Updated on 2024/07/18

写真a

 
MORISHIGE,Taiki
 
Organization
Faculty of Chemistry, Materials and Bioengineering Professor
Title
Professor
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Degree

  • 博士(工学) ( 2011.3 )

Research Interests

  • Aluminum alloy

  • Magnesium alloy

  • Microstructure design

Research Areas

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Manufacturing and production engineering

  • Nanotechnology/Materials / Metallic material properties

  • Nanotechnology/Materials / Structural materials and functional materials

  • Nanotechnology/Materials / Material processing and microstructure control

Education

  • Osaka Prefecture University   Graduate School, Division of Engineering

    2011

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  • Osaka Prefecture University   Graduate School, Division of Engineering

    2008

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  • Osaka Prefecture University   Faculty of Engineering

    - 2006

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  • Osaka Prefecture University   Graduate School, Division of Engineering

    2011

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  • Osaka Prefecture University   Graduate School, Division of Engineering

    2008

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Research History

  • Kansai University   Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering   Professor

    2023.4

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  • Kansai University   Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering   Associate Professor

    2016.4 - 2023.3

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  • Norwegian University of Science and Technology   Department of Materials Science and Engineering

    2016.4 - 2017.3

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  • Kansai University   Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering   Assistant Professor

    2011.4 - 2016.3

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  • Technology Research Institute of Osaka Prefecture

    2008.4 - 2011.3

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Professional Memberships

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Papers

  • Effect of Distributions of Low Angle Grain Boundary and Dislocation Density on Strength of Al-3mass%Mg by SPD Reviewed

    Atsushi KOZAKI, Taiki MORISHIGE, Tsutomu TANAKA

    Solid State Phenomena   Vol. 353, pp 59-63   2023.12

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    Al-Mg alloys processed by Severe Plastic Deformation (SPD) have higher strength due to grain refinement by dynamic recrystallization. Generally, the relationship between grain size and strength is expressed by the Hall-Petch relationship, but the strength of Al-Mg alloys processed by SPD is higher than expected from the Hall-Petch extrapolation. This phenomenon is called "Extra-Hardening". In this study, Al-3mass%Mg alloys processed by SPD were annealed, and the fraction of grain boundaries was measured by EBSD to determine the effect of grain boundaries on the strength. The results suggest that Extra-Hardening may be an effect of strengthening by SGB, which changes significantly with the number of passes and annealing, and constant LAGB strengthening. Strength predictions using the fraction of grain boundaries were in good agreement.

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  • Optimization of Anodizing Condition for Mg-14mass%Li-3mass%Al alloy Reviewed

    Taiki MORISHIGE, Satoki TAKIYAMA, Yuka ICHIGI, Toshihide TAKENAKA

    Materials Science Forum   Vol. 1106, pp 9-13   2023.12

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    Mg-Li system alloys also has excellent cold-workability compared to commercial hcpstructured Mg alloys. However, Mg-Li alloys have poor corrosion resistance because not only that is Mg-based alloy but Li as a major alloying element is a less noble metal. For example, Mg-Li alloy sheet indicates high corrosion rate and exfoliation corrosion as a result of long-term corrosion test. The authors reported Mg-14 mass%Li-3 mass%Al alloy has the highest corrosion resistance in β-type solid solution alloy. Even though the optimized alloy composition, the alloy does not have enough corrosion resistance for practical use. In this study, anodized coating on Mg-Li alloy using phosphate solution was investigated. Anodizing of Mg-Li alloy facilitates the dissolution of substrate because of high Li concentration in this alloy. Therefore, the anodizing conditions were widely examined. As a result, the coating with approximately 15-20 μm of the surface layer was successfully formed. The surface layer was composed of MgAl2O4 and some phosphorus compounds. The thickness of anodized layer varied with the anodizing conditions. The dense surface layer was formed at a certain anodizing voltage and the corrosion resistance of anodized Mg-Li alloys was improved. However, the surface has some cracks and large flaky compounds. The formation mechanism of dense layer during anodizing were discussed.

