Article
Materials Science, Multidisciplinary
Chaomin Zhang, Yong Jiang, Yanjun Zhou, Xiuhua Guo, Kexing Song
Summary: Interface structure modeling and first-principles calculations were performed to investigate the segregation behaviors of Zr micro-alloying element at nano-Cr particle interfaces and low-Sigma Cu grain boundaries in CueCreZr alloys. The results showed that Zr can substitute Cu atoms at nano-Cr interfaces with the Nishiyama-Wassermann orientation relation, but not at interfaces with the Kurdjumove-Sachs orientation relation. Zr segregation at low-Sigma grain boundaries greatly improved the binding strength.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
G. Y. Li, Y. Q. Wang, J. D. Zuo, M. Zhang, C. He, X. Feng, J. H. Luan, Y. Lu, J. Y. Zhang, S. Cazottes, D. Kiener, G. Liu, J. Sun
Summary: The addition of Zr has a significant influence on the twin morphology and strengthening response of nanostructured Al films, with a higher Zr content resulting in Zr segregation at grain boundaries. The hardness of the films shows a strong Zr dependence, with the Al-13.4 at.% Zr film exhibiting a hardness about 11 times greater than pure Al due to the presence of 9R phase and solid solution strengthening.
Article
Materials Science, Multidisciplinary
Xuefeng Lu, Wei Zhang, Junqiang Ren, Qing Gao, Hongtao Xue, Fuling Tang, Peiqing La, Xin Guo
Summary: Grain boundary movement is closely related to plastic deformation of materials. In this study, the introduction of carbon atoms formed a highly stable carbon chain network, which greatly enhanced the stability of the grain boundaries and showed strong dislocation pinning capability. The results revealed that an appropriate amount of carbon content increased the yield strength and tensile strength, while excessive carbon content inhibited the generation of dislocations and resulted in a decline in the mechanical properties of the alloy. This research provides a new strategy for grain boundary engineering by introducing non-metallic atoms.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Cheng-Da Wu, He-Xing Li
Summary: The molecular dynamics simulations show that the potential energy of Cu-Zr systems significantly decreases with increasing Zr concentration, leading to enhanced structural stabilization. Additionally, doping Zr atoms at the grain boundaries can strengthen the boundaries and decrease their mobility during the tensile test. Moreover, the Young's modulus of Cu-Zr systems decreases with increasing Zr concentration, while the plasticity of Cu-Zr systems increases.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Shuo Wang, Xiang Cai, Zan Wang, Jia Ju, Jian Zhou, Feng Xue
Summary: This study investigates the impact of solute Al on the penetration of Cu atoms into the Fe grain boundary in the Fe-Cu embrittlement system through molecular dynamics simulations. Additionally, first principle density functional theory calculations are performed to determine the binding properties and electronic structure of GBs doped with solute atoms. The mechanisms of inhibiting liquid metal embrittlement cracks in the Fe-Cu system by Al are analyzed at the atomic scale. The results demonstrate that Al diffusion along the GB direction is much higher than that of Cu, and the preferential penetration and segregation of Al atoms act as a barrier layer.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
H. Z. Zhao, Z. S. You, N. R. Tao, L. Lu
Summary: The study found that the strengthening effect of nanotwins in heterogeneous nanostructure is not only dependent on the strength of themselves, but also influenced by the deformation compatibility with surrounding components. Orientation-dependent deformation compatibility was attributed to the interactions between isotropic shear bands in nanograin matrix and anisotropic deformation in nanotwin bundles.
