Article
Nanoscience & Nanotechnology
S. Hanada, N. Masahashi, S. Semboshi, T. K. Jung
Summary: By investigating the effects of composition and cold groove-rolling on Young's modulus in beta Ti-Nb-Sn ternary alloys, low Young's modulus was successfully achieved. Different phases were observed in the alloys, and the lowest Young's modulus was mainly attributed to lattice deformation strain and texture development.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Haoliang Wang, Daniel Kuok Zheng Lai, Chenghao Song, Yuliang Zhao, Jun Cheng, Matthias Bonisch, Zhenzhong Sun
Summary: This study develops a novel and efficient processing strategy for creating multi-phase Ti-alloys with zero thermal expansion and enhanced rigidity. By heating to specific temperatures, the microstructure of Ti22Nb transforms and precipitates nano-scale phases, resulting in the formation of multi-phase microstructures. The thermal expansion and Young's modulus of the alloy can be modified through aging process, leading to improved properties.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Jae-Hwan Kim, Jong-Min Jung, Hyunbo Shim
Summary: Through the study of Fe-20Mn-12Cr-3Ni-3Si alloys, it was found that with the increase in cold rolling degree, the tensile strength gradually increased, the elongation decreased, and the damping capacity reached its maximum around a 30% cold rolling degree. There is a relationship between tensile properties and damping capacity, with the damping capacity tending to decrease in the high-strength area, while increasing in the low-strength area as the strength increases.
Article
Nanoscience & Nanotechnology
Luis Umbelino dos Santos, Kaio Niitsu Campo, Rubens Caram, Eder Socrates Najar Lopes
Summary: In this study, the influence of oxygen content on the microstructure and mechanical properties of Ti-Nb alloys was evaluated. The results showed that increasing oxygen content slightly affected the thickness of alpha plates and beta-transus, but improved hardness and compressive yield stress. Solid-solution strengthening by Nb and oxygen, along with microstructural refinement by Nb addition, were responsible for these improvements.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Sinara Borborema, Vitor de Holanda Ferrer, Adriana da Cunha Rocha, Caio Marcello Felbinger Azevedo Cossu, Aline Raquel Vieira Nunes, Carlos Angelo Nunes, Loic Malet, Luiz Henrique de Almeida
Summary: This study analyzed the influence of phase precipitations on the microstructure and mechanical properties of heat-treated Ti-12Mo-xNb alloys. The results showed that the addition of Nb suppressed the formation of the alpha '' phase, but a small amount of omega phase was still observed. The addition of Nb increased the Young's modulus, while the decrease in the omega phase reduced the hardness of the alloy.
Article
Materials Science, Multidisciplinary
Praveen Sathiyamoorthi, Peyman Asghari-Rad, Alireza Zargaran, Gangaraju Manogna Karthik, Hyeonseok Kwon, Hyoung Seop Kim
Summary: In this study, a Fe50Co25Ni10Al5Ti5Mo5 medium entropy alloy was fabricated through casting and processed by hot rolling and heat treatment to achieve high strength via martensitic structure and precipitation. The resulting sample exhibited fine lath martensite structure, two types of precipitates, retained FCC phase, and high dislocation density, leading to superior tensile properties with an extremely high tensile strength of 1.7 GPa and good uniform elongation of 8%.
Article
Nanoscience & Nanotechnology
A. Thoemmes, I. A. Bataev, D. Lazurenko, A. A. Ruktuev, I. Ivanov, C. R. M. Afonso, A. Stark, A. M. Jorge
Summary: The study on suction-cast Ti-Nb alloys shows that different Nb contents have a significant impact on the microstructure and phase transformations of the alloys, resulting in different phase compositions. The mechanical properties, such as Young's modulus, are directly influenced by the phase composition of the alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Bingnan Qian, Min Yang, Lola Lilensten, Philippe Vermaut, Fan Sun, Frederic Prima
Summary: The complex hierarchical twinning-detwinning mechanism in α''-martensite and the associated rubber-like behavior have been clarified in TRIP/TWIP Ti-12Mo unprecedentedly via comprehensive in-situ investigations.
