Article
Materials Science, Multidisciplinary
Ning Su, Qingchen Deng, Yujuan Wu, Liming Peng, Kun Yang, Qiang Chen
Summary: This paper investigates the dissolution, refinement, and re-precipitation of LPSO structure/SFs in an Mg-Gd-Zn-Mn alloy through hot extrusion. The results suggest that refinement is dominated by the misalignment and re-dissolution mechanisms, with dislocation slips and rapid solute atom diffusion playing key roles. The evolution model of LPSO structure/SFs during continuous dynamic recrystallization is proposed based on the findings.
MATERIALS CHARACTERIZATION
(2021)
Article
Materials Science, Multidisciplinary
Qiang Yang, Shuhui Lv, Zixiang Yan, Xiru Hua, Xin Qiu, Jian Meng
Summary: This study reveals strong ductility asymmetry in extruded Mg alloys containing LPSO plates, which is mainly caused by deformation steps in LPSO plates, contributing significantly to compressive ductility. The results provide fundamental insights into deformation modes and mechanisms of thin LPSO plates, as well as a better understanding of the ductility asymmetry in extruded Mg alloys containing LPSO plates.
MATERIALS & DESIGN
(2021)
Article
Nanoscience & Nanotechnology
Kai Guan, Mariko Egami, Daisuke Egusa, Hajime Kimizuka, Michiaki Yamasaki, Yoshihito Kawamura, Eiji Abe
Summary: In this study, SRO solute clusters in the I-1 type LPSO phases in Mg-CoY alloys have been investigated using atomic-resolution STEM and first-principles calculations. The Co3Y5 SRO cluster model embedded across the I-1-type SFs has been successfully constructed to enhance the energetic stability of the LPSO phases. The findings reveal the crucial role of solute SRO clusters in the formation and stability of LPSO phases in ternary Mg alloys.
SCRIPTA MATERIALIA
(2022)
Article
Metallurgy & Metallurgical Engineering
Kai Guan, Daisuke Egusa, Eiji Abe
Summary: The microstructures of an as-cast Mg97.49Ho1.99Cu0.43Zr0.09 alloy were investigated using atomic resolution high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The study revealed the presence of ordered long period stacking/order (LPSO) phases and short-range order (SRO) clusters embedded in stacking fault layers. The results support the importance of L1(2)-type TM6RE8 clusters in the formation of LPSO phases.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
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
Materials Science, Multidisciplinary
Krishna Yaddanapudi, Brandon Leu, M. Arul Kumar, Xin Wang, Julie M. Schoenung, Enrique J. Lavernia, Timothy J. Rupert, Irene J. Beyerlein, Subhash Mahajan
Summary: This study investigated {(1) over bar 012} tensile twins terminating inside the grains of a deformed Mg-Y alloy using transmission electron microscopy. Crystallographic features of the terminating twins and associated slip structures were quantified and analyzed, with local stresses computed using crystal plasticity simulations. Basal < a > and < c + a > matrix glide were found to accommodate the plastic stresses near the terminating twins, with defect contrast consistent with lattice dislocations and twinning partials observed along the twin boundary. A dislocation reaction was proposed to establish the interrelationship between matrix glide and {(1) over bar 012} twinning in Mg-Y alloys.
Article
Nanoscience & Nanotechnology
Cyril Cayron
Summary: Recent studies have reported a hexagonal phase in high carbon steels, but it has been shown that this structure is actually the result of double diffraction and streaking effects caused by twins and stacking faults, rather than a superstructure. Similar misunderstandings have also been found in papers reporting exotic structures in aluminum, copper, and diamonds.