Article
Chemistry, Physical
Liangyu Li, Jiawei Tang, Zhengqin Liu, Yiren Wang, Yong Jiang, Gang Sha
Summary: The micro-alloying effects of Ni on the microstructure evolution and mechanical properties of an Al-Zn-Mg-Cu-Sc-Zr alloy were thoroughly investigated using electron/atom microscopic characterization and first-principles calculations. A trace addition of 0.2 wt% Ni can induce a new primary phase of Al3(Ni, Cu) and refine the grain size to 23 μm. It was found that Ni promotes the precipitation of the eta phase, improves its thermal stability, and enhances the GB binding by segregating to Al GBs. The Ni micro-alloyed Al-Zn-Mg-Cu-Sc-Zr alloys exhibit high strength and thermal stability with acceptable plasticity, even with a low Cu/Mg atomic ratio (approximately 0.22), compared to most 7055 Al alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Xiaoying Qian, Yuyang Gao, Zhihua Dong, Bin Jiang, Chao He, Cuihong Wang, Ang Zhang, Baoqing Yang, Changyong Zheng, Fusheng Pan
Summary: The micro addition of Ca effectively increases the strength and ductility of Mg-Zn-Ce alloy by enhancing alloying segregation at grain boundary. The addition of Ca leads to enhanced Zn segregation and co-segregation of Zn, Ce, and Ca. This is attributed to the decreased segregation energy and promoted diffusion process of Zn by Ca, which accelerates the thermodynamic and kinetic process of segregation. The controllable segregation at grain boundary, induced by Ca, contributes to the development of advanced magnesium alloys by stabilizing grain boundary, refining grain size, inhibiting dislocation mobility, improving strength, and enhancing grain boundary cohesion and ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Alexey Rodin, Ainur Khairullin
Summary: The peculiarities of Ni and Fe diffusion in polycrystalline Cu and Cu-Fe alloys at a temperature range of 650-750 degrees C were studied. The obtained values of the Ni GB diffusion triple product were an order of magnitude less than the values obtained by the radiotracer method. The significant supersaturation of the Cu-based solid solution near the Fe/Cu interface was confirmed as a peculiarity of Fe diffusion.
Article
Materials Science, Multidisciplinary
Bailing An, Rongmei Niu, Yan Xin, William L. Starch, Zhaolong Xiang, Yifeng Su, Robert E. Goddard, Jun Lu, Theo M. Siegrist, Engang Wang, Ke Han
Summary: The addition of Sc in Cu-6 wt%Ag alloy suppresses discontinuous precipitation and enhances continuous precipitation, resulting in increased strength and slightly decreased electrical conductivity. Sc inhibits the nucleation of discontinuous precipitates and forms a thin intermetallic compound layer. After deformation, both discontinuous and continuous precipitates form Ag fibers, and the combination of deformation strain and doping leads to increased fiber density and decreased diameter, resulting in increased strength.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Hang Lv, Xinxin Gao, Kan Zhang, Mao Wen, Xingjia He, Zhongzhen Wu, Chang Liu, Changfeng Chen, Weitao Zheng
Summary: Achieving strength and toughness synergy through microstructure design is challenging in materials science. In this study, the authors develop a bamboo-like dual-phase copper-boron structure that simultaneously increases hardness, strength, and ductility. By using grain boundary engineering, the composition and bonding structure of neighboring crystallites can be tuned to strengthen materials, especially those composed of small nanograins. The findings suggest that constructing dual-phase nanocomposites with metal nanograins embedded in a strong and confining light-element grain boundary framework can be a new avenue for strengthening metals.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Eve-Audrey Picard, Frederic Sansoz
Summary: This study investigated the solute segregation phenomena in nanocrystalline alloys and identified various segregation configurations in different alloys, including heterogeneous segregation and homogeneous segregation. The findings highlight the significant impact of solute interactions on segregation and mechanical behavior.