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  • Microstructural Evolution and Distributions of Grain Boundary in SPD Processed Al-3mass%Mg alloy Reviewed

    MORISHIGE,Taiki, SUZUKI, Yuto, AIZAWA, Taiga, TANAKA, Tsutomu, HIRATA, Tomotake, TAKENAKA, Toshihide

    Materials Transactions   Vol. 64, No. 5 pp.983-987   2023.5

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    SPD-processed Al alloys have an ultra-fine-grained microstructure and extremely high strength. The strength of SPD-processed Al alloy exceeds the estimated it by the grain size using Hall-Petch relationship. SPD-processed Al has high dislocation density because the excess introduced strain remains in dynamically recrystallized grains. The excess dislocation may form the low angle grain boundary during dynamic recrystallization. Al-Mg alloy represents especially large strengthening by dislocation hardening after SPD not only smaller grain size than pure Al. This is because the stacking fault energy (SFE) of the alloy is lowered by Mg solute atom. The dislocation movement become suppressed during DRX in low SFE alloys. As a result, SPD-processed Al-Mg alloys have extremely fine-grained (~0.25 μm) microstructure. SFE of the alloy may also affect the formation of low angle grain boundary and dislocation accumulation in the grain interior. The dislocation distributions could result the degree of extra-hardening. The distributions of dislocation and low angle grain boundary in ECAE processed Al-3mass%Mg alloy were investigated by EBSD and XRD techniques. Annealing after ECAE for recovery the strain provides the relaxation of the strain hardening, in spite of the LAGB fraction remains static.

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  • Acceptable Concentrations of Cu and Ni in Corrosion Resistance of Mg-6mass% Zn alloy Reviewed

    Taiki MORISHIGE, Koki EZUMI, Masato IKOMA, Tetsuo KIKUCHI, Ryuichi YOSHIDA, Toshihide TAKENAKA

    Materials Transactions   Vol. 64, No. 4 pp.925-930   2023.4

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    Cu and Ni impurities in Mg alloys are deleterious contaminants that reduce the corrosion resistance of the alloy. Mg2Cu and Mg2Ni precipitates can cause significant anodic dissolution of the Mg matrix, owing to their potential difference. Suppression of these phases can prevent the deterioration of corrosion resistance. The neutralization of these impurities through the formation of MgZn intermetallic phases has been studied, because the atomic radii of Cu and Ni are similar to that of Zn. As a result, the MgZn2 phase may precipitate during the rapid cooling that occurs during the solidification of the Mg-6mass% Zn alloy, and introduce substitutional impurity atoms in the crystal lattice. Mg(Zn, Cu)2 and Mg(Zn, Ni)2 phases can be formed instead of Mg2Cu and Mg2Ni, in the presence of both of Zn and these impurities. The microstructures and corrosion properties of the Mg6-mass% Zn alloy with various Cu or Ni concentrations are investigated in this work. The Cu and Ni impurities are concentrated into MgZn2 phase in the Mg6-mass% Zn alloy without Mg2Cu or Mg2Ni formation when the concentrations of these impurities are within acceptable limits. Consequently, the corrosion rate of the Mg-6mass% Zn alloy with 1.4 mass% Cu or 0.25 mass% Ni is almost the same as that of the alloy without Cu and/or Ni contaminations.

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  • Effect of Electrolysis Potential and Molar Ratio of CaO to SiO2 on Si Metal Deposition in Molten CaCl2 Reviewed

    TAKAHASHI, Kosei, MORISHIGE,Taiki, TAKENAKA, Toshihide

    Materials Transactions   Vol. 64, No. 1 pp303-305   2023.1

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    The electrodeposition of Si metal in molten CaCl2 containing various types of calcium silicate has been studied at 1373-1673 K. It was shown that the influence of the molar ratio of CaO to SiO2 on Si electrodeposition was not remarkable in contrast with our previous results that the molar ratio of CaO to TiO2 strongly affected the Ti metal deposition in the similar system. Silicon metal was obtained on MoSi2 cathode in the melt by potentio-static electrolysis. The cathodic current efficiency was about 30% regardless of the added types of calcium silicate. The current efficiency tended to be better as the electrolysis potential became negative, but the electrolysis below the border potential lead to lower current efficiency due to Ca co-deposition.