SCRIPTA MATERIALIA
(2021)
Article
Metallurgy & Metallurgical Engineering
Fanzhi Meng, Shuhui Lv, Qiang Yang, Xin Qiu, Zixiang Yan, Qian Duan, Jian Meng
Summary: This study investigated the components and crystal structures of intermetallic phases in a gravity die-cast Mg-6.0Zn-1.5Nd-0.5Zr alloy using transmission electron microscopy. The results revealed multiple intermetallic phases and various internal faults in the alloy. The study also revealed new orientation relationships between different intermetallic phases.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Chemistry, Physical
Hsin-Li Liang, Che-Wei Tsai, Sheng Guo
Summary: This study successfully designed corrosion-resistant CoCrFeMoNi HEAs with single-phase structure using two strategies, and validated the effectiveness of these methods through thermal stability. The corrosion resistance of these HEAs was found to be competitive compared to Hastelloy C276.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Nanoscience & Nanotechnology
M. L. Jenkins, G. D. W. Smith
Summary: Researchers attempted to discredit the identification of the 9R structure of copper precipitates in iron, but were unable to provide convincing evidence. High-resolution micrographs and other observations supported the robust identification of the 9R structure, highlighting flaws in the opposing interpretation.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
M. R. Gazizov, A. O. Boev, C. D. Marioara, R. Holmestad, M. Yu Gazizova, R. O. Kaibyshev
Summary: The study analyzed the coherent edge interface structures of thin {111}(Al) Omega plates in a peak-aged Al-Cu-Mg-Ag alloy using atomic-resolution STEM, finding that these edge interfaces can tilt from their orthogonal orientations to the broad plate surfaces. The edge interface tilts are correlated with shear component orientations along the broad plate surfaces and vary with plate thicknesses, while Cu atoms tend to occupy specific atomic sites near the edge interfaces in the Al matrix region.
MATERIALS CHARACTERIZATION
(2022)
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
Engineering, Biomedical
Diana C. Martinez, Anna Dobkowska, Romy Marek, Hanna Cwieka, Jakub Jaroszewicz, Tomasz P. Plocinski, Crtomir Donik, Heike Helmholz, Berengere Luthringer-Feyerabend, Berit Zeller-Plumhoff, Regine Willumeit-Roemer, Wojciech Swieszkowski
Summary: This study investigated the degradation of an Mg-0.45Zn-0.45Ca (ZX00) screw in vitro and in vivo. The results showed that the ZX00 alloy promoted bone healing and the formation of new bone. Despite the correlation with the production procedure, the ZX00 alloy was still suitable for temporary bone implants.
BIOACTIVE MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Zhiwen Zheng, Cong Peng, Qingan Zhang
Summary: In this work, the hydrogen storage properties of the Mg85Zn6Y9 alloy with 94 wt.% of 18R-type LPSO phase were investigated. The 18R phase easily decomposes into various phases during ball milling under a hydrogen atmosphere. The Mg85Zn6Y9 alloy exhibits better hydrogen storage kinetics and cycle durability compared to pure Mg due to the catalytic effect of YH2/YH3 and the inhibition role of the Laves phase.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Masafumi Matsushita, Kohtaro Masuda, Ryohei Waki, Hiroaki Ohfuji, Michiaki Yamasaki, Yoshihito Kawamura, Yuji Higo
JOURNAL OF ALLOYS AND COMPOUNDS
(2019)
Article
Materials Science, Multidisciplinary
Taekyung Lee, Michiaki Yamasaki, Yoshihito Kawamura, Jongbin Go, Sung Hyuk Park
METALS AND MATERIALS INTERNATIONAL
(2019)
Article
Materials Science, Multidisciplinary
Daria Drozdenko, Michiaki Yamasaki, Kristian Mathis, Patrik Dobron, Pavel Lukac, Naoya Kizu, Shin-ichi Inoue, Yoshihito Kawamura
MATERIALS & DESIGN
(2019)
Article
Materials Science, Multidisciplinary
