Article
Metallurgy & Metallurgical Engineering
Hyun Ji Kim, Ye Jin Kim, Sung Hyuk Park
Summary: The study investigates the effects of pre-existing {10-12} extension twins on the precipitation behavior and mechanical properties of aged AZ80 material. The material with {10-12} twins exhibits a finer grain size and higher dislocation density compared to the extruded material. The presence of {10-12} twins promotes continuous precipitation and suppresses the formation of coarse precipitates at grain boundaries, resulting in improved tensile strength and elongation.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Materials Science, Multidisciplinary
Shou-Peng Xu, Chun-Sheng Shi, Nai-Qin Zhao, Chun-Nian He
Summary: The study systematically analyzed the microstructure and tensile properties of A356-0.13Ti alloys with different contents of scandium and scandium/zirconium after solution and aging treatment process. The addition of Sc/Zr greatly refined the grain size, modified deleterious structures, and significantly enhanced the tensile properties of the A356 alloy.
Article
Metallurgy & Metallurgical Engineering
Hyun Ji Kim, Sumi Jo, Sung Hyuk Park
Summary: This study investigates the effect of {10-12} deformation twins on the continuous precipitation behavior of an extruded Mg-8.0Al-0.5Zn-0.2Mn (AZ80) alloy during aging. The introduction of {10-12} twins accelerates the static precipitation of CPs and improves the tensile properties of the peak-aged material in the extruded AZ80 alloy. Pre-twinned material exhibits significantly shorter peak-aging time, smaller and more densely distributed CPs, and higher tensile strength and ductility compared to the extruded material.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Chemistry, Physical
Hui Zhao, Lingying Ye, Quanshi Cheng, Yuan Kang, Wenjing Zhang
Summary: The effect of variable-rate non-isothermal aging (VR-NIA) on the properties of 7055 aluminum alloy was investigated. A four-stage VR-NIA process was proposed and applied to obtain a good combination of mechanical properties and corrosion resistance in a relatively short time. The changes in microstructure and grain boundary precipitates (GBPs) during the VR-NIA process were analyzed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Zhi-Jun Zhao, Xin-Fu Gu, Meng Li, Ming-Le You, Mohan Chen, Fu-Zhi Dai, Zhang-Zhi Shi
Summary: A nano-precipitate of Si-Mg2Si core-shell structure is discovered in Al alloys for the first time. The orientation relationship between the ss-Mg2Si shell and the Si core is predicted by a near row matching model based on interfacial good matching. First-principles calculation reveals that heterogeneous nucleation of Mg2Si on Si is favored due to reduction of nucleation barrier.
Article
Materials Science, Multidisciplinary
Hyeon-Woo Son, Sang-Hwa Lee, Sung-Ho Kang, Yong-You Kim, Kwangjun Euh
Summary: The effect of Ge addition on the delaying natural aging of Al-Mg-Si-Cu alloy was investigated. It was found that Ge addition suppressed the natural aging kinetics and cluster size. Atom probe tomography revealed that Ge refinement of cluster evolution was achieved by disturbing the magnesium enrichment of silicon-silicon clusters and enhancing vacancy trapping. Ge segregation at the cluster interface was also considered as a potential barrier to cluster growth.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Haitao Jiang, Hui Xing, Zihan Xu, Bing Yang, Weijun Feng, Tan Sui, Yanfeng Han, Jiao Zhang, Sun Baode
Summary: Hot-forming Quenching (HFQ) can significantly alter the microstructure of high-strength aluminum alloys for car body sheet and achieve desired performance through effective control. Three designed processes, HFQ + Natural Aging (NA) + Simulate Baking (SB), HFQ + Pre-aging (PA) + SB and HFQ + Peak-aging (T6), were systematically studied using HRTEM-SAED to understand the evolution of precipitated phases. The results showed that HFQ + PA + SB had high-density and finely distributed eta' phases, with small and discontinuously distributed grain boundary precipitates. Adjusting the pre-aging temperature and time provided ample nucleation sites for precipitation during the baking stage, ensuring the formation of eta' phases with high quantity density. The end product exhibited a tensile strength of 660.1 MPa and a yield strength of 639.4 MPa, making it a promising material for future car body applications.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Gyo Myeong Lee, Jong Un Lee, Sung Hyuk Park
Summary: This study investigates the effects of post-heat treatments on microstructural characteristics, uniaxial tensile properties, and three-point bending properties of an extruded AZ80 alloy. Different heat treatments result in variations in the material's performance, mainly due to differences in grain size and precipitate amount.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