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  • Corrosion Resistance of Mg Alloy with High Zn Concentration Including Impurity Cu Reviewed

    Masato Ikoma, Taiki Morishige, Tetsuo Kikuchi, Ryuichi Yoshida, Toshihide Takenaka

    Materials Science Forum   Vol. 1016, pp.592-597   2021

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  • Extra-Hardening of SPD-Processed Al-Mg Alloy with Minimum Grain Sizes Reviewed

    Taiki Morishige, Yuto Suzuki, Toshihide Takenaka

    Materials Science Forum   Vol. 1016 pp. 952-956   2021

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  • The Influence of Introduced Strains on the Exfoliation Corrosion Behavior of Mg-14mass%Li-1mass%Al alloy Reviewed

    Hayato Ikoma, Taiki Morishige, Toshihide Takenaka

    Materials Science Forum   Vol. 1016 pp.587-591   2021

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  • Effect of Pre-sintering in Silicothermic Reduction of MgO and Reduction Using Ca2SiO4 Instead of CaO

    Takeru Saimura, Taiki Morishige, Toshihide Takenaka

    Minerals, Metals and Materials Series   13 - 17   2021

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Springer Science and Business Media Deutschland GmbH  

    It was shown in our previous study that the contact condition between MgO, CaO, and Si strongly affected Mg metal production by silicothermic reduction of magnesium oxide derived from salt evaporation ponds. In this study, the influence of the contact condition of MgO, CaO, and Si in the reduction was studied
    the dependence of the reduction rate on the preparation procedure of MgO–CaO mixture and pre-sintering before the reduction was examined. A short-term sintering improved the reduction rate, but a longer sintering worsened the rate. Sintering seems effective in the improvement of contact condition, but causes the surface oxidation on Si. In this study, Si reduction with Ca2SiO4 instead of CaO was also attempted to reduce CaO consumption, but it was shown that MgO was lost by CaMgSiO4 formation.

    DOI: 10.1007/978-3-030-72432-0_2

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  • Effects of MgCl2 and NaCl on Si-Thermic Reduction of MgO in Recycle of Mg-air Battery

    Atsushi Hayashida, Toshihide Takenaka, Taiki Morishige

    Minerals, Metals and Materials Series   267 - 273   2021

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Springer Science and Business Media Deutschland GmbH  

    The effects of the chlorine content used as electrolyte should be controlled in the recycle process of Mg-air battery. The influence of MgCl2 and NaCl in Si-thermic reduction of MgO has been studied in this study. The mixture of MgO with MgCl2 or NaCl was reduced by metallic Si at 1150 °C for 3 h, and the reduction rate was estimated. The reduction rate without MgCl2 or NaCl addition was about 55% under our reduction condition, and 1 mol% addition of MgCl2 rarely affected the reduction rate. However, the reduction rate decreased with added amount of MgCl2, and became about 15% in 10 mol% addition. Even 1 mol% addition of NaCl worsened the reduction rate, and the reduction rate decreased with the addition amount. It is confirmed that the chlorine should be removed before Si-thermic reduction in the recycle of Mg-air battery.

    DOI: 10.1007/978-3-030-72432-0_26

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  • Anodic Behavior of MoSi2 in Molten MgCl2-NaCl-CaCl2 Containing Oxide Ions Reviewed

    Takamasa Miyoshi, Taiki Morishige, Toshihide Takenaka

    ECS Transactions   Vol. 98, No. 10, pp.253-260   2020

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  • Al electrodeposition in molten CaCl2 with various calcium aluminates Reviewed

    Yuta Iwai, Taiki Morishige, Toshihide Takenaka

    ECS Transactions   Vol. 98, No. 10 pp. 333-340   2020

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  • The Effect of Vibration Condition for Magnesium Dry Gravity Sorting by Vibrating Particulate Bed Reviewed

