Article
Materials Science, Multidisciplinary
Y. H. Yang, Q. Lei, P. Zhang, W. Y. Wang, X. K. Zhang, Y. P. Li, K. C. Zhou, Z. Li
Summary: The study demonstrated that the addition of Nb can stabilize metastable Cr3Cu precipitates by reducing the interfacial energy between Cu and Cr, resulting in a higher high-temperature strengthening effect. The Cu-Cr-Nb alloy with stable L1(2) structured Cr3Cu precipitates showed significantly improved high-temperature strength compared to the b.c.c. structured Cr precipitates.
MATERIALS RESEARCH LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Alan J. Ardell
Summary: This study re-examines the kinetics of γ' precipitates in binary Ni-Al alloys. It was found that a previous investigation had made an unfortunate error in unit conversion, rendering all conclusions unreliable. The re-analysis shows that the equations describing skeletal coarsening kinetics are not trustworthy in providing useful quantitative information on the coarsening of non-skeletal microstructures and the elastic energy of γ' precipitates with misfit.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Multidisciplinary
Francesco Torre, Teodor Huminiuc, Elodia Musu, Tomas Polcar, Francesco Delogu, Antonio Mario Locci
Summary: Nanocrystalline W-Al alloys with Al content up to 20 at.% were produced via high energy ball milling. The alloys exhibited decreased crystallite size and improved sinterability after 70-100 hours of mechanical treatment. The addition of Al also enhanced coarsening resistance in the alloys.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Nanoscience & Nanotechnology
Spencer Doran, Yonggang Yan, Liuqing Yang, Jae-Kyung Han, Di Chen, Kun Wang, Youxing Chen, Megumi Kawasaki, Tianyi Chen
Summary: Nanocrystalline materials often experience radiation-enhanced grain coarsening, but high entropy alloys (HEA) may have superior radiation tolerance due to their intrinsic sluggish diffusion. In this study, CoCrFeNiMn HEA samples were processed via high-pressure torsion (HPT) to form nanograins with unsaturated and saturated plastic deformation. After Ni ion irradiation, grain growth was observed in both samples, but the 8T sample showed stronger radiation tolerance. This resistance is attributed to a unique nanodomain microstructure formed within the radiation-coarsened grains of the 8T sample.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Sarah Dine, Elodie Bernard, Nathalie Herlin, Christian Grisolia, David Tingaud, Dominique Vrel
Summary: Recent studies have shown that low grain sizes in tungsten can improve its ductility and machinability, as well as resistance to ablation and spallation, which are important properties for its use in fusion environments. A new powder metallurgy-based methodology has been proposed for the fabrication of bulk nanostructured tungsten and tungsten-chromium alloys, which show promising mechanical properties and resistance to oxidation.
Article
Chemistry, Physical
D. A. Santana, K. R. Santos, C. S. Kiminami, F. G. Coury
Summary: Multi-principal element alloys (MPEAs) with dispersed nanometric precipitates are currently attracting attention in the literature. A new precipitation-hardened multi-principal element alloy, Cr29.7Co29.7Ni35.4Al4.0Ti1.2, shows promising coarsening kinetics and thermal stability, with improved mechanical properties compared to conventional superalloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Vickey Nandal, R. Sarvesha, Sudhanshu S. Singh, E-Wen Huang, Yao-Jen Chang, An-Chou Yeh, Suresh Neelakantan, Jayant Jain
Summary: The study investigated the effect of pre-deformation on aging response of non-equiatomic high entropy alloys, showing that pre-deformed HEAs exhibit reduced peak-aging time due to enhanced precipitation kinetics from increased dislocation densities. Microstructural analysis revealed distinct precipitate size and distribution characteristics in pre-deformed and aged alloys, providing insights into their role in aging response and coarsening kinetics.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
J. X. Hou, J. Y. Zhang, J. X. Zhang, J. H. Luan, Y. X. Wang, B. X. Cao, Y. L. Zhao, Z. B. Jiao, X. J. Liu, W. W. Song, P. K. Liaw, T. Yang
