Article
Nanoscience & Nanotechnology
Cheng Liu, Xiaohua Yang, Jianchao Peng, Bin Liu, Qun Luo, Qian Li, Kuo-Chih Chou
Summary: The deformation behaviors of a dual-phase Mg alloy containing α-Mg and 18R-LPSO phases were investigated in this study. The 18R phase, accounting for 11.3 vol.%, contributed to 23.0% of the overall alloy deformation. The coordinated twinning deformation of α-Mg matrix through the slip of basal dislocations and the kinking deformation of Mg slices induced by the 18R phase were observed during the early stage of deformation. At the end of deformation, a large number of T2-type stacking faults were generated, improving the ductility of the alloy. This work provides a novel strategy for designing high-strength and good ductility dual-phase Mg alloys.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Yunhe Zheng, Laure Bourgeois, Jian-Feng Nie
Summary: This study investigated the structure of precipitates in Mg-Zn-Al alloys, revealing new structural features and proposing that the rod-shaped precipitates can be described by tiling of different shapes.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Physical
Jayshri Dumbre, Shravan K. Kairy, Elaf Anber, Timothy Langan, Mitra L. Taheri, Thomas Dorin, Nick Birbilis
Summary: Scandium (Sc) containing Al-Si model alloys were heat-treated to form (Al,Si)(3)Sc phase at 350 degrees C and V-phase (AlSc2Si2) at above 450 degrees C. The hardening of the alloys was attributed to the coherent nanoscale (Al,Si)(3)Sc precipitates, while significant softening was observed due to the formation of coarse V-phase. The V-phase was found to have a rod morphology and six new orientation relationships with the alpha-Al matrix were determined using TEM.
JOURNAL OF ALLOYS AND COMPOUNDS
(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
Nanoscience & Nanotechnology
Frank Niessen, Azdiar A. Gazder, David R. G. Mitchell, Elena V. Pereloma
Summary: Microstructure evolution during the 3-point bending of a metastable beta Ti-10V-2Fe-3Al alloy containing 5% alpha was dominated by the formation of deformation-induced alpha '' martensite. The nucleation of alpha '' plates from {580}(alpha '') habit planes at alpha-beta interfaces, impingement with high-angle boundaries, and subsequent thickening led to a build-up of strain energy inducing {130} < 310 >(alpha '') twinning. The study also revealed the activation of {130}< 310 >(alpha '') twinning by alpha '' impingement in a metastable beta matrix.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Chemistry, Physical
Munmun Basak, Md Lutfor Rahman, Md Farid Ahmed, Bristy Biswas, Nahid Sharmin
Summary: Cobalt ferrite nanoparticles were synthesized using co-precipitation technique with different precipitating agents, affecting the structure and size distribution. Various analysis methods showed highly correlated results, with SSP method being the most compatible.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Katarzyna Stan-Glowinska, Amelia Zieba, Lukasz Rogal
Summary: This study investigates the microstructures and mechanical properties of two conventionally cast Al-Mg-Zn base alloys during aging process. The results show that the Ga-bearing alloy exhibits higher hardness and tensile strength, which can be attributed to its higher precipitate number density. In addition, the structure of formed precipitates differs between the two alloys.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Alok Singh, Takanobu Hiroto, Hiroyuki Watanabe, Naoko Ikeo, Toshiji Mukai, Koichi Tsuchiya
Summary: Addition of Al to equiatomic high entropy alloy promotes formation of BCC phase and sigma phase. Straining by caliber rolling induces morphological changes related to planar faults, where sigma phase nucleates first on the matrix faults followed by formation of B2 phase driven by elemental concentration changes. This study provides insights into the formation mechanisms of different phases in the alloy.