    Shingo Itoh, Keigo Tsujita, Taiki Morishige, Toshihide Takenaka

    Materials Science Forum   Vol. 941, pp. 1535-1539   2018

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  • Relationship between Microstructure and Exfoliation Corrosion in Mg-14mass%Li-3mass%Al Cold-Rolled Alloy Reviewed

    Yuki Sekiguchi, Taiki Morishige, Takayuki Goto, Eiji Nakamura, Toshihide Takenaka

    Materials Science Forum   Vol. 941, pp. 1743-1747   2018

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  • Dependence of reduction behavior of Ti in molten CaCl2 on various calcium titanate Reviewed

    Haruka Okada, Kakeru Shimokawa, Taiki Morishige, Toshihide Takenaka

    Materials Transactions   59 ( 4 )   690 - 693   2018

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japan Institute of Metals (JIM)  

    The change in TiO2 solubility in molten CaCl2 at 1573 K with CaO addition was studied to clarify the influence of CaO on TiO2 dissolution. The solubility of TiO2 in molten CaCl2 remarkably enlarged with CaO addition, which suggests that a titanate ion (TixOy Z1) was preferentially formed in it. The cathodic behavior in molten CaCl2 containing various species of calcium titanate at 13731573 K was investigated by cyclic voltammetry, and electrodeposition of Ti metal was attempted by potentio-static electrolysis. The reduction behavior was affected by the species of calcium titanate, and the components in the deposit changed consequently. These results indicate that the reduction behavior of Ti was strongly influenced by the species of titanate ion, and that the bath consisting of Ca3Ti2O7 is found suitable.

    DOI: 10.2320/matertrans.MBW201702

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  • Effect of Voltage on Mg-Li-Al allopy Anodic Oxide Film Reviewed

    Naoya Miyakita, Natsuki Tanigaki, Taiki Morishige, Toshihide Takenaka

    Materials Science Forum   Vol. 941, pp. 1194-1197   2018

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  • Influence of Molar Ratio of CaO to TiO2 on Ti Electrodeposition in Molten CaCl2 Reviewed

    Haruka Okada, Maito Murata, Taiki Morishige, Toshihide Takenaka

    ECS Transactions   Vol. 86, No. 14, pp. 117-122   2018

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  • Electrodeposition of Si in Molten CaCl2 above 1300K Reviewed

    Toshihide Takenaka, Ryoya Shimokawa, Haruka Okada, Taiki Morishige

    ECS Transactions   Vol. 86, No. 14, pp. 29-35   2018

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  • The Relationship between Mg Content and Extra-Hardening in Ultrafine Grained Al-Mg Alloy by SPD Reviewed

    Yuto Suzuki, Yuichi Shiono, Taiki Morishige, Toshihide Takenaka

    Materials Science Forum   Vol. 941, pp. 1173-1177   2018

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  • Unique Metal Fog Generation in LiCl-KCl Melt Reviewed

    Toshihide Takenaka, Shogo Akimura, Taiki Morishige

    Electrochemistry   Vol. 86, No. 4 pp.179-183   2018

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  • Effect of Zn Existence on Mg Corrosion Due to Cu Reviewed

    Hiroaki Ishimaru, Taiki Morishige, Toshihide Takenaka

    ECS Transactions   Vol. 75, No. 26, p. 1-5   2017.1

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  • Dissolution of Calcium Titanate in Calcium Chloride Melt and Its Application to Titanium Electrolysis Reviewed

    Toshihide Takenaka, Kakeru Shimokawa, Kazuyoshi Nishikawa, Haruka Okada, Taiki Morishige