MATERIALS RESEARCH LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Rizal Arifin, Fahmi Astuti, Malik Anjelh Baqiya, Yoyok Winardi, Yoga Arob Wicaksono, Darminto, Ali Selamat
Summary: Research has shown that TiAl alloys have good structural stability and lightweight properties at high temperatures, making them capable of withstanding significant compression loads. Molecular dynamics simulations revealed that the tensile and compressive strengths of TiAl alloys are significantly affected by temperature, and the crystal structure changes under compressive loading.
Article
Materials Science, Multidisciplinary
Cong Wu, Qinyang Zhao, Shixing Huang, Yongqing Zhao, Lei Lei, Junqiang Ren, Qiaoyan Sun, Lian Zhou
Summary: The deformation behavior and mechanisms of beta-quenched near beta Ti-5321 alloy were studied using in-situ tensile testing and microscopy analysis. Slip activities, crystal rotation, and stress-induced martensite transformation were identified as the major deformation mechanisms. The dominant slip system was {110}<111>, and the rotation of beta grains accommodated the increased macrostrain. Stress-induced martensite alpha '' exhibited multiple characteristics, and deformation twinning and slip bands effectively accommodated local strain.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Hugo Schaal, Philippe Castany, Pascal Laheurte, Thierry Gloriant
Summary: A new beta Ti-22Zr-11Nb-2Sn biomedical titanium alloy was fabricated using in situ laser powder bed fusion technique. Optimized manufacturing parameters were determined through iterative design of experiments to achieve dense and homogeneous parts with low unmolten niobium fraction. The alloy exhibited a beta-type microstructure with a low Young's modulus and high tensile strength, making it suitable for medical devices in osseous site.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Xingjun Liu, Qinghua Peng, Shaobin Pan, Jingtao Du, Shuiyuan Yang, Jiajia Han, Yong Lu, Jinxin Yu, Cuiping Wang
Summary: A machine learning prediction method is proposed to efficiently and reliably predict the microstructures and mechanical properties of biomedical titanium alloys. Using this method, a low modulus beta-Ti alloy was successfully designed.
Article
Materials Science, Multidisciplinary
Alena S. Gornakova, Boris B. Straumal, Andrey A. Mazilkin, Natalia S. Afonikova, Mikhail Karpov, Elena A. Novikova, Alexander Tyurin
Summary: Four titanium-iron binary alloys were studied, with changes in phase composition, nanohardness, and Young's modulus investigated before and after high pressure torsion (HPT). Alloys with higher iron content after HPT exhibited a larger fraction of the omega phase. Nanohardness values of the material at the center of the HPT samples ranged between 4.4 and 5.8 GPa, regardless of preliminary annealing conditions. Young's modulus was found to be a sensitive parameter to structural and phase changes, increasing by a factor of 1.5 after annealing in the (alpha + beta) region compared to the (alpha + TiFe) region.
Article
Engineering, Chemical
Alena S. Gornakova, Anna Korneva, Alexander I. Tyurin, Natalia S. Afonikova, Askar R. Kilmametov, Boris B. Straumal
Summary: The paper investigates the impact of HPT on phase transformations and mechanical properties in Ti alloys with different Mo contents. The results show that HPT can significantly increase the hardness and nanohardness of the samples, and the values of hardness and Young's modulus depend on the applied load.
