Article
Materials Science, Multidisciplinary
S. Wei, H. Zhang, C. Tangpatjaroen, J. Tarnsangpradit, A. D. Usta, M. Eriten, J. H. Perepezko, I. Szlufarska
Summary: The study found wear-induced grain refinement in UFG aluminum, with the mean contact stress playing a key role in the transition between grain growth and refinement. Hardness was observed to increase with decreasing grain size, deviating from the Hall-Petch relation. Differences in dislocation contents among samples prepared by different methods contributed to variations in wear resistance.
Article
Materials Science, Composites
Yuming Xie, Xiangchen Meng, Yulong Li, Dongxin Mao, Long Wan, Yongxian Huang
Summary: Ultra-refined grains were achieved in aluminum matrix composites reinforced with few-layer graphene nanoplatelets through deformation-driven metallurgy under thermo-mechanical coupling, resulting in a significantly refined microstructure and high strengthening-toughening efficiency.
COMPOSITES COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Huizi Chen, Jian Wang, Xiangchen Meng, Yuming Xie, Yulong Li, Long Wan, Yongxian Huang
Summary: Utilizing friction stir processing, an ultrafine-grained structure was achieved in Mg-Zn-Y-Zr alloy leading to extraordinary superplasticity. Grain refinement and homogeneous dispersion of precipitates were promoted by the coupled thermo-mechanical effect, resulting in an ultra-fined grains size of 1.9 +/- 0.4 μm and a superplastic elongation of 642%. Grain boundary sliding was considered as the predominant superplastic deformation mechanism in ultrafine-grained materials.
Article
Nanoscience & Nanotechnology
Seyed Elias Mousavi, Ali Sonboli, Mahmood Meratian, Mohabbat Amirnejad, Seyed Hadi Mohamadi Azghandi, Paul Munroe
Summary: The study shows that low stacking fault energy alloys processed by ECAP can achieve unexpected mechanical properties, with high ductility reaching up to -80% while maintaining good tensile strength. The investigation of alloy microstructure reveals a combination of deformation mechanisms, including slip and twinning, accompanied by grain boundary serration and grain fragmentation. These deformation modes trigger the unexpected mechanical properties in this alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Manufacturing
Tianhao Wang, Bharat Gwalani, Miao Song, Xiaolong Ma, Tingkun Liu, Hrishikesh Das, Joshua Silverstein, Scott Whalen
Summary: Traditional riveting methods are not suitable for high-strength aluminum alloys, but rotating hammer riveting (RHR) can effectively solve this problem without the need for additional treatment on the rivets.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Review
Materials Science, Multidisciplinary
Zeinab Savaedi, Reza Motallebi, Hamed Mirzadeh, Rouhollah Mehdinavaz Aghdam, Reza Mahmudi
Summary: This overview article reviews the superplastic behavior of medical magnesium alloys. It discusses the basics of superplasticity and superplastic forming via grain boundary sliding (GBS). The properties of biomedical Mg alloys are tabulated. The critical discussion focuses on the superplasticity of biocompatible Mg-Al, Mg-Zn, Mg-Li, and Mg-RE alloys, emphasizing the influence of grain size, hot deformation temperature, and strain rate on tensile ductility.
CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE
(2023)
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
Abbas Mohammadi, Nariman A. Enikeev, Maxim Yu Murashkin, Makoto Arita, Kaveh Edalati
Summary: The study achieved nanograin sizes in an Al-La-Ce alloy through ultra-SPD followed by aging, and identified two breaks in the Hall-Petch relationship. Detailed analysis confirmed that nanograin formation alone is not sufficient for extra hardening, and additional strategies such as grain-boundary segregation and precipitation are necessary to address the issue of softening.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Metallurgy & Metallurgical Engineering
R. Bakhshi, M. H. Farshidi, S. A. Sajjadi
Summary: The study shows that a superior strengthening effect is achieved through the imposition of severe plastic deformation supplemented by post-deformation natural ageing. The yield strength of the alloy increases to over 400 MPa, which is about one-third higher than the value obtained after the usual T6 treatment. This superior strength is mainly attributed to grain refinement, increased dislocation density, and an increased volume fraction of precipitates during natural ageing.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Review
Materials Science, Multidisciplinary
Pavel Dolzhenko, Marina Tikhonova, Marina Odnobokova, Rustam Kaibyshev, Andrey Belyakov
Summary: The aim of this review is to summarize recent achievements in the development of ultrafine-grained austenitic/ferritic stainless steels through large strain deformation. The paper discusses various methods of large strain deformation for producing ultrafine-grained metallic materials. It also explores the structural mechanisms responsible for grain refinement during plastic deformation and examines the physical and mechanical properties of ultrafine-grained stainless steels. The review concludes that the development of ultrafine-grained microstructures during severe plastic deformation is a result of continuous dynamic recrystallization, with the misorientations among strain-induced cells/subgrains progressively increasing.