    MATERIALS TRANSACTIONS   58 ( 3 )   350 - 354   2017

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    The solubility of calcium titanate in CaCl2 melt was investigated above 1373 K, and electrodeposition of Ti metal in the melt was attempted. Many pits were formed on the surface of sintered CaTiO3 compact by the immersion in CaCl2 melt above 1373 K. The weight of the compact decreased with the increase in the immersion time, and the decrease got faster with the increase in temperature. Cathodic current in cyclic voltammetry increased with the addition of CaTiO3 powder in the bath, and the increase in the cathodic currents depended on the bath temperature and the added amount of CaTiO3. From the results by the electrochemical measurement, the solubilities of CaTiO3 in CaCl2 melt were estimated about 7 mol% at 1573 K, and less than 1 mol% at 1373 K. Metallic Ti was detected by XRD analysis in the electrodeposit obtained by potentio-static electrolysis in the bath containing CaTiO3 above 1373 K, but the amount of Ti metal seemed a little. The similar results were obtained in CaCl2 melt containing Ca3Ti2O7 though the detailed study has not been completed. It was concluded that calcium titanate was soluble in molten CaCl2 above 1373 K, and that the CaCl2 bath containing calcium titanate could be applied to Ti electrolysis.

    DOI: 10.2320/matertrans.MK201615

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  • Effect of composition and temperature on current efficiency for aluminium electrolysis from cryolite-based molten alumina electrolytes

    T. Morishige, G. M. Haarberg, H. Gudbrandsen, E. Skybakmoen, A. Solheim, T. Takenaka

    ECS Transactions   77 ( 11 )   997 - 1002   2017

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Electrochemical Society Inc.  

    The current efficiency (CE) for aluminium electrolysis in modern cells can be as high as 96 %. The main reason for loss in current efficiency is the so-called back reaction between dissolved metal and the anode product of CO2 Decreasing temperature of the cell may give higher current efficiency. However, low superheat may cause solidification of melt. A laboratory cell to determine the current efficiency was recently modified to obtain more reliable results. Electrolysis was performed at constant current density and the current efficiency was determined from the weight of deposited aluminium. Effects of electrolyte composition by addition of LiF and temperature were studied. The loss in current efficiency is strongly related to the content of dissolved metal in the electrolyte. The effect of LiF addition on the current efficiency was discussed in this study.

    DOI: 10.1149/07711.0997ecst

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  • Influence of cathode potential on Ti electrodeposition in molten fluoride

    Kazuyoshi Nishikawa, Sawada Humiya, Taiki Morishige, Toshihide Takenaka

    MOLTEN SALTS AND IONIC LIQUIDS 20   75 ( 15 )   199 - 206   2016

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELECTROCHEMICAL SOC INC  

    The electrolysis condition to obtain Ti metal in a CaF2-MgF2 with CaO and TiO2 has been studied at 1573K. It was shown by cyclic voltammetry that cathodic current increased below 0.8V ( vs. Mg/Mg2+) with CaO and TiO2 addition and that three reduction steps of Ti was suggested. The particles containing Ti were obtained by potentio-static electrolysis; only Ti oxide particles were detected by the electrolysis above 0.5V, while Ti metal particles did by the electrolysis below 0.4V. This result indicates that Ti metal can be electrodeposited below 0.4V (vs. Mg/Mg2+).

    DOI: 10.1149/07515.0199ecst

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  • Effect of electrode shape on lithium metal fog in LiCl-KCl

    Shogo Akimura, Taiki Morishige, Toshihide Takenaka

    MOLTEN SALTS AND IONIC LIQUIDS 20   75 ( 15 )   233 - 237   2016

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELECTROCHEMICAL SOC INC  

    The so-called metal fog sometimes formed during the molten salt electrolysis. In this paper, the effect of the surface shape of electrode on the metal fog formation was investigated in LiCl-KCl. Cyclic voltammetry and potentiostatic electrolysis were carried out at Mo wire electrode with/without screw cutting. The dark blue metal fog was formed at both types of electrodes, while the gray metal fog was generated only at the screw-cut electrode. The gray fog formation also depended on the diameter of the electrode; the formation was intenser at a small electrode than at a large electrode. It is concluded that the shape of electrode strongly affects the gray metal fog formation, and it is suggested that the current concentration at the edge causes the formation.