Yelin Zhang, Hongfu Yang, Peng Sun, Rensong Huang, Shanju Zheng, Yonghua Duan, Mengnie Li
Summary: The influence of solid solution and single-stage aging treatment on the microstructure and properties of 7075 aluminum alloy was investigated. The study found that the microstructure of the alloy in different treatment states exhibited strip structures. The solid solution treatment process resulted in the resolution of fine second phases into the α-Al matrix, with higher temperatures leading to less precipitation phase in the α-Al matrix. Aging treatment caused the precipitation of many fine second phases in the α-Al matrix and grain boundary, distributed uniformly along the rolling direction. The study also established precipitation kinetics equations for the alloy under different aging treatments.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Multidisciplinary
Dongsheng Xie, Hucheng Pan, Zhen Pan, Tong Fu, Zhuoran Zeng, Hongbo Xie, Yuping Ren, Weineng Tang, Gaowu Qin
Summary: By using the appropriate extrusion process, a new Mg-Sm-Ce-Mn-based alloying system with a large miscibility gap achieved multi-solute co-segregations at high-angular grain boundaries, dislocations, and low-angular grain boundaries. The solute along high-angular grain boundaries gradually evolved into nano-precipitates during long-term thermal exposure, while the precipitation process along low-angular grain boundaries was significantly suppressed. Numerous G.P. zones and gamma phases formed in deformed regions, maintaining limited size and reticular distribution. As a result, the bimodal-grain structure exhibited thermal stability and the excellent high-temperature strength was well-maintained.
MATERIALS RESEARCH LETTERS
(2023)
Article
Metallurgy & Metallurgical Engineering
Gao Chuan, Deng Yunlai, Wang Fengquan, Guo Xiaobin
Summary: The effect of creep aging on the mechanical properties of under-aged 7075 alloy was studied. Creep aging greatly improves the plasticity of the under-aged 7075 aluminum alloy while maintaining its high strength. The mechanical properties of the alloy are sensitive to creep stress. The size and volume fraction of precipitates increase with increasing creep aging time.
ACTA METALLURGICA SINICA
(2022)
Article
Engineering, Manufacturing
Sumit Bahl, Alex Plotkowski, Thomas R. Watkins, Richard A. Michi, Benjamin Stump, Donovan N. Leonard, Jonathan D. Poplawsky, Ryan Dehoff, Amit Shyam
Summary: Additive manufacturing (AM) allows for the printing of structures with site-specific properties. In this study, a simple approach utilizing eutectic solidification characteristics is demonstrated to achieve site-specific properties in an Al-Cu-Ce-Zr alloy using laser powder bed fusion AM. The yield strength of the alloy can be tuned by adjusting the laser scan speed and hatch spacing, with faster speeds resulting in finer eutectic spacing and higher strength. The relationship between scan speed, eutectic spacing, and strength is successfully applied to print a complex pattern of site-specific hardness in the alloy, showcasing the potential of using AM for creating site-specific properties and anisotropy in alloys.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Huilong Zhong, Shengci Li, Jiali Wu, Hongling Deng, Jiqiang Chen, Na Yan, Zixin Chen, Liangbo Duan
Summary: The study investigates the effects of different RRA treatments on the microstructure, mechanical properties, and corrosion resistance of a Zr + Er modified Al-Zn-Mg-Cu alloy. It is found that controlling the regression time and temperature can regulate the characteristics of precipitated phases, leading to an optimal balance of mechanical properties and corrosion resistance.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Physical
Hasan Vafaeenezhad, Hamid Reza Shahverdi
Summary: This study investigates the impact of incorporating different amounts of V into an Al-0.06Sc-0.06Zr-0.18Si at% alloy on the behavior of nanoprecipitates and the creep resistance of the alloy. The findings show that the amount of V added affects the structure, kinetics, coarsening resistance, and creep resistance of the alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
C. Menapace, F. Bernard, M. Lusa, G. Ischia, G. Straffelini
Summary: Research has shown that using dual step and dual rate ageing (DRA) cycles can significantly improve the mechanical properties of 6060 Al alloy, characterized by fine precipitation particles. Additionally, the number and size of precipitates also influence the strain hardening and fracture behavior of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Composites
