Article
Chemistry, Physical
Linye Zhu, Shuntaro Ida, Georg Hasemann, Manja Krueger, Kyosuke Yoshimi
Summary: Mo-Si-B near-eutectic alloys were prepared by arc-melting or crucible-free zone-melting methods. Directionally solidified alloy showed an increase in the volume fraction of eutectic cells compared to arc-melted alloy, with well-aligned and rod-shaped Moss and T2 phases. Different growth orientations of phases were observed in the two types of alloys, with the Mo3Si matrix showing a weak preference in orientation along the solidification direction.
Article
Chemistry, Physical
W. G. Yang, G. Hasemann, M. Yazlak, B. Gorr, R. Schwaiger, M. Krueger
Summary: The solidification behavior near the ternary V-ss-V3Si-V5SiB2 eutectic reaction in the V-Si-B system was experimentally investigated, and the composition of the reaction was determined. A comparison was made with calculated results to reveal the competitive solidification behavior between the two-phase and three-phase eutectic growth.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Iztok Naglic, Blaz Leskovar, Zoran Samardzija, Bostjan Markoli
Summary: This study investigated the influence of gallium addition on the phases formed in Al-Mn alloys during casting, revealing that an increase in gallium content led to the formation of IQCs and DQCs in the alloys. Microanalysis showed that IQCs contained more gallium and less manganese compared to DQCs.
Article
Materials Science, Multidisciplinary
Paul Chao, George R. Lindemann, Allen H. Hunter, Ashwin J. Shahani
Summary: This study investigates the solidification of an Al-Cu alloy to understand the emergence of patterns within eutectic colonies. A new synchrotron-based imaging method is introduced to uncover the morphological transitions in situ and in 3D. The method provides high temporal and spatial resolution, enabling direct insight into the lamella-to-rod transition mechanism.
Article
Chemistry, Physical
Masaki Tahara, Kazuya Hasunuma, Hideki Hosoda
Summary: This study investigated the decomposition process of the isothermal alpha '' phase in beta-Ti alloys, and found that the resulting alpha + beta dual phase inherited the microstructural characteristics of the alpha ''(iso) phase. The research results indicate the existence of a strict variant selection rule between the decomposed alpha and beta phases, with a specific variant combination observed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Nanoscience & Nanotechnology
X. W. Li, Y. Ruan, C. H. Sun, M. H. Yang, B. Wei
Summary: The peri-eutectic transition L+6-Fe ->gamma-Fe(Ni)+Fe2Ti in ternary Fe66.5Ni17.6Ti15.9 alloy was investigated using directional solidification technique. The primary phase and peri-eutectic had a common orientation relationship, while the eutectic had multiple orientation relationships. This study provided evidence for different growth mechanisms and clarified the nucleation and growth of the peri-eutectic phase.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
D. V. Louzguine-Luzgin, Yu. P. Ivanov, A. L. Greer
Summary: The crystallization behavior of a Cu58Y37Sc5 metallic glassy alloy was investigated using various methods. Differential scanning and isothermal calorimetries were performed to study the phase transformations. X-ray diffractometry studies showed the simultaneous formation of Cu2Y, CuY, and CuSc crystalline phases, indicating eutectic crystallization, while the isothermal crystallization kinetics corresponded to primary crystallization. Transmission electron microscopy observations revealed a complex crystallization process involving heterogeneous nucleation on pre-existing particles.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
V. T. Witusiewicz, U. Hecht, J. Fernandez, J. Rodriguez, J. M. Ezquerro
Summary: This study focuses on the transient responses of rod-like eutectic patterns under different growth velocities, revealing a deterioration of hexagonal order under transient growth conditions regardless of imposed acceleration or deceleration. Spacing adjustment is achieved through abrupt morphological transitions that destroy the previous order.
Article
Nanoscience & Nanotechnology
U. Hecht, A. Vayyala, P. Barriobero-Vila, N. Navaeilavasani, S. Gein, I. Cazic, J. Mayer
Summary: The medium entropy alloy Al0.75CrFeNi2.1 with hypo-eutectic composition was processed by laser powder bed fusion (LPBF). Non-equilibrium solidification conditions led to the formation of cellular and lamellar microstructures. In-situ high-energy synchrotron X-ray diffraction (HEXRD) and atom probe tomography (APT) were used to study the microstructure evolution during post-build annealing. The mechanical properties of the alloy, including tensile strength and elongation at fracture, were evaluated and compared to martensitic steels.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Optics
Junjing Deng, Yudong Yao, Yi Jiang, Si Chen, Tim M. Mooney, Jeffrey A. Klug, Fabricio S. Marin, Christian Roehrig, Ke Yue, Curt Preissner, Zhonghou Cai, Barry Lai, Stefan Vogt
Summary: Ptychography is a high-resolution diffraction imaging technique that is sensitive to experimental variations. High-speed data acquisition with short exposure can minimize the impact of experimental variations, and continuous multi-pass scan via high-speed ptychography can achieve high-resolution imaging. This low-dose scan strategy is important for radiation-sensitive sample studies and time-resolved imaging.
Article
Chemistry, Multidisciplinary
Lan Zhan, Ninghui Li, Xiangge Qin
Summary: The solidification process of the molten pool has been studied using a simulation system based on molecular dynamics. The results show that the molten pool forms two atomic layers of pre-melting on the base metal before solidification, and then grows with the exposed and ordered atoms of the base metal as the nuclei. These findings provide a foundation for the in-depth study of the molten pool solidification process at the atomic scale.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Physical
Won-hyuk Lee, Yeonju Oh, Min-Gu Jo, Heung Nam Han, Yanghoo Kim
Summary: The effects of Nb content on microstructures and mechanical properties in Co-free CrFeNi2Nbx alloys were investigated. Increasing Nb content led to changes in microstructures and improved mechanical properties, with a reduction in ductility. The CrFeNi2Nb0.6 alloy achieved a high maximum fracture strength.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Walter J. Williams, Tiankai Yao, Xiaofei Pu, Luca Capriotti
Summary: This study focuses on the micro-burnup (BU) studies of the uranium-zirconium (U-Zr) fuel system, where the microstructure undergoes a transformation from as-fabricated to starting microstructure in the reactor. Two U-Zr specimens were irradiated and the results show that the U-22.5 at.% Zr specimen retained its bulk features, while the U-52.8 at.% Zr alloy transformed into an equiaxed granular microstructure immediately upon reactor insertion. The study also discovers a face-centered-cubic Zr rind on the surface of the sample, indicating a possible diffusion-based process for the Zr-rind decomposition.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Chemistry, Physical
Jong Woo Choi, Jeong Tae Kim, Je Hyung Park, Sung Hwan Hong, Hae Jin Park, Taek Jib Choi, Ki Buem Kim
Summary: This study evaluated the microstructure and mechanical properties of as-cast non-equiatomic medium entropy alloys, showing that MEAs with 10% Cr content exhibited the highest yield strength and excellent plastic strain. Abnormal deformation behaviors, such as double-yielding phenomenon, were observed in the stress-strain curve, which was related to phase transformation during compressive loading as confirmed through TEM analysis.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
X. Wang, W. Zhai, J. Y. Wang, B. Wei
Summary: The solidification process of high-entropy FeCoNi2Al0.9 alloy was modulated using 20 kHz power ultrasound with a maximum amplitude of 13 μm. The eutectic structures were composed of L12 and B2 phases growing synergistically by the K-S relationship. Increasing the ultrasound amplitude resulted in refined eutectic cell width and regular lamellar spacing, increased proportion of strictly semi-coherent L12/B2 interfaces, and suppressed solute concentration fluctuation in each eutectic phase. The steady-state cavitation and acoustic flow had a significant influence on the evolution of the eutectic microstructure. The alloy exhibited increased yield strength, ultimate strength, and total elongation compared to statically solidified alloy, providing an effective approach to improve the mechanical properties and overcome the strength-ductility trade-off in high-entropy alloys with eutectic structures.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Shanmukha Kiran Aramanda, Sai Kiran Salapaka, Sumeet Khanna, Kamanio Chattopadhyay, Abhik Choudhury
Article
Materials Science, Multidisciplinary
Hemaprabha Elangovan, Sanchita Sengupta, Ravishankar Narayanan, Kamanio Chattopadhyay
Summary: Silicon nanoparticles with a particle size distribution of around 80 nm were successfully obtained through controlled impact mode cryomilling of semiconductor grade silicon wafers. The microstructure analysis revealed a two-phase structure in each particle, with the crystalline silicon partially transformed into an amorphous phase. Further etching of the two-phase nanocomposites resulted in the dissolution of the amorphous phase, producing free nanoparticles of approximately 2 nm in size that exhibited UV range photoluminescence and showed potential for sensors and other optical applications.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Shanmukha Kiran Aramanda, Sumeet Khanna, Sai Kiran Salapaka, Kamanio Chattopadhyay, Abhik Choudhury
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2020)
Article
Materials Science, Multidisciplinary
Sumeet Khanna, Shanmukha Kiran Aramanda, Abhik Choudhury
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2020)
Article
Materials Science, Multidisciplinary
Semanti Mukhopadhyay, Prafull Pandey, Nithin Baler, Krishanu Biswas, Surendra Kumar Makineni, Kamanio Chattopadhyay
Summary: The paper investigates the influence of Ti addition on Ta stabilized gamma/gamma' two-phase Co-based superalloys. It was found that an increase in Ti content reduces the gamma/gamma' lattice misfit and Mo partitioning to the gamma', while improving high-temperature strength. Additionally, aging of the alloys resulted in a morphological transition of the precipitates and a preference for Ti partitioning to the gamma'.
Article
Chemistry, Physical
Shriparna Mukherjee, Shanmukha Kiran Aramanda, Surafel Shiferaw Legese, Alexander Riss, Gerda Rogl, Olu Emmanuel Femi, Ernst Bauer, Peter Franz Rogl, Kamanio Chattopadhyay
Summary: The study utilized controlled in situ grown lamellar composites of (Cu2Te)(62.02)-(Sb2Te3)(37.98) to investigate a remarkable variation in thermoelectric transport properties as a function of microstructural length scale and direction-dependent arrangement of phases. Quantitative evaluation of the microstructure revealed an anisotropy in properties as a function of measurement direction in the microstructural landscape. The findings have implications for engineering thermoelectric devices in terms of power factor and output power density.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Abhishek Sharma, Chandan Mondal, Kamanio Chattopadhyay, Dipankar Banerjee, Surendra Kumar Makineni
Summary: This study provides a detailed analysis of the deformation micromechanisms involved in the compressive creep of a directionally solidified Cobalt-base superalloy at various stresses and temperatures. The results show different deformation modes under different stress levels, leading to variations in the macroscopic creep behavior.
Article
Metallurgy & Metallurgical Engineering
Poorwa Gore, Om Puri Gosain, Mahander Pratap Singh, Bikramjit Basu, Kamanio Chattopadhyay
Summary: This study investigates the oxidation behavior of Inconel 740H and Haynes 282 alloys at high temperature and pressure. The results show that both alloys have a low oxidation growth rate, which is dominated by the Cr2O3-rich outer layer and the internal oxidation region rich in oxides of Al and Ti.
OXIDATION OF METALS
(2022)
Article
Materials Science, Multidisciplinary
Ujjval Bansal, Mahander Pratap Singh, Sukla Mondol, Shyam Kanta Sinha, Surendra Kumar Makineni, Aloke Paul, Kamanio Chattopadhyay
Summary: This study systematically investigates the microstructure evolution in Al-Cu alloys and explores the role of Hf and Si in ordered precipitates and intermetallic compound formation. With the promotion of Si, coherent and spherical ordered phases can be formed in the alloy matrix. These ordered precipitates play a significant role in the precipitation of metastable compounds in copper-containing alloys and exhibit good mechanical properties at elevated temperatures.
Article
Materials Science, Multidisciplinary
Dipanjan Kumar, Mahander Pratap Singh, N. Ravishankar, Kamanio Chattopadhyay
Summary: The study focuses on the metallurgical phase transformations in the development of interconnects for thermoelectric devices. It investigates the phase decomposition of the high-temperature Ni5Pb2Te3 phase in PbTe/Ni heterointerfaces through advanced analytical techniques and presents a thermodynamic framework for predicting such transformations.
Article
Chemistry, Physical
Yoshihito Kawamura, Hayato Yamagata, Shin-ichi Inoue, Takanori Kiguchi, Kamanio Chattopadhyay
Summary: The paper introduces a high-strength magnesium alloy in an Mg-Zn-Y system that is strengthened by ordered nanoclusters in a solid solution matrix. The new arrangement, known as cluster-arranged nanoplates (CANaPs), consists of layers of ordered Zn6Y8 clusters separated by magnesium planes. CANaPs thicken over time and temperature, but their dispersion decreases. The presence of CANaPs in a heat-treated alloy moderately improves the tensile strength, and their dispersion correlates with the formation of kink bands during hot extrusion, leading to a significant increase in yield stress.
JOURNAL OF ALLOYS AND COMPOUNDS
(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.