    DOI: 10.1149/07515.0233ecst

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  • Effect of Al Composition on the Corrosion Resistance of Mg-14 mass% Li System Alloy

    Taiki Morishige, Yutaro Obata, Takayuki Goto, Tomoki Fukagawa, Eiji Nakamura, Toshihide Takenaka

    MATERIALS TRANSACTIONS   57 ( 10 )   1853 - 1856   2016

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Mg-Li system alloys have poor corrosion properties, especially cold-rolled sheet leads to exfoliation corrosion as a result of long-term immersion test. Addition of aluminum element to Mg-14 mass% Li alloy could be suppressed the occurrence of exfoliation corrosion. However, excess addition of aluminum to Mg-14 mass% Li alloy causes the degradation of corrosion resistance. In this study, the composition of aluminum in Mg-14 mass% Li was optimized to improve the corrosion property. 3 mass% of Al addition could be suppressed the corrosion rate because enough aluminum element dissolved into matrix and precipitation of the second phase was inhibited.

    DOI: 10.2320/matertrans.M2016247

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  • Magnesium Sorting by Vibrating Particulate Bed from Mixed Metal Scrap

    Taiki Morishige, Keigo Tsujita, Soshiro Murasa, Toshihide Takenaka

    MATERIALS TRANSACTIONS   56 ( 10 )   146 - 148   2015.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    As increasing the demand of Mg alloys, recycling of these alloys require for securing a metallic resource and energy conservation. A commercial metal scrap includes other structural materials such as iron, copper and aluminum alloys. These metal elements deteriorate mechanical properties or corrosion properties of Mg alloys. Therefore, these different materials were possibly removed from Mg scrap during recycling process. The separation of Al and Mg materials has difficulty except for the gravity separation. However, there is a limited difference in density between Mg and Al. In this study, Mg recovery from mixed metal scrap was attempted by dry gravity separation using solid particulate vibrating bed. Mg separation with high recovery ratio was achieved by adjusting the density of the particulate bed. It was suggested that the bulk density of the particulate bed affected the behavior of separation materials for the favorable recovery.

    DOI: 10.2320/matertrans.M2015226

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  • Removal of Impurity Fe from Mg-3 mass% Al Alloy Melt by CO2 Injection

    Taiki Morishige, Kazuchika Kurino, Toshihide Takenaka

    MATERIALS TRANSACTIONS   56 ( 3 )   454 - 456   2015

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    The purification process is required for recycling Mg process. Selective impurity removal has an efficient purification process in the purity level of commercial Mg metal and alloys. Especially, iron impurity deteriorates the corrosion resistance of Mg alloys. Carbon addition to Mg-3 mass% Al alloy melt is an effective method for the removal of iron impurity by the formation of Fe-Al-C compounds. In this study, gas injection of carbon dioxide (CO2) into Mg alloy melt as the method of carbon addition was investigated for the separation of iron compounds. Carbon dioxide was decomposed by Mg melt and carbon substance affected the formation of iron carbide in the melt. Magnesium oxide and Fe-Al-C compound were formed in the melt slag and floated to the top of the solidified Mg-3 mass% Al alloy.

    DOI: 10.2320/matertrans.MBW201407

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  • Effect of Impurity Fe Concentration on the Corrosion Behavior of Mg-14 mass%Li-1 mass%Al Alloy

    Taiki Morishige, Kumiko Ueno, Masahiro Okano, Takayuki Goto, Eiji Nakamura, Toshihide Takenaka

    MATERIALS TRANSACTIONS   55 ( 9 )   1506 - 1509   2014.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Mg-Li system alloys with over 11 mass% Li have an excellent cold-workability in Mg alloys due to the bcc-structured crystal system. However this system alloys have poor corrosion resistance caused by Li solid-solution alloy. The corrosion resistance of conventional hcp-Mg alloys is influenced by the composition of impurity elements. Particularly, minute iron element deteriorates the corrosion resistance of Mg alloy and there is a threshold concentration on the corrosion rate in Mg alloys. In this study, the effect of iron element on the corrosion resistance of Mg-Li alloy was investigated by addition of iron. The corrosion resistance of Mg-Li with no Fe addition was higher than conventional Mg alloy. The corrosion rate of Mg-Li alloy increased with increasing iron concentration. However, there is no threshold iron concentration affected to the corrosion resistance on Mg-Li alloy.