Article
Nanoscience & Nanotechnology
Dan-dan Ma, Ping Yang, Xin-fu Gu, Feng-E Cui
Summary: The thermally induced martensite can be effectively restrained by refining grains or introducing crystal defects, providing a nearly full austenite phase for the subsequent TRIP process. Fine-grained samples exhibit better plasticity and higher strength, while bimodal elongated-grained samples demonstrate the highest strength and sufficient plasticity due to the delay in martensitic transformation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Metallurgy & Metallurgical Engineering
Yunwei Gui, Lingxiao Ouyang, Yujie Cui, Huakang Bian, Quanan Li, Akihiko Chiba
Summary: By utilizing dynamic recrystallization mechanisms during hot indirect extrusion, grain refinement in the magnesium-rare earth alloy was successfully achieved, especially through the formation of high angle grain boundaries to promote the generation of new grain nuclei, improving the efficiency of dynamic recrystallization.
JOURNAL OF MAGNESIUM AND ALLOYS
(2021)
Article
Materials Science, Multidisciplinary
Qinqin Wei, Guoqiang Luo, Rong Tu, Jian Zhang, Qiang Shen, Yujie Cui, Yunwei Gui, Akihiko Chiba
Summary: The dual-phase Re0.5MoNbW(TaC)(0.5) composite, synthesized by arc melting, exhibited remarkably high-temperature strength with a yield strength of approximately 901 MPa and a true ultimate compressive strength of around 1186 MPa at 1200 degrees C. The semi-coherent interface between the BCC phase and carbide, along with dipolar dislocation walls in the BCC phase and restricted dynamic interaction between defects in the carbide, provided effective strengthening effects.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Manufacturing
Kenta Yamanaka, Asumi Kuroda, Miyu Ito, Manami Mori, Huakang Bian, Takahisa Shobu, Shigeo Sato, Akihiko Chiba
Summary: The study quantitatively analyzed the dislocation structures formed in Ti-6Al-4V alloy during additive manufacturing processes, revealing significant differences in microstructures between LB-PBF and EB-PBF, affecting dislocation density and crystallite size. High-energy synchrotron radiation analysis showed that nanosized beta-phase precipitates exhibited a higher dislocation density than the surrounding alpha (alpha')-matrix.
ADDITIVE MANUFACTURING
(2021)
Article
Metallurgy & Metallurgical Engineering
Biaobiao Yang, Chenying Shi, Siyu Zhang, Jingjing Hu, Jianwei Teng, Yujie Cui, Yunping Li, Akihiko Chiba
Summary: This study investigated the twinning-detwinning behavior in a strongly basal-textured Mg-Li alloy using quasi-in-situ EBSD. The loading path was found to affect the twinning behavior and detwinning variants selection. Non-Schmid twinning behavior was observed in the first step compression, while Schmid's law well predicted the detwinning variants selection. The study also found that the Schmid factors for twinning decreased with compression, whereas those for detwinning increased due to prior twinning behavior.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Materials Science, Multidisciplinary
Yujie Cui, Kenta Aoyagi, Huakang Bian, Yuichiro Hayasaka, Akihiko Chiba
Summary: Increasing Al concentration in Mg-Al-Zn alloys can restrict the growth of twins and reverse motion of twin boundaries, leading to the formation of smaller-sized twins and higher fractions of secondary twins and 2-5 degrees boundaries during reverse tension. The increased amount of Al solute atoms plays a crucial role in enhancing the strengthening effect on the motion of twin boundaries.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Yunwei Gui, Yujie Cui, Huakang Bian, Quanan Li, Lingxiao Ouyang, Akihiko Chiba
Summary: This study systematically investigated the microstructural evolution and deformation mechanism of an aged Mg-5Y-2Nd-3Sm-0.5Zr alloy during uniaxial compression at room temperature. The results showed a transition from slip and twinning to pyramidal II dislocations dominating the deformation mechanism.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Akihiko Chiba, Yohei Daino, Kenta Aoyagi, Kenta Yamanaka
Summary: Preheating and ball milling can effectively suppress smoking in the powder bed fusion-electron beam melting process, even without preheating, smoking can be prevented after ball milling. This is because the oxide film undergoes a transition during ball milling.