Kristian Mathis, Dana Drozdenko, Gergely Nemeth, Stefanus Harjo, Wu Gong, Kazuya Aizawa, Michiaki Yamasaki, Yoshihito Kawamura
FRONTIERS IN MATERIALS
(2019)
Article
Materials Science, Multidisciplinary
M. Egami, I. Ohnuma, M. Enoki, H. Ohtani, E. Abe
MATERIALS & DESIGN
(2020)
Article
Materials Science, Multidisciplinary
M. Egami, I. Ohnuma, M. Enoki, H. Ohtani, E. Abe
MATERIALS TRANSACTIONS
(2020)
Article
Materials Science, Multidisciplinary
Daisuke Egusa, Hidetoshi Somekawa, Eiji Abe
MATERIALS TRANSACTIONS
(2020)
Article
Nanoscience & Nanotechnology
Hidetoshi Somekawa, Daisuke Egusa, Eiji Abe
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2020)
Article
Multidisciplinary Sciences
Motoki Yako, Yasuhiko Ishikawa, Eiji Abe, Kazumi Wada
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2020)
Article
Materials Science, Multidisciplinary
Mitsuhiro Itakura, Masatake Yamaguchi, Daisuke Egusa, Eiji Abe
Summary: Solute clusters in long period stacking order (LPSO) alloys play a crucial role in their unique plastic behavior, but there is uncertainty regarding the presence of interstitial atoms in these clusters. Using density functional theory calculations, it was found that solute clusters in Mg-Y-Zn LPSO alloy should include interstitial atoms, primarily Mg. This finding simplifies the atomistic modeling of solute clusters in these alloys and suggests that increased vacancy density accelerates cluster growth through the emission of vacancies from the cluster.
Article
Materials Science, Multidisciplinary
Toshihiro Hara, Daisuke Egusa, Mami Mihara, Hiroki Tanaka, Ikuo Ohnuma, Eiji Abe
Summary: The study found that the softening phenomenon in the Al-Fe alloy is attributed to the highly purified aluminum matrix, leading to the occurrence of dynamic recovery and/or recrystallization in deformation ranges.
MATERIALS TRANSACTIONS
(2021)
Article
Materials Science, Multidisciplinary
Daisuke Egusa, Koji Inoue, Yasuyoshi Nagai, Eiji Abe
Summary: The study found that kink boundaries (KBs) undergo reconstruction during post-annealing, forming local hexagonal close-packed Mg regions and enhancing thermal stability. The reconstruction of dislocation structures plays an important role in solute-enriched face-centered cubic layers within LPSO structures.
MATERIALS CHARACTERIZATION
(2021)
Article
Polymer Science
Tatsuhiko Murayama, Eiji Abe, Hiromu Saito
Summary: Through heat elongation treatment, the mechanical properties of extruded high-density polyethylene film were improved, including increased tensile strength and disappearance of the yield point. Experimental results showed that elongation led to a more regular lamellar structure, increased chain orientation, and suppression of lamellar fracture and void formation.
Article
Nanoscience & Nanotechnology
Kai Guan, Mariko Egami, Daisuke Egusa, Hajime Kimizuka, Michiaki Yamasaki, Yoshihito Kawamura, Eiji Abe
Summary: In this study, SRO solute clusters in the I-1 type LPSO phases in Mg-CoY alloys have been investigated using atomic-resolution STEM and first-principles calculations. The Co3Y5 SRO cluster model embedded across the I-1-type SFs has been successfully constructed to enhance the energetic stability of the LPSO phases. The findings reveal the crucial role of solute SRO clusters in the formation and stability of LPSO phases in ternary Mg alloys.
SCRIPTA MATERIALIA
(2022)
Article
Metallurgy & Metallurgical Engineering
Kai Guan, Daisuke Egusa, Eiji Abe, Jinghuai Zhang, Xin Qiu, Qiang Yang, Jian Meng
Summary: The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy was investigated. The addition of Gd inhibited the segregation behavior of Zn in the Mg3Sm phase and improved the tensile yield stress of the alloy. Gd-modified alloys exhibited significant age-hardening effect, attributed to the high-volume fraction and high density nano-scale precipitates.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)