MATERIALS CHARACTERIZATION
(2021)
Article
Nanoscience & Nanotechnology
Kaixuan Li, Yuanlin Zhuang, Ligong Zhao, Dongshan Zhao, He Zheng, Shuangfeng Jia, Ying Zhang, Peili Zhao, Jianian Gui, Jianbo Wang
Summary: The study investigated the interaction between deformation twinning and long period stacking ordered (LPSO) structures in an Mg-based alloy, showing the hindrance of LPSO structures and stacking faults to twinning. The in-situ experiments revealed that thick LPSO plates effectively retard the twinning propagation, and the closer spacing between LPSO structures further suppresses twin propagation. Additionally, the study discussed the resistance of stacking faults to twinning at the atomic scale, and the strengthening effect of LPSO structures on suppressing twinning growth.
SCRIPTA MATERIALIA
(2022)
Article
Nanoscience & Nanotechnology
Abhinav Parakh, Andrew C. Lee, Stella Chariton, Melody M. Wang, Mehrdad T. Kiani, Vitali B. Prakapenka, X. Wendy Gu
Summary: Precipitate-matrix interactions govern the mechanical behavior of precipitate strengthened Al-based alloys. We studied the high-pressure behavior of Al7075 alloy separately from the high strain-rate behavior. High pressure can significantly enhance the strength of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Nadine Eissmann, Uwe Muehle, Uwe Gaitzsch, Gunnar Walther, Thomas Weissgaerber, Bernd Kieback
Summary: The effect of titanium addition beyond the solubility limit was investigated to demonstrate the precipitation hardening possibility of the Cantor alloy CoCrFeMnNi. Following appropriate heat treatment, a significant increase in hardness was detected due to nanometer-sized precipitates identified through TEM analysis.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Review
Materials Science, Multidisciplinary
Frank Niessen, Elena Pereloma
Summary: This review summarizes the current understanding of the alpha '' martensite transformation in metastable beta Ti alloys under different stress conditions using in situ techniques. The review identifies the strengths and weaknesses of different techniques in elucidating the martensitic transformation and discusses the macro- and micro-level mechanical behavior caused by the phase transformation. It also highlights the research questions for further investigation.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Metallurgy & Metallurgical Engineering
Shuhui Lv, Qiang Yang, Fanzhi Meng, Jian Meng
Summary: This study investigates the instantaneous reactions of Al, Mn, Zn, Zr, and Y with Ni to understand their mechanisms in removing Ni impurity. The results reveal the formation of Al4NiY and Al4Ni(Y,Zr) intermetallic phases, which efficiently remove Ni and settle at the bottom of the melt. Adding Y to Mg-Al based alloys also contributes to the removal of Fe and Ni, improving the alloys' corrosion resistance and strength.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Chemistry, Physical
Daniel Irmer, Charbel Moussa, Lisa T. Belkacemi, Mohamed Sennour, Alan Vaissiere, Vladimir A. Esin
Summary: The effect of cold rolling on the precipitation kinetics of the hardening phase was investigated in AA2024. Cold rolling induced faster coarsening kinetics and nucleation/growth of the S-phase, resulting in lower hardness of pre-deformed AA2024-T8 compared to the undeformed state. Cold rolling also led to a fine and homogeneous distribution of hardening precipitates and a different aspect ratio of S-phase precipitates. These findings may be applicable to other precipitation-hardened alloys as well.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Zhichun Zhou, Binbin Jiang, Jianke Qiu, Linglei Zhang, Jiafeng Lei, Rui Yang, Kui Du
Summary: This study investigates the mechanism of crack formation in titanium alloys with lamellar microstructure under low-cycle dwell fatigue. The accumulation of residual dislocations and local tensile stress at the α/β interfaces are found to be the key factors leading to the formation of dwell fatigue cracks.
SCIENCE CHINA-MATERIALS
(2023)
Article
Chemistry, Physical
Vei Wang, Jun-Ping Du, Hidetoshi Somekawa, Shigenobu Ogata, Wen Tong Geng
Summary: This study examines the segregation of rare earth alloying elements in magnesium and its effect on grain boundary sliding. It is found that the segregation of manganese enhances the grain boundary sliding and promotes the ductility of magnesium.