Article
Chemistry, Multidisciplinary
Kazuhisa Sato, Hirotaro Mori
Summary: The study successfully formed Pt2Si in Pt/a-SiOx bilayer and a-SiOx/Pt/a-SiOx sandwiched films by electron irradiation, indicating that the extent of the interfacial area plays a key role in Pt2Si formation. The morphology of Pt islands extensively changed during Pt2Si formation process.
Article
Nanoscience & Nanotechnology
Jiaxiang Li, Kenta Yamanaka, Akihiko Chiba
Summary: The study compared the deformation behaviors of different Mo content HEAs and found that lattice distortion is a key factor affecting the deformation behavior of HEAs, with high-Mo HEAs exhibiting a higher strain-hardening rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Kazuhisa Sato, Toshiya Matsushita
Summary: Structural defects in (Ta1-xTix)Se-2 compounds with anisotropic electrical conductivity were studied by observing cross-sectional images. Intercalants were found in the widest space between Se atoms, independent of Ti content or thermal history. The presence of Ti stabilized the 1T structure, reducing stacking faults. Chemical composition was found to dominate the structural defects in these compounds.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Kazuhisa Sato, Shunya Takagi, Satoshi Ichikawa, Takuya Ishimoto, Takayoshi Nakano
Summary: Using transmission electron microscopy and energy-dispersive x-ray spectroscopy, we investigated the microstructure and solute segregation in the melt pool boundary of orientation-controlled 316L austenitic stainless steel produced by laser powder bed fusion. The solidification cellular microstructures were visualized by solute segregation, and Mn-Si-O inclusions were observed along the lamellar boundaries and dislocation cell walls. The widening of cellular spacing at the bottom of the melt pool boundary was attributed to the decrease in cooling rate.
Article
Nanoscience & Nanotechnology
Jiaxiang Li, Kenta Yamanaka, Yuichiro Hayasaka, Akihiko Chiba
Summary: A Co0.95Cr0.8Fe0.25Ni1.8Mo0.475 high-entropy alloy underwent heavy cold rolling and subsequent aging at 773 K, resulting in Suzuki hardening. Enrichment of Co atoms at stacking faults (SFs) was observed, which pinned down partial dislocations and enhanced the deformation resistance. Additionally, enrichment of Co and Mo atoms at SFs was observed in a low dislocated, strain-aged specimen, leading to differences in segregation. The calculated local stacking fault energy (SFE) with the segregation of Co and Mo atoms was -30.6 mJ/m2 at the aging temperature, indirectly leading to the formation of wide SFs.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Manufacturing
Seungkyun Yim, Huakang Bian, Kenta Aoyagi, Kenta Yamanaka, Akihiko Chiba
Summary: We investigated the influence of particle morphology on flowability and spreading behavior using a discrete element method (DEM) simulation. The addition of non-spherical particles decreased flowability and resulted in a transition from rolling flow to cascading flow under rotation. Adding elongated particles decreased the quality of the powder bed due to force-arch formation and strong particle interlocking. Spherical particles with low spreading velocity are desirable for improving the quality of the powder bed in the PBF-AM process.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Kazuhisa Sato, Hirotaro Mori
Summary: We propose a new mechanism of crystallization in amorphous alloys mediated by additional solute atoms produced by electronic excitation. Extensive crystallization of a-SiOx/a-Pd-Si/a-SiOx sandwiched Pd-19at%Si amorphous alloy occurred by electron irradiation. This crystallization can be achieved not only at room temperature but also at 90 K.
Article
Metallurgy & Metallurgical Engineering
Hitomi Iwaizako, Masayuki Okugawa, Kenji Saito, Yuichiro Koizumi, Akihiko Chiba, Yuichi Tachiya, Manabu Ohnuma, Kingo Kuritani
Summary: The study focused on the spinodal decomposition structures of Fe-Cr-Co alloys, revealing that cold rolling affects the process of spinodal decomposition, and the existence of dislocation structures can accelerate the process and result in an inhomogeneous microstructure.
TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN
(2021)