Jinmei Chen, Xiaosong Jiang, Lan Lyu, Yanjun Li, Pal Christian, Hongliang Sun, Rui Shu
Summary: In this study, Al-Si matrix composites reinforced with in-situ Al2O3, C nanotubes (CNTs), and graphene nanoplatelets (GNPs) were successfully prepared using ball milling, hot-isostatic pressing (HIP), and subsequent high-pressure torsion (HPT). The microstructures were significantly refined and reinforcements well dispersed in the matrix by HPT. With an increase in the number of HPT cycles, both microhardness and electrical conductivity of the composites increased, mainly attributed to fine-grain strengthening.
COMPOSITE INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Bijin Zhou, Leyun Wang, Jinhui Wang, Alireza Maldar, Gaoming Zhu, Hailong Jia, Peipeng Jin, Xiaoqin Zeng, Yanjun Li
Summary: The dislocation behavior of Mg-5Y alloy during tensile deformation was quantitatively studied using in-situ tensile test, VPSC modeling, and TEM. Results showed that <a> dislocations were the primary contributors to deformation, with a small fraction of <c+a> dislocations activated near grain boundaries. The alloy exhibited a lower CRSS ratio and high ductility, attributed to the mobility of <c+a> dislocations.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Feng Qian, Shenbao Jin, Di Wan, Wenzhe Li, Xingwang Cheng, Gang Sha, Yanjun Li
Summary: By making minor additions of Cd and Cr, as well as increasing Si content, the modified AA3003 alloy shows a 39% increase in yield strength compared to the base alloy under the same heat treatment. The thermal stability of the modified alloy is greatly improved when exposed to long-term high temperature conditions, leading to better dispersion strengthening and promising mechanical properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Jiahui Dong, Nong Gao, Ying Chen, Lingfei Cao, Hui Song, Hannes Froeck, Benjamin Milkereit, Marco J. Starink
Summary: The combined effects of high pressure torsion and age hardening were investigated on a 3rd generation Al-Cu-Li alloy. The results showed that the novel multi-stage processes significantly improved the hardness of the alloy and refined its microstructure.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Jiawei Yang, Yijiang Xu, Sarina Bao, Shahid Akhtar, Ulf Tundal, Stig Tjotta, Yanjun Li
Summary: This study investigates the influence of inclusions and filtration on the grain refinement effect of AA 6060 alloy. The results show that both inclusions and filtration significantly reduce the grain refinement efficiency of the grain refiner master alloys. A grain size prediction model is applied to estimate the loss of effective grain refiner particles during filtration.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Aina Opsal Bakke, Arne Nordmark, Lars Arnberg, Yanjun Li
Summary: A novel coating method, hot dipping of Sn, has been developed to achieve continuous metallurgical bonding between A356 aluminum and steel, improving wettability and promoting strong adhesion between the two materials. Detailed analysis of intermetallic structures at the interface reveals the effectiveness of the Sn-coating in enhancing the bonding performance.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2022)
Article
Multidisciplinary Sciences
Shenghua Wu, Hanne S. Soreide, Bin Chen, Jianjun Bian, Chong Yang, Chunan Li, Peng Zhang, Pengming Cheng, Jinyu Zhang, Yong Peng, Gang Liu, Yanjun Li, Hans J. Roven, Jun Sun
Summary: A counterintuitive strategy of stabilizing supersaturated solid solution in nanograined Al-Cu alloys using high-density vacancies and Sc microalloying is reported. The combination generates a higher concentration of vacancies bonded in strong atomic complexes, achieving high thermal stability and improved mechanical properties.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Zixuan Wu, Xiaosong Jiang, Yanjun Li, Pal Christian, Hongliang Sun, Yali Zhang, Yongjian Fang, Rui Shu
Summary: In this study, graphene nanoplatelets (GNPs) reinforced Cu/Ti3SiC2/C nanocomposites were successfully prepared by high-pressure torsion (HPT) after powder metallurgy. The study systematically analyzed the microstructures, interfacial bonding, mechanical, and electrical properties of the nanocomposites. The results showed that HPT significantly improved the dispersion of GNPs, the clarity and bonding of interfaces between the matrix and reinforcing phases. The grain size of the nanocomposites was considerably refined. The study also found that with the increase of HPT turns, the relative density, mechanical, and electrical properties of the nanocomposites were all improved.