Article
Materials Science, Multidisciplinary
Zhao-Yuan Meng, Cheng Wang, Zhen-Ming Hua, Min Zha, Hui-Yuan Wang
Summary: Through achieving extraordinary fine-grain thermal stability under high-temperature solid-solution treatment, the dilute Mg alloy exhibits fine-grained structure and impressive mechanical properties, highlighting the importance of high-temperature solid-solution in developing high-strength alloys.
MATERIALS RESEARCH LETTERS
(2022)
Article
Metallurgy & Metallurgical Engineering
Oleg Sitdikov, Elena Avtokratova, Oksana Latypova, Michael Markushev
Summary: This study compared the structure and mechanical behavior of an Al-5Mg-0.18Mn-0.25c-0.08Zr-0.01Fe-0.01Si alloy under different deformation processes, showing that MIF resulted in ultrafine-grained structure and significantly enhanced strength and ductility after WR and CR. ECAP achieved more profound grain refinement but equal properties with MIF after WR, while CR following ECAP exhibited higher strengthening and slightly better superplastic behavior compared to MIF.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Materials Science, Multidisciplinary
Yang Zhou, Hansong Xue, Jianbo Peng, Haitao Pan, Wei Xie, Song Liu, Dingfei Zhang, Bin Jiang, Fusheng Pan
Summary: In this work, an Mg-8Zn-1Mn-3Sn-1.2Gd-0.2Dy alloy with excellent combination of tensile strength and ductility is successfully prepared. The formation mechanism of Dy-modified MgSnGd phase and its effect on the microstructure and mechanical properties of the alloy are systematically investigated. The addition of Dy promotes dynamic recrystallization and inhibits the growth of MgSnGd phase, resulting in the alloy exhibiting high strength and ductility.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
A. H. Boluri Gashti, B. Rozegari Ghashghay, H. R. Abedi
Summary: This study focuses on the hot deformation behavior of A356 aluminum alloy, particularly its flow softening capability. The results show that dynamic recrystallization dominates the deformation behavior at temperatures above 250°C, leading to a steady state stress level. In the semi-solid temperature range, the melting of eutectic silicon phase causes a sharp decrease in resistance against deformation, and the penetration of liquid phase along sub-boundaries results in grain partitioning, resembling the occurrence of dynamic recrystallization.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
F. Khodabakhshi, A. P. Gerlich, D. Verma, M. Nosko, M. Haghshenas
Summary: This paper investigates the small-scale plasticity of UFG alloy and NS materials under different temperature conditions through nanoindentation testing and modeling results. It analyzes the influence of the interaction between dislocations and nanoparticles on material flow behavior, and discusses the impact of nanoparticles on grain boundary diffusion and sliding mechanisms.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Vladimir Torganchuk, Igor Vysotskiy, Sergey Malopheyev, Andrey Belyakov, Rustam Kaibyshev
Summary: Friction stir welding was performed on an Fe-12%Mn-0.5%C-1.5%Al austenitic steel, resulting in fine grained microstructures in the stir zones. An increase in welding feed rate led to a decrease in mean grain size and an increase in dislocation density. A unique power law relationship between grain size and dislocation density was observed, enabling the prediction of yield strength exceeding 500 MPa.
PHILOSOPHICAL MAGAZINE
(2021)
Article
Materials Science, Multidisciplinary
Alexander Kalinenko, Igor Vysotskiy, Sergey Malopheyev, Sergey Mironov, Rustam Kaibyshev
Summary: This study investigates the relationship between thermal cycle generated during friction-stir welding of a 6061 aluminum alloy and resulting grain structure evolution. The grain structure evolution is mainly controlled by continuous recrystallization, while at elevated temperatures, competitive recovery hinders recrystallization kinetics.
MATERIALS CHARACTERIZATION
(2021)
Article
Nanoscience & Nanotechnology
Alexander Kalinenko, Igor Vysotskii, Sergey Malopheyev, Sergey Mironov, Rustam Kaibyshev
Summary: The relationship between welding conditions, annealing behavior, and mechanical performance of friction-stir welded 6061-T6 aluminum alloy was examined in this study. It was found that the welded material was unstable against abnormal grain growth during post-weld solutionizing treatment, with a lowering of FSW heat input inhibiting this phenomenon. Abnormal grain growth was observed to lead to a rotation of the original crystallographic texture, and may be governed by the orientation-growth mechanism.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Alexander Kalinenko, Igor Vysotskiy, Sergey Malopheyev, Marat Gazizov, Sergey Mironov, Rustam Kaibyshev
Summary: This study emphasizes that the pre-straining approach is not efficient in suppressing abnormal grain growth in friction-stir welds produced under low-heat-input conditions, as the introduced dislocation density is insufficient to overcome grain-boundary energy. Subsequent annealing behavior is mainly governed by grain growth rather than recrystallization.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
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
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
Materials Science, Multidisciplinary
Ivan S. Zuiko, Sergey Malopheyev, Sergey Mironov, Sergey Betsofen, Rustam Kaibyshev
Summary: The macro-scale distribution of secondary precipitates in friction-stir-welded 2519 aluminium alloy was found to vary within the stir zone due to local variations in welding temperature and cooling rate. Precipitation coarsening was most pronounced at the weld root, while dissolution was enhanced at the upper weld surface. Reprecipitation phenomena were most prominent in the weld nugget.