Article
Nanoscience & Nanotechnology
Hiromi Miura, Chihiro Watanabe, Yoshiteru Aoyagi, Yojiro Oba, Masakazu Kobayashi, Naoki Yoshinaga
Summary: A stable SUS316LN austenitic stainless steel was cold-rolled to 92% reduction to form a complicated heterogeneous nanostructure. The material showed high tensile strength along the transverse direction, and peak aging further increased the strength. Grain-boundary segregation and the nano-lamellar structure contributed to the high strengthening effect.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Sang -Ho Oh, Yang-Jin Jeong, Sin-Hye Na, Jiman Kim, Alireza Zargaran, Byeong-Joo Lee
Summary: Atomic simulations and experimental observations were conducted to investigate the atomic details of the significant increase in the diffusional growth rate of A15 Nb3Sn superconducting compound with Ti addition. It was found that Ti atoms preferentially locate at Nb sites in the bulk compound and do not significantly affect the volume diffusion of Sn. Grain refinement was observed when Ti was added, which was expected to promote the effective diffusion of Sn. The main mechanism underlying the alloying effect of Ti was revealed to be grain boundary segregation and refinement. Understanding the atomic behavior of alloying elements in Nb3Sn and their effects on the diffusional growth is important for further investigation of optimal alloying strategies.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Mohammed Kamran Bhat, Prithiv Thoudden Sukumar, Lena Langenohl, James P. Best, Gerhard Dehm
Summary: Micropillar compression was used to study the effect of Ag segregation on the strength of a sigma 5 grain boundary in a copper bicrystal. Atom probe tomography analysis confirmed the presence of Ag segregation at the grain boundary. Micropillars containing Ag-segregated sigma 5 grain boundary showed higher yield strength than those without Ag segregation. Electron microscopy analysis revealed the difference in slip transmission mechanisms between Ag-free and Ag-containing bicrystals.
Article
Materials Science, Multidisciplinary
Y. H. Gao, P. F. Guan, R. Su, H. W. Chen, C. Yang, C. He, L. F. Cao, H. Song, J. Y. Zhang, X. F. Zhang, G. Liu, J. F. Nie, J. Sun, E. Ma
MATERIALS RESEARCH LETTERS
(2020)
Article
Materials Science, Multidisciplinary
Peng Zhang, Kunkun Shi, Jianjun Bian, Jinyu Zhang, Yong Peng, Gang Liu, Alexis Deschamps, Jun Sun
Summary: The study investigates the effects of solute clusters on the mechanical properties of a commercial Al-Zn-Mg alloy during natural aging (NA). It is found that dense solute clusters enhance the yield strength and strain hardening ability of the alloy without affecting dislocation density evolution. Solute clusters undergo a dissolution-to-coarsening transition during deformation, potentially contributing to the high strain hardening rate observed.
Article
Materials Science, Multidisciplinary
Shan Jiang, Lujun Huang, Xiang Gao, Gang Liu, Rui Zhang, Yang Jiao, Shang Peng, Qi An, Shuai Wang, Lin Geng
Summary: An interstitial carbon induced-FCC-Ti phase was observed in a carbon-doped complex concentrated alloy, and its crystal structure was characterized using Cs-corrected STEM. The FCC-Ti showed high nano hardness, elastic modulus, and ultrahigh strengths, potentially opening up new possibilities for future material design. These findings provide valuable insights into the role of interstitial atoms in alloy systems.
Article
Nanoscience & Nanotechnology
Y. H. Gao, L. F. Cao, J. Kuang, H. Song, G. Liu, J. Y. Zhang, J. Sun
Summary: This study conducted triple microalloying in an Al-Cu alloy, utilizing the interactions among Sc-Fe-Si elements to adjust the microstructural design of dual precipitates, enabling satisfactory dispersion and outstanding thermal stability of the dual precipitates in the current system, thus leading to good creep resistance at a high homologous temperature.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
S. H. Wu, H. Xue, C. Yang, P. M. Cheng, P. Zhang, J. Kuang, J. Y. Zhang, G. Liu, J. Sun
Summary: The study revealed a significant impact of silicon addition on the precipitation kinetics of Al-0.2wt%Zr-0.05wt%Sc alloys and the heterogeneous precipitation of Al-3(Sc, Zr) nanoparticles, while showing minor effects on peak-aging temperature and microhardness during isochronal aging.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
H. Xue, C. Yang, J. Kuang, P. Zhang, J. Y. Zhang, G. Liu, J. Sun
Summary: The study compared single and dual precipitation phenomena in different alloys, finding that Al3Sc precipitation was completely suppressed at 723K in the Al-2.4 wt% Cu-0.1 wt% Sc alloy, but unexpectedly promoted at 573K. Moreover, significant Sc-dependence of theta' precipitation was observed in the Al-Cu-Sc alloy at 573K, with a high aspect ratio of >200 for the theta' precipitates.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
S. H. Wu, H. Xue, C. Yang, J. Kuang, P. Zhang, J. Y. Zhang, Y. J. Li, Hans J. Roven, G. Liu, J. Sun
Summary: Experimental evidence show that equal channel angular pressing (ECAP) at cryogenic temperature enhances the strength-ductility synergy of Al-2.5wt.%Cu alloy, mainly due to the microstructural control and intra-granular precipitation. Adding a minor amount of 0.3wt.% Sc can optimize the precipitation and further boost the strength and ductility of the alloy.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
D. D. Zhang, J. Y. Zhang, J. Kuang, G. Liu, J. Sun
Summary: A novel (NiCoCr)(92)Al6Ta2 medium-entropy alloy was developed with superior cryogenic mechanical properties, showing temperature-dependent mechanical behavior and excellent strength-ductility synergy. The alloy exhibits extraordinary strain hardening capacity and temperature-dependent deformation mechanisms, resulting in enhanced ductility at low temperatures.
