Article
Nanoscience & Nanotechnology
Yuanxiang Zhang, Nuojin Wang, Tianmo Wu, Yang Wang, Feng Fang, Shirui Wu, Wenbo Sun, R. D. K. Misra, Xiaoming Zhang, Guodong Wang, Guo Yuan
Summary: Based on the characteristics of Cu-Fe monotectic alloy, this study investigated the selection process of low-energy grain boundaries of delta-Fe grains (>25 μm) suspended in liquid copper. The distribution of grain boundaries was analyzed by EBSD, and it was observed that sigma 3 and sigma 9 high-angle grain boundaries with low energy were preferentially formed between delta-Fe grains at temperatures ranging from 1100 to 1150 degrees Celsius. After heat treatment at 1200 degrees Celsius, the delta-Fe grains agglomerated into a spherical shape with sigma 1 grain boundaries dominating. This elucidates the selective attachment of low-energy interfaces between floating grains in the liquid phase.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Jilong Kang, Jinfu Li
Summary: The addition of minor Nb can destabilize the eutectic solidification interface in eutectic alloys, leading to different morphological evolutions. Temperature gradient affects the interface morphology of different eutectic alloys, while the structures formed by Ni and Co in the eutectic have different effects on seaweed growth.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Physics, Multidisciplinary
Chang-Sheng Zhu, Zi-Hao Gao, Peng Lei, Li Feng, Bo-Rui Zhao
Summary: The multi-phase field model of grain competitive growth during directional solidification of alloy is established in this study. The grain boundary evolution and grain elimination during the competitive growth of SCN-0.24-wt% camphor model alloy bi-crystals are investigated, and the effects of different crystal orientations and pulling velocities on grain boundary microstructure evolution are quantitatively analyzed. Several important findings are obtained.
Article
Materials Science, Multidisciplinary
Phillip Dumitraschkewitz, Matheus A. Tunes, Cameron R. Quick, Diego Santa Rosa Coradini, Thomas M. Kremmer, Parthiban Ramasamy, Peter J. Uggowitzer, Stefan Pogatscher
Summary: The solidification behavior of a eutectic AlCu specimen is investigated using in situ scanning transmission electron microscope experiments. By varying the cooling conditions, different rapid solidification morphologies are obtained. Additionally, the spheroidization of lamellas during annealing at elevated temperatures is studied.
Article
Nanoscience & Nanotechnology
Megan J. McCarthy, Timothy J. Rupert
Summary: This study investigates the migration behavior of a faceted Sigma 11 boundary in Cu doped with Ag atoms, revealing that solute atoms segregate to a facet with more free volume and greatly reduce boundary velocity in one migration direction. However, a directionally-dependent motion mechanism can escape solute pinning and speed up migration in the other direction, uncovering a new mechanism of chemically-induced anisotropy in grain boundary mobility.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Min Ling, Yi-Long Liang
Summary: A systematic study was conducted on the grain boundary microstructure evolution of GH4169 nickel-based superalloy during the micro-strain stage of thermal deformation. The study found the occurrence of grain boundary slip, grain rotation, and grain boundary migration. Twin boundaries displayed a stable structure during thermal deformation and the synergistic mechanism of grain boundary slip and migration was identified as the primary mechanism during the micro-strain stage.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Hongbo Xie, Shanshan Li, Peijun Yang, Chuangwei Liu, Weitao Jia, Gaowu Qin
Summary: This study systematically investigated the precipitation behaviors of nano-sized secondary phases in grain boundaries. The results show that the minimization of GB elastic strain drives the segregation of solutes to the interfacial strain zones, and the selective substitution of solutes resulting in the nucleation of face-centered-cubic (FCC) phase from the bi-crystalline hexagonal closed-packed (HCP) lattices. The interphase boundary strain driven solute diffusion plus atomic shuffling can realize the growth of parent phase {1100}HCP lattices to the {110}FCC atomic-planes.
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)
Article
Chemistry, Physical
A. Hassani, A. Khmich, A. Hasnaoui
Summary: Molecular dynamics simulations were used to investigate the structure of mismatched Al/Ni and Ag/Cu interfaces on low-index substrate surfaces. Embedded Atom Potentials were employed to mimic atomic interactions. The effect of substrate orientation on the adlayer structure was studied. Results showed that the adlayer on the (1 1 1) substrate exhibited a coincidence site lattice with a rotation (alpha) relative to the substrate, potentially containing dislocations and twin boundaries. Deposition of the adlayer on the substrate led to slight atom shuffling and dislocations in the substrate, producing rectangular structures. On the (001) substrate, the accommodation of a triangular structure on a square lattice (substrate) resulted in a shift of atomic rows and the formation of dislocations, with multiple square structures agglomerating to form a polycrystal with grain boundaries and vacancies. However, inward adsorption on the (1 1 0) substrate limited the extension of adsorbed atoms, resulting in linear cracks. Relaxation of atoms adsorbed on these cracks led to a change in vacancy shape from linear to staircase.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Haneul Han, Chaerin Lee, Youjung Kim, Jinhyun Lee, Rosa Kim, Jongryoul Kim, Bongyoung Yoo
Summary: The research demonstrates successful Cu-Cu direct bonding at low temperature using high defect density Cu (HD2 Cu), with grain growth mainly driven by strain energy release.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Yang Zenan, Zhang Zhen, Guo Chunwen, Pan Hao, Wang Zhen, Zhang Qiang, Huang Chaohui, Wang Zhijun
Summary: The competitive growth and grain boundary selection in directional solidification play a crucial role in understanding the misoriented grains in the fabrication of single crystal blades.
RARE METAL MATERIALS AND ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
T. S. Prithiv, Baptiste Gault, Yujiao Li, Dustin Andersen, Nathalie Valle, Santhana Eswara, Dirk Ponge, Dierk Raabe
Summary: The addition of boron (B) to steels significantly suppresses the austenite to ferrite phase transformation, increasing their hardenability. The mechanisms of B segregation and how exactly B suppresses the ferrite nucleation remain elusive.
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
Materials Science, Multidisciplinary
D. P. Rao Palaparti, V. D. Vijayanand, K. Mariappan, G. V. Prasad Reddy
Summary: The evolution of coincident site lattice (CSL) boundaries in 316LN SS was investigated under single step thermomechanical treatment (TMT). Four different TMT processes, including prior cold work (PCW) up to 5 pct and post annealing treatments up to 1273 K, were examined. The remnant strain energy in each TMT condition was calculated and the prevalence of strain-induced boundary migration (SIBM) as a mechanism for CSL generation was examined.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Lili Tian, Yinli Peng, Xing He, Yang Bai, Xiaowei Lei, Nan Wang
Summary: This study unraveled the onset mechanism of irregular eutectic growth by studying the morphology transitions in a transparent eutectic system. The results showed that a decoupled interface gradually appeared from an original coupled interface after the specimen was exposed in a thermal gradient, leading to the growth of two types of seeds under an exerted pulling rate. The findings provide new insights into the solidification dynamics of irregular eutectic systems.
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.