Article
Materials Science, Multidisciplinary
Elango Chandiran, Rintaro Ueji, Yukiko Ogawa, Kenta Nagata, Hidetoshi Somekawa, Masahiko Demura
Summary: A new concept for the alloy design of advanced structural steels was proposed based on the experimental elaboration of deformation behaviour in two novel medium carbon bainitic steels. The chemical composition and heat treatment conditions were designed using sparse mixed regression modelling. The results showed that both steels exhibited high tensile strength and good elongation. Steel A showed greater post-uniform elongation, while Steel B showed larger uniform elongation.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Nanoscience & Nanotechnology
Rintaro Ueji, Hidetoshi Somekawa, Tadanobu Inoue, Toru Hara
Summary: This study reports the preferable condition for kinking in the compression of pearlitic steel. The deformation microstructure and three-dimensional reconstruction analysis reveal the mechanisms involved in the kinking process.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Hidetoshi Somekawa, Motohiro Yuasa, Daisuke Ando, Yoshikazu Todaka
Summary: The application of large strain to Mg-9at.%Y-6at.%Zn alloy leads to the formation of high density deformation kink boundaries. Shear strain is a controllable parameter for inducing kink boundaries effectively, especially in wrought-processed alloys containing the LPSO phase.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Hidetoshi Somekawa, Jangho Yi, Hiromi Takahashi, Takanobu Hiroto, Koichi Tsuchiya
Summary: Experimental studies have revealed that many cavities are formed at grain boundaries and grain boundary triple junctions of fine-grained magnesium specimens during plastic deformation at room temperature, and the size and density of these cavities increase with the progression of deformation. The majority of cavities are controlled by plasticity, and their growth rate is similar to those observed in superplastic magnesium alloys tested at elevated temperatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Yukiko Ogawa, Alok Singh, Hidetoshi Somekawa
Summary: The mechanical properties of a coarse-grained hexagonal close packed (hcp) single phase Mg-Sc alloy with two different textures, randomized or weakened, were investigated. Both textures exhibited a high elongation of over 30% and a moderately high ultimate tensile strength of about 240 MPa. Transmission electron microscopy (TEM) observations revealed the activation of both a- and c-component dislocations in the grain interiors, away from grain boundaries by over 20 μm. Thus, pyramidal slip can occur within the grain interiors of a coarse-grained Mg-Sc alloy.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Elango Chandiran, Yukiko Ogawa, Rintaro Ueji, Hidetoshi Somekawa
Summary: The effect of grain size and strain rate on the room-temperature compression of pure magnesium was studied. It was found that the deformation mechanisms and grain-boundary sliding were significantly influenced by grain size and strain rate, and the Hall-Petch relationship broke down under certain conditions. Additionally, the deformation mode had a negligible impact on the dominant deformation mechanisms and the Hall-Petch breakdown.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Motohiro Yuasa, Ryoichi Sato, Takao Hoshino, Daisuke Ando, Yoshikazu Todaka, Hiroyuki Miyamoto, Hidetoshi Somekawa
Summary: Mg-9 at%Y-6 at%Zn and Mg-2 at%Y-1 at%Zn alloys were processed by equal-channel-angular extrusion (ECAE) to investigate their microstructure evolution and local hardness. The area fraction of the kink bands in the Mg-9 at%Y-6 at%Zn alloys increased with increasing the number of ECAE passes, resulting in higher hardness. In the Mg-2 at%Y-1 at%Zn alloys, the microstructural evolution of the alpha-Mg matrix phase and long-period stacking ordered (LPSO) phase by 1-pass ECAE and the increase in local hardness were discussed.