MATERIALS CHARACTERIZATION
(2022)
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
Materials Science, Multidisciplinary
Odd M. Akselsen, Ruben Bjorge, Hakon Wiik anes, Xiaobo Ren, Bard Nyhus
Summary: In this study, wire arc additive manufacturing of Inconel 625 was conducted using the cold metal transfer technique, revealing an increase in hardness with different regions and the formation of particle types through microstructure examination.
Article
Materials Science, Multidisciplinary
Ning Ma, Dongdong Zhao, Chunsheng Shi, Chunnian He, Enzuo Liu, Junwei Sha, Yanjun Li, Naiqin Zhao
Summary: Mg segregation at grain boundaries in nanocrystalline Al alloys contributes to additional strengthening and improved stability of the grain boundaries. The segregation increases the critical stress for dislocation nucleation, leading to an increase in the tensile strength of the grain boundaries.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Siqi Liu, Di Wan, Ding Peng, Xu Lu, Xiaobo Ren, Yuequn Fu, Feng Wang, Yanjun Li, Zhiliang Zhang, Jianying He
Summary: This study investigated the effect of heat input on hardness and strain rate sensitivity (SRS) by studying wire-arc additive manufactured (WAAM) Al 4047 alloys produced under different heat inputs. The research found that nanohardness decreased with increasing heat input due to enhanced solid solution strengthening produced by lower heat input.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Christoph Martin Hell, Hanne-Sofie Soreide, Ruben Bjorge, Calin Daniel Marioara, Yanjun Li, Randi Holmestad
Summary: This study analyzed the effects of ramping up to artificial aging (AA) temperature in combination with natural aging (NA) on two different industrial aluminium alloys. The findings suggest that NA prior to AA reduces the strength of the alloys regardless of ramping. However, for the alloy with a high copper (Cu) content, a clear increase in peak hardness was observed when ramped from the supersaturated solid solution (SSSS). The length of the peak strength plateau is shorter for ramped samples, regardless of the NA time. Microscopy investigations revealed longer but fewer precipitates when ramped from the SSSS, and an increased precipitate number density when ramped after NA. The presence of fewer hybrid-type and overaged precipitates and more L/C was observed for all ramped conditions. Atom probe tomography measurements showed that more solute is left in the matrix between the precipitates when ramped directly from the SSSS, which is related to a lower precipitate number density.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Mechanical
Jianbin Xu, Odd Sture Hopperstad, Bjorn Holmedal, Torodd Berstad, Tomas Manik, Knut Marthinsen
Summary: The Portevin-Le Chatelier (PLC) effect and its spatio-temporal characteristics are studied in the aluminium alloy AA5182. Experimental and numerical methods are used to observe the nucleation and propagation of the PLC bands under different strain rates. The strain accumulation and strain ageing processes are found to determine the subsequent band nucleation.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
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.