    DOI: 10.2320/matertrans.MAW201405

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  • Cathodic Phenomena in Li Electrolysis in LiCl-KCl Melt

    T. Takenaka, T. Morishige, M. Umehara

    Molten Salts Chemistry and Technology   9781118448731   143 - 148   2014.6

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    Language:English   Publishing type:Part of collection (book)   Publisher:Wiley Blackwell  

    The cathodic phenomena in Li electrolysis in LiCl-KCl eutectic melt were studied by means of in situ visual observation linked with electrochemical measurement. It was shown that the so-called metal fog was observed even in Li electrolysis under particular conditions. The results in this study suggested the phenomenon in Li electrolysis seemed different from those of Na and Ca electrolysis. The cathodic reaction of H2 bubble generation due to residual moisture in the bath was evaluated from this link-view, and it was indicated that the reduction of the residual moisture strongly influenced the efficiency of Li electrolysis. The link between the in situ visual observation and the electrochemical response was shown helpful for better understanding of electrochemical investigation in a molten salt bath.

    DOI: 10.1002/9781118448847.ch2d

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  • Electrochemical Behavior of Ti in Molten Fluoride-Oxide System

    Y. Yamanaka, T. Morishige, T. Takenaka

    MOLTEN SALTS AND IONIC LIQUIDS 19   64 ( 4 )   275 - 283   2014

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELECTROCHEMICAL SOC INC  

    The cathodic reaction of Ti has been studied in a CaF2-MgF2 bath with CaO and TiO2 at 1373K. Cyclic voltammograms were measured in the baths of various compositions, and the dependence of the cathodic reaction of Ti on the bath composition was discussed. With reference to the results of the cyclic voltammetry, Ti metal deposition by potentio-static electrolysis was attempted. It was shown that the reduction sequence of Ti consisted of three steps, and Ti metal was deposited under the suitable condition. The cathodic behavior of Ti was influenced by the molar ratio of TiO2 to CaO in the melt. Considering the previous results of Ti electrolysis by using DC-ESR unit, it is strongly suggested that a binuclear complex ion of Ti with O, such as Ti2O76-, affects the reduction sequence of Ti in CaF2-CaO-TiO2 and CaF2-MgF2-CaO-TiO2 baths.

    DOI: 10.1149/06404.0275ecst

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  • Friction Stir Processing Effects on Hardness of Cast Al-Cu Alloys Reviewed

    Morishige Taiki, Tsujikawa Masato, Higashi Kenji

    Journal of Japan Foundry Engineering Society   Vol. 85, No. 12, pp. 837-842 ( 12 )   837 - 842   2013.10

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    Language:Japanese   Publisher:Japan Foundry Engineering Society  

    <p>  The effects of Friction Stir Processing (FSP) on the hardness of Al-Cu binary alloys with various copper contents up to 9mass%Cu were investigated. Prepared Al-Cu samples were divided in two groups. Samples in one group were used as cast sample plate. Samples in the other group were annealed at 673K for 108ks. The hardness of as cast samples increased with increasing copper content before FSP treatment. The hardness of the annealed samples increased in the same way as the as cast sample at low copper ranges up to 5mass%Cu. At higher copper content ranges from Al-5%Cu, the rate of hardness increment of annealed samples however slowed down before FSP. Sample plates were treated by FSP, and microstructure and hardness were measured. Samples containing less than 4%Cu including pure aluminum showed hardness increment by 10HV after FSP regardless of heat treatment. For as-cast series specimens however, the FSP treatment never increased the hardness in copper content ranges from 5mass% to 9mass%. On the other hand, annealed samples were slightly hardened by FSP. This is because the annealed samples have a weaker network of harder phase than as-cast samples, and the breakdown of such networks and distribution of the fragments weaken the material of as-cast samples.</p>