MATERIALS TRANSACTIONS
(2023)
Article
Nanoscience & Nanotechnology
Rintaro Ueji, Kenji Nagata, Hidetoshi Somekawa, Masahiko Demura
Summary: This study designed the chemical compositions and heat treatment conditions for low-alloyed TRIP steel using a sparse mixed regression method. Experimental results confirmed that these conditions provided high strength and large elongation. Evaluating the metallurgical parameters highlighted two different design concepts.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Mechanical
Hynek Lauschmann, Jaromir Kukal, Katerina Jirouskova, Karel Tesar
Summary: A locally controlled filtering (LCF) method is proposed to automatically extract dominant structures from rough and irregular fracture surfaces. The reduction of surface shapes can be adjusted by a numerical parameter, and a feature called the parameter of reduction is defined for comparing outputs. An application on a 3D sample of steel P92 fracture surface is presented and compared with other filtration solutions using Fourier and wavelet transforms and trap-ezoidal filtration windows. Despite wavelets being more effective, both transformations result in a higher presence of undesired smaller objects in the output compared to LCF under the same reduction parameter value. Various applications of fully automatic LCF on fractures of steels P92 and AISI 304L are demonstrated.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Chemistry, Physical
Hidetoshi Somekawa, Kimiyoshi Naito
Summary: The effect of micro-alloying with different elements on grain boundary sliding behavior at intermediate temperatures was examined. The micro-alloying element affects the damping capacity and the tensile response of the alloy. The partial contribution of grain boundary sliding to deformation is the major reason for the deviation of experimental results from calculated values.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Naomi Nishimura, Kazumasa Masaki, Wei Tan, Reona Iimura, Hiroaki Kobayashi, Kei Nishikawa, Toshihiko Mandai, Hidetoshi Somekawa, Yoichi Tominaga
Summary: To improve the cycle performance of Mg metal batteries, a polymer coating (PSTFSI-Mg) was applied on the surface of spinel-type MgMn2O4 cathode. The polymer coating promoted electron transfer between particles, as confirmed by transmission electron microscopy. Density functional theory calculations revealed that the polymer reduced the energy gap between the valence band maximum of MgMn2O4 and the highest occupied molecular orbital level of the electrolyte, thus suppressing electrolyte degradation.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Hidetoshi Somekawa, Kei Nishikawa, Taku Moronaga, Takahito Ohmura
Summary: Two types of lithium metals with different average grain sizes were successfully produced through extrusion process and rapid molding process. The hardness of the metals was found to be influenced by grain size, decreasing with a finer grained structure, which is contrary to the trend observed in other light-weight pure metals. The fine-grained Li metal exhibited a large strain rate dependence and unusual behavior, attributed to the contribution of grain boundary sliding to deformation. Additionally, the fine-grained Li metal showed better electrochemical characteristics in terms of over-potential and voltage response during charging and discharging operations.
JOURNAL OF POWER SOURCES
(2023)
Article
Nanoscience & Nanotechnology
Hidetoshi Somekawa, Norie Motohashi, Shuji Kuroda, Toshihiko Mandai
Summary: Wide and thin Mg foils with thicknesses between 35 & mu;m and 400 & mu;m without any edge cracks are successfully produced. The initial microstructure in the billet is effective and essential for the processing. The mechanical properties of the foils are influenced by the foil thickness, as shown by hardness and tensile tests.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Hidetoshi Somekawa, Motohiro Yuasa
Summary: The secondary formability and the effect of shape application on induced kink boundaries in Mg-9at.%Y-6at.%Zn alloy were investigated through experimental and numerical studies. A tube-shaped alloy without any cracks was successfully formed with kink boundaries associated with the applied shear strain. Numerical results showed a substantial shear strain at the contact region, but with an opposite shear direction after tube formation, indicating the possibility of de-kinking behavior. Additionally, the formed alloy exhibited higher hardness by 30 Hv compared to the un-processed alloy, and the correlation between kink density and hardness was consistent with literature results on wrought-processed Mg-Y-Zn alloys.
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.