Summary: The precipitation morphologies, coarsening kinetics, elemental partitioning behaviors, grain structures, and tensile properties of L12-strengthened Ni39.9Co20Fe15Cr15Al6Ti4-xNbxB0.1 (x = 0 at.%, 2 at.%, and 4 at.%) high-entropy alloys were investigated. Substituting Ti with Nb resulted in a transition from spheroidal to cuboidal precipitates, increased coarsening kinetics, and phase decomposition at 800°C. Excessive Nb addition led to grain boundary precipitation and phase decomposition from L12 to lamellar-structured D019 phase. Partial substitution of Ti with Nb resulted in a chemically complex and thermally stable L12 phase, ensuring stable phase structure and clean grain boundaries, leading to excellent high-temperature mechanical properties at 700°C.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
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
K. G. Wang
Summary: The kinetics of phase coarsening in a dense binary, two-phase system were theoretically studied and existing relations were recovered and generalized. Equations for particle size distribution and coarsening were rigorously derived. An interesting finding is that the scaling exponent, m, for the kinetics of phase coarsening at ultra high volume fractions takes values in the range 2 < m < 3, depending on the precise volume fraction of the dispersed phase, when varied over the narrow range 0.9 < V-V < 1. The particle size distributions derived in this study depend on volume fractions, which is different from Wagner's particle size distribution for interface-reaction-controlled phase coarsening. The current work substantiates that the kinetics of phase coarsening at ultra high volume fractions exhibits a blend of both interface-reaction-controlled and volume diffusion-controlled phase coarsening.
Article
Nanoscience & Nanotechnology
Tiffany Wu, A. Plotkowski, A. Shyam, David C. Dunand
Summary: This study investigates the microstructures, thermal stability, ambient temperature strengthening, and creep resistance of three ternary Al-Ce-Ni alloys. The results show that the high volume fraction of intermetallic phases and extremely fine eutectic spacing/fiber diameter contribute to high ambient strengthening and enhanced creep resistance. The alloys also exhibit coarsening resistance up to 425 degrees C and remain substantial creep resistance at 300 degrees C, making them excellent materials for high temperature applications.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Hanns Gietl, Takaaki Koyanagi, Xunxiang Hu, Makoto Fukuda, Akira Hasegawa, Yutai Katoh
Summary: This study provides experimental evidence of radiation-enhanced recrystallization in tungsten and undoped tungsten-rhenium alloys under fusion-relevant environments. It is found that potassium or lanthanum doping in tungsten alloys improves resistance to radiation-enhanced grain growth. The study also highlights the importance of considering radiation-enhanced recrystallization in the design and application of tungsten plasma-facing components in future nuclear fusion reactors.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Zhenchang Hou, Zhihua Nie, Zhichao Liu, Jun Gao, Fang Hao, Chengwen Tan, Yandong Wang
Summary: An as-cast Ni81W10Al9 alloy with remarkable mechanical properties was developed by adjusting the alloying element with appropriate enthalpy of mixing. The yield strength of the alloy reached about 640 MPa, which is approximately three times higher than its Al-free counterpart. Extensive L12 phase nanoscale precipitations were generated in the alloy, providing strong strengthening effects by blocking dislocation sliding.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Multidisciplinary Sciences
Matthias S. Frei, Cecilia Mondelli, Rodrigo Garcia-Muelas, Jordi Morales-Vidal, Michelle Philipp, Olga V. Safonova, Nuria Lopez, Joseph A. Stewart, Daniel Curulla Ferre, Javier Perez-Ramirez
Summary: This study investigates the complex interplay between nanostructure and product selectivity of nickel-promoted In2O3 in CO2 hydrogenation to methanol. The presence of nickel on the oxide surface forms InNi3 patches, which boost methanol production by providing neutral hydrogen species. Ratios of nickel to In content influence the formation of different structures and the production of CO and methane in the reaction.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
J. D. Robson, A. D. Smith, J. Guo, J. M. Donoghue, A. E. Davis
Summary: Competitive continuous and discontinuous precipitation (CP and DP) in magnesium alloys have been studied in-situ for the first time. The migration of the high angle grain boundary (reaction front, RF) behind which DP occurs is found to be irregular instead of steady-state. Local effects play a key role in causing the irregular motion of the RF.
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.