    DOI: 10.11279/jfes.85.837

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  • Exfoliation Corrosion Behavior of Cold-Rolled Mg-14 mass% Li-1 mass% Al Alloy in NaCl Solution

    Taiki Morishige, Hirokazu Doi, Takayuki Goto, Eiji Nakamura, Toshihide Takenaka

    MATERIALS TRANSACTIONS   54 ( 9 )   1863 - 1866   2013

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Cold-rolled Mg-Li system alloys represent the exfoliation corrosion on the surface of the longitudinal and the transverse sections. In this study, the origination of the exfoliation corrosion of the cold-rolled Mg-Li alloy was clarified. In the initial stage of the corrosion, the oxide film formed immediately on the surface of each section, and then the film destruction with a remarkable bubble generation was observed in a certain spot. There were microcracks on the trace of the film destruction along the grain boundary. The corrosion resistance in the annealed specimen was more than that in the as-rolled specimen because the microstructure of the as-rolled specimen has elongated and thinned grains by severe cold rolling. The exfoliation corrosion was not observed in the annealed specimen, because the annealed specimen has homogeneous equiaxial grains. The successive film destruction in annealed specimen progressed along the grain boundary to random direction. Moreover, the initiation time of the bubble generation was delayed in the annealed specimen.

    DOI: 10.2320/matertrans.MAW201301

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  • 摩擦攪拌接合法によるアルミニウムと鋼の異材接合技術 Reviewed

    田中 努, 平田 智丈, 森重 大樹, 四宮 徳章, 白川 信彦

    軽金属溶接   第50巻 第3号 93-100   2012.3

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  • Anodic Reactions on Some Materials in LiCl-KCl Melt

    T. Takenaka, M. Umehara, D. Araki, T. Morishige

    MOLTEN SALTS AND IONIC LIQUIDS 18   50 ( 11 )   127 - 134   2012

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELECTROCHEMICAL SOC INC  

    The anodic reactions on some materials in LiCl-KCl eutectic melt have been investigated. Palladium and Mo were dissolved though Mo showed passivation behavior. In the melt including Li2O, O-2 gas generation occurred at both metal anodes along with their anodic dissolution. At the graphite anode, some anodic reactions besides the Cl-2 gas generation reaction were observed in the melt with Li2O. The visual observation and the weight change of the anode indicated that the anodic reaction without gas generation and the electrode consumption preceded the CO2 gas generation. The potential of the CO2 gas generation reaction on graphite looked more positive than that of the O-2 gas generation on Pd and Mo, which suggested the overpotential of the CO2 generation reaction on graphite was rather large in the melt.

    DOI: 10.1149/05011.0127ecst

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  • 純アルミニウムと軟鋼の異種金属摩擦攪拌接合材の接合界面における金属間化合物形成機構 Reviewed

    田中 努, 森重 大樹, 平田 智丈

    溶接学会論文集   第29巻 第2号 p.101-106   2011.6

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  • Effect of Mg content on the minimum grain size of Al-Mg alloys obtained by friction stir processing

    Taiki Morishige, Tomotake Hirata, Tokuteru Uesugi, Yorinobu Takigawa, Masato Tsujikawa, Kenji Higashi

    SCRIPTA MATERIALIA   64 ( 4 )   355 - 358   2011.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Friction stir processing (FSP) is one of the severe plastic deformation processes that have been developed to improve the mechanical properties of both metals and alloys by producing an ultrafine-grained structure. In this study, it was used to realize the minimum grain size in Al-Mg alloys. The results indicate that the grain size in Al-Mg alloy decreases with increasing Mg content because of the influence of stacking fault energy in the Al-Mg alloy. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.scriptamat.2010.10.033

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  • INFLUENCES OF ALLOYING ELEMENTS ON GRAIN SIZES IