Article
Crystallography
Patricia Krenckel, Yusuke Hayama, Florian Schindler, Theresa Troetschler, Stephan Riepe, Noritaka Usami
Summary: The study demonstrates the feasibility of the SMART approach on larger ingots, which successfully limits the generation of structural defects by maintaining the monocrystalline structure using functional defects, resulting in increased monocrystal area and electrical material quality.
Article
Chemistry, Physical
Yi Zeng, Yongsheng Ren, Wenhui Ma, Hui Chen, Jing Cao, Yun Lei, Zhengxing Wang, Kazuki Morita
Summary: Developing new methods for solar photovoltaic power generation is an effective solution for future energy shortages. This study proposes a novel method for separating bulk silicon from a Si-Sn melt using electromagnetic stirring. The results show that electromagnetic stirring increases the growth rate of Si and a lower moving rate improves the enrichment percentage of Si. The downward directional solidification at a rate of 3 μm/s achieved a large area of bulk Si with an enrichment percentage of up to 88.16%.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Liang Qiao, Shuangming Li, Xin Cao, Hong Zhong, Yumin Wang
Summary: The anisotropy of solid-liquid interface energy plays a fundamental role in dendritic morphology and pattern selection during solidification. Different dendritic morphologies are observed in Al-3 wt% Mg single crystals along different crystal orientations. A non-regular dendritic pattern selection map is constructed to explain the occurrence of different dendrites during alloy solidification.
Article
Chemistry, Multidisciplinary
Yifan Dang, Xinbo Liu, Can Zhu, Yuma Fukami, Shuyang Ma, Huiqin Zhou, Xin Liu, Kentaro Kutsukake, Shunta Harada, Toru Ujihara
Summary: In the solution growth of SiC crystal, controlling the behavior of macrosteps is crucial to reduce defects and achieve a high-quality grown layer. A simulation method is proposed to understand and control the macrosteps, which involves a global 2D computational fluid dynamics model, a local 3D model near the growth front, and a kinetics model describing the movement of macrosteps. The simulation demonstrates that a sophisticated control pattern, involving periodically switching the flow direction, can yield a grown crystal with a uniform macrostep distribution and ideal step height on the whole surface.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Crystallography
T. Hughes, A. J. Robinson, S. McFadden
Summary: Competitive growth between neighbouring (111) dendrites was investigated in directional solidification experiments using a transparent model alloy. The results showed that the secondary arms of (111) dendrites grew with more favourable orientation than those of (100) dendrites, allowing them to outgrow and stabilize along the growth direction. The deviation from the Walton-Chalmers rule of competitive growth was found to be probabilistic and dependent on the initial seeding and 3D nature of the experiments.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Materials Science, Multidisciplinary
Jilong Kang, Min Zhao
Summary: The directional solidification process of Co-Sn alloys was studied, with a specific focus on the unique 'seaweed' morphology observed in this system. It was found that the withdrawal velocity had a significant effect on the solid/liquid interface morphology as well as the growth location of the primary phases.
MATERIALS SCIENCE AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Zhiqiang Zhang, Xuegong Yu, Shuai Yuan, Deren Yang
Summary: This study developed a method to identify and measure the shape of the three-dimensional solid/liquid interface, and investigated its relationship with defect density and solar cell efficiency of silicon ingots. By optimizing the heat dissipation structure and the type of heater power, a highly symmetrical and mild convex shape of the interface was achieved, resulting in reduced defect densities and improved solar cell efficiency.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Review
Chemistry, Physical
Koichi Kakimoto, Xin Liu, Satoshi Nakano
Summary: This paper evaluates the impurity transport phenomena in crystal growth furnaces of Czochralski and directional solidification methods based on a model of global analysis and experimental research.
Article
Materials Science, Multidisciplinary
T. Hughes, A. J. Robinson, S. McFadden
Summary: Directional solidification experiments with transparent alloy systems often show multiple dendrites growing with preferential alignment. An experimental apparatus with a novel computer vision algorithm was used to automatically detect and track multiple columnar dendrite tips, providing statistical and qualitative insights.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Green & Sustainable Science & Technology
Minako Imose, Daigo Araki, Md Azhar Uddin, Yoshiei Kato, Kiyoshi Kinoshita
Summary: The radial directional solidification technique was investigated for recycling kerf loss silicon powder into SOG-Si. The purification behavior of metallic impurities Fe and Ca determined the specific resistivity, with Fe purification being most effective at a solid fraction of 0.8 before rapidly diminishing.
JOURNAL OF SUSTAINABLE METALLURGY
(2022)
Article
Crystallography
Seyed Amin Nabavizadeh, Supriya Upadhyay, Mohsen Eshraghi, Sergio D. Felicelli, Surendra N. Tewari, Richard N. Grugel
Summary: During directional solidification of alloys in microgravity, dendritic growth is influenced by diffusive transport conditions. Studies have found that presence of voids at the melt-crucible interface can lead to the formation of spurious grains. Numerical simulations and experimental observations demonstrate that Marangoni convection plays a significant role in the trajectory and rotation of dendrite fragments in alloy melts.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Physics, Multidisciplinary
Yun-Chun Liu, Yong-Chao Liang, Qian Chen, Li Zhang, Jia-Jun Ma, Bei Wang, Ting-Hong Gao, Quan Xie
Summary: In this study, the rapid solidification processes of Ni47Co53 alloy at five cooling rates were investigated using molecular dynamics simulation. The results showed that different microstructures and dislocation evolutions occurred at different cooling rates. The research provides valuable insights into the dislocation mechanism and its influence on crystal structure at atomic scales.
Article
Multidisciplinary Sciences
Lotan Portal, Iryna Polishchuk, Maria Koifman Khristosov, Alexander Katsman, Boaz Pokroy
Summary: Dislocations in metals significantly impact their hardness and strength, leading to local chemical corrosion and reactivity. A unique autocatalytic mechanism was discovered in which inorganic semiconducting gold(I) cyanide nanowires form within preexisting dislocation lines in a plastically deformed Au-Ag alloy, with the growth of the nanowires being dependent on the presence of catalytic dislocation outcrops.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Green & Sustainable Science & Technology
Pengting Li, Lian Dong, Zhiqiang Hu, Shiqiang Ren, Yi Tan, Dachuan Jiang, Xiaogang You
Summary: This paper presents a method of using electron beam melting coupled with directional solidification to purify silicon scraps. Hard particles are effectively removed by the collision and clustering under the action of melt convection. Metal impurities are concentrated in the top center of the ingot due to the accelerated convection caused by the electron beam. The obtained silicon ingot has low impurity content and can be used for high-performance polycrystalline silicon production.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Materials Science, Multidisciplinary
Daniel N. Blaschke
Summary: This work aims to derive a general anisotropic solution for pure screw dislocations applicable to slip systems featuring a reflection symmetry in anisotropic crystals, in order to study pure screw dislocations without mixing with edge dislocations. However, further generalizations to arbitrary mixed dislocations as well as regularizations of the dislocation core are left for future work.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
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.