Article
Materials Science, Multidisciplinary
Igor Vysotskiy, Sergey Malopheyev, Ivan Zuiko, Sergey Mironov, Rustam Kaibyshev
Summary: In this study, EBSD was used to investigate the microstructure distribution within the selective-laser-melted 17-4 PH martensitic steel. The volume fraction of delta-ferrite decreased in the building direction, which was attributed to a decrease in cooling rate and promoted the delta-ferrite -> austenite -> alpha-martensite transformation sequence.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Igor Vysotskiy, Sergey Malopheyev, Ivan Zuiko, Sergey Mironov, Rustam Kaibyshev
Summary: This study focuses on the crystallographic aspects of laser-powder bed fusion of 17-4 PH martensitic steel. The crystallization process showed an epitaxial mechanism and resulted in a specific crystal structure relationship between ferrite and austenite. Grain-boundary austenite was found to have a relationship with adjacent ferrite grains. The phase transformation from austenite to martensite did not exhibit significant variant selection.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Alexander Kalinenko, Vasiliy Mishin, Ivan Shishov, Sergey Malopheyev, Ivan Zuiko, Vseslav Novikov, Sergey Mironov, Rustam Kaibyshev, Sheldon Lee Semiatin
Summary: The relationship between the temperature conditions during friction-stir welding, the stir-zone microstructure, and the thermal stability of welded aluminum-alloy 6061 joints was investigated. It was found that the stir-zone microstructure was unstable against abnormal grain growth during post-weld solution annealing. The abnormal grain growth developed rapidly, nearly completing during the heating process. Annealing behavior followed Humphrey's cellular-growth model in all welded conditions. Low-heat-input led to a competition between normal grain growth and abnormal grain growth, resulting in relatively small final grain size. High-heat-input conditions provided microstructural stability but triggered catastrophic grain coarsening. Remarkably, abnormal grain growth led to a rotation of the crystallographic texture in the stir zone.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Physical
Alexander Kalinenko, Pavel Dolzhenko, Yulia Borisova, Sergey Malopheyev, Sergey Mironov, Rustam Kaibyshev
Summary: An approach to optimize dissimilar friction stir lap welding of aluminum and titanium alloys was proposed. The technique involved plunging the welding tool into the aluminum part only and welding at a high-heat input condition, resulting in sound welds and a narrow intermetallic layer. However, it caused microstructural changes and material softening in the aluminum part, and was not feasible in highly alloyed aluminum alloys.
Article
Chemistry, Physical
Ivan S. Zuiko, Sergey Malopheyev, Sergey Mironov, Rustam Kaibyshev
Summary: In this study, the friction-stir welding technique was successfully applied to join AA2519 to AA5181 alloy, and the microstructure and mechanical properties of the dissimilar FSW joints were investigated. The welded joints showed high ultimate tensile strength and good ductility, with microhardness values at the stir zone higher than the base material AA5182, demonstrating nearly 100% joint efficiency based on AA5182.
Article
Chemistry, Physical
Sergey S. Malopheyev, Ivan S. Zuiko, Sergey Yu. Mironov, Rustam O. Kaibyshev
Summary: The purpose of this study was to examine the microstructural evolution during the fabrication of an Al/Al2O3 composite using friction stir processing (FSP). Advanced characterization techniques were applied to a longitudinal section of the composite, revealing that the reinforcing particles quickly rearranged into a stable onion-ring structure, which persisted even after 12 FSP passes. It was concluded that the typical three to four FSP passes used in practice are insufficient for achieving a homogeneous dispersion of the reinforcing particles. Furthermore, the gradual distribution of nanoscale Al2O3 particles in the aluminum matrix resulted in a slight reduction in high-angle boundaries and average grain size, attributed to particle pinning of grain-boundary migration and dislocation slip.
Article
Materials Science, Multidisciplinary
Ivan S. Zuiko, Sergey Malopheyev, Salaheddin Rahimi, Sergey Mironov, Rustam Kaibyshev
Summary: This study investigates the early stages of abnormal grain growth (AGG) in a friction-stir-welded 2519-T820 aluminium alloy. Microstructural evolutions during the heating stage of a solution heat treatment (SHT) were studied. The study found that the welded materials underwent a complex sequence of precipitation phenomena, which eventually led to AGG. The evolution of precipitates was heavily dependent on the FSW temperature condition.
Article
Engineering, Manufacturing
Vasiliy Mishin, Ivan Shishov, Alexander Kalinenko, Igor Vysotskii, Ivan Zuiko, Sergey Malopheyev, Sergey Mironov, Rustam Kaibyshev
Summary: A finite-element model was developed to simulate the thermomechanical behavior of 6061 aluminum alloy during friction-stir welding (FSW). The study revealed that FSW-induced deformation is a two-stage process, with both the rotating tool probe and the shoulder edge affecting the material. The effects of tool rotation and translation rates on FSW temperature and strain were also examined.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2022)
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.