Article
Engineering, Mechanical
J. F. Xiao, X. K. Shang, J. H. Hou, Y. Li, B. B. He
Summary: This study investigates the damage behavior of a typical model metastable Ti-1023 alloy with dominant stress-induced martensite (SIM). The results show that SIM has a dual impact on the damage behavior of the alloy, either facilitating crack nucleation or inhibiting crack propagation depending on the martensitic lath spacing. Additionally, the effect of beta stability on the damage behavior is indirectly determined by the martensitic lath spacing, suggesting that grain boundary engineering should be utilized to fully explore the potential of SIM in developing strong and ductile/tough Ti alloys for broad industrial applications.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Nanoscience & Nanotechnology
J. D. Zuo, Y. Q. Wang, K. Wu, J. Y. Zhang, G. Liu, J. Sun
Summary: In this study, a templated growth strategy by introducing a Cr buffer layer is proposed to tailor the phase composition in Ta films. The beta-Ta/alpha-Ta ratio in the films can be continuously and precisely controlled by adjusting the thickness of the buffer layer, resulting in different hardness of the Ta films.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
D. D. Zhang, J. Y. Zhang, J. Kuang, G. Liu, J. Sun
Summary: This study designed a duplex medium-entropy alloy with outstanding mechanical responses at low temperatures, showing that its strength and ductility vary with temperature. The alloy exhibits excellent strength-ductility synergy, especially with unique B2 cracking behavior observed at low temperatures.
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
Multidisciplinary Sciences
Chongle Zhang, Xiangyun Bao, Mengyuan Hao, Wei Chen, Dongdong Zhang, Dong Wang, Jinyu Zhang, Gang Liu, Jun Sun
Summary: While grain boundary engineering has limitations, chemical boundary engineering enables the creation of metallic materials with ultrafine heterogenous microstructures, enhancing mechanical properties.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Guangya Li, Yang Yang, Boyuan Gou, Jinyu Zhang, Jiao Li, Yaqiang Wang, Lingfei Cao, Gang Liu, Xiangdong Ding, Jun Sun
Summary: By controlling the defects of coherent twin boundaries (CTBs) through Cr segregation at kinks and grain boundaries (GBs), high strength and excellent structural-mechanical stability can be achieved, providing a new perspective for the design of purified Cu alloys.
Article
Chemistry, Physical
Hang Xue, Chong Yang, Frederic De Geuser, Peng Zhang, Jinyu Zhang, Bin Chen, Fuzhu Liu, Yong Peng, Jianjun Bian, Gang Liu, Alexis Deschamps, Jun Sun
Summary: Lightweight design and advanced energy applications require high-strength Al alloys for high-temperature use. However, current commercial high-strength Al alloys are limited to low-temperature applications due to difficulties in achieving both high thermal stability and large volume fraction of coherent nanoprecipitates. In this study, we demonstrate a strategy to stabilize coherent nanoprecipitates in Sc-added Al-Cu-Mg-Ag alloys, resulting in exceptional creep resistance and tensile strength at 400 degrees C. The formation of the stable nanoprecipitates is triggered by ledge-aided in situ phase transformation between slow-diffusing Sc and fast-diffusing Cu atoms. This method shows promise for the development of advanced high-temperature light alloys for large-scale industrial production.
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.
