed specimens show significant improvement in mechanical properties.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Yulin Chen, Manping Liu, Lipeng Ding, Zhihong Jia, Shuangfeng Jia, Jianbo Wang, Maxim Murashkin, Ruslan Z. Valiev, Hans J. Roven
Summary: In this study, non-uniform Mg solute distribution (i.e., Mg-enriched/depletion zones) around grain boundaries (GBs) in a nanocrystalline Al-8 Mg alloy was observed through experimental observation. The abnormal segregation hindered GB migration and dislocation motion, thus enhancing the strength of the material. A proposed inhomogeneous solute distribution mechanism may contribute to the development of new strengthening mechanisms for nanocrystalline materials.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Physical
Elena V. Bobruk, Maxim Yu. Murashkin, Ilnar A. Ramazanov, Vil U. Kazykhanov, Ruslan Z. Valiev
Summary: This study aims to achieve superplasticity of ultrafine-grained (UFG) Al 2024 alloy at temperatures lower than traditional commercial Al alloys. Complex tensile tests were conducted at various temperatures and strain rates, and the UFG alloy exhibited superplastic behavior at 240 and 270 degrees C. The UFG alloy also demonstrated higher strength compared to the standard strengthening heat treatment T6.
Article
Materials Science, Multidisciplinary
G. Klevtsov, R. Z. Valiev, M. Fesenyuk, N. A. Klevtsova, M. N. Tyurkov, A. A. Matchin, E. Nosov
Summary: This paper investigates the mechanical properties of titanium Grade4, magnesium alloy Mg-Zn-Ca, and corrosion-resistant austenitic steel 08Kh18N9 for medical applications. The study compares the properties of coarse-grained (CG) and ultrafine-grained (UFG) materials produced by severe plastic deformation processing. It is found that the UFG materials have higher strength and lower sensitivity to cyclic overloads. Therefore, UFG materials show promise for the manufacture of medical devices.
LETTERS ON MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Andrew K. Hoffman, Yongfeng Zhang, Maalavan Arivu, Li He, Kumar Sridharan, Yaqiao Wu, Rinat K. Islamgaliev, Ruslan Z. Valiev, Haiming Wen
Summary: In nuclear reactor environments, nanocrystalline 304 stainless steel exhibits unique radiation-induced segregation behavior with the enrichment of Cr at grain boundaries. Lattice-based atomic kinetic Monte Carlo simulations reveal the influences of grain size, injected interstitials, and self-ion injection on grain boundary segregation.
Article
Mechanics
G. V. Klevtsov, L. R. Botvina, N. A. Klevtsova, R. Z. Valiev, I. N. Pigaleva
Summary: Fatigue failure is the most common type of failure in various engineering systems, and its study is crucial for predicting system's service life. The investigation of fatigue failure in new ultrafine-grained nanostructured metal materials is particularly interesting. This study demonstrates the possibility of determining the maximum cycle stress and cycle asymmetry coefficient from the depth of plastic zones beneath the surface of fatigue fractures.
PHYSICAL MESOMECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Gennadiy V. Klevtsov, Ruslan Z. Valiev, Natal'ya A. Klevtsova, Maksim N. Tyurkov, Irina N. Pigaleva, Denis A. Aksenov
Summary: This paper analyzes the fracture kinetics and mechanisms of different ultrafine-grained materials with different crystal lattices in the low-cycle fatigue region. The tests conducted show that the formation of ultrafine-grained structure has an unclear effect on the total number of cycles to failure of the samples. The fatigue crack initiation cycles account for about 20% of the total life of the samples, regardless of the material state and crystal lattice type. The fatigue crack propagation rates of the majority of investigated ultrafine-grained materials are close to or lower than that of the initial coarse-grained materials.
Article
Crystallography
Shivam Dangwal, Kaveh Edalati, Ruslan Z. Z. Valiev, Terence G. G. Langdon
Summary: Strengthening and softening mechanisms in ultrafine-grained materials have been debated for many years. This study examines the Hall-Petch relationship in ultrafine-grained magnesium, aluminum, copper, and iron. The results show that while the materials follow the Hall-Petch relationship initially, an up-break occurs for grain sizes below 500-1000 nm. This is due to enhanced dislocation contribution. However, a down-break occurs for grain sizes smaller than 70-150 nm due to diminished dislocation contribution and increased thermally-activated phenomena. The study also finds that strategies other than grain refinement, such as microstructural stabilization by segregation or precipitation, are necessary to achieve extra strengthening.
Article
Materials Science, Multidisciplinary
Roman R. Valiev, Alexey V. Panin, Emil I. Usmanov, Yana N. Savina, Ruslan Z. Valiev
Summary: This study demonstrates for the first time the influence of high-pressure torsion (HPT) on microstructural refinement and mechanical strength of Ti-6Al-4V titanium alloy produced by wire-feed electron-beam additive manufacturing. HPT processing results in an ultrafine-grained (UFG) structure and significantly increases the microhardness of the alloy. Microscopic studies reveal that the UFG structure consists predominantly of alpha and beta phases.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Physical
Anwar Qasim Ahmed, Daniel Olasz, Elena V. Bobruk, Ruslan Z. Valiev, Nguyen Q. Chinh
Summary: A supersaturated Al-Zn-Mg-Zr alloy with ultrafine-grained structure was obtained through the ECAP technique, resulting in significantly improved hardness and changes in subsequent thermal processes.
Article
Materials Science, Multidisciplinary
Olga Rybalchenko, Vladimir Torganchuk, Georgy Rybalchenko, Natalia Martynenko, Elena Lukyanova, Alexey Tokar, Dmitry Prosvirnin, Vladimir Yusupov, Sergey Dobatkin, Giovanni Meneghetti
Summary: This study examined the relationship between the microstructure and mechanical properties of Cr-Ni-Ti austenitic stainless steel through rotary swaging and annealing. The results showed that rotary swaging resulted in an ultrafine-grained structure, leading to increased ultimate tensile strength and fatigue limit. Annealing triggered the precipitation of nanosized TiC carbides in the deformed steel, stabilizing the properties of the steel.
Article
Materials Science, Biomaterials
Alexander A. Matchin, Evgeniy V. Nosov, Alexander A. Stadnikov, Gennadiy V. Klevtsov, Luiza R. Rezyapova, Natalia A. Sayapina, Elena V. Blinova, Ruslan Z. Valiev
Summary: This study focuses on the osseointegration behavior of medical implants made from nanostructured grade 4 titanium in maxillofacial surgery. The results show that nanotitanium implants have a significantly faster fixation rate due to osseointegration compared to standard factory-made implants, indicating better osseointegration for nanotitanium implants.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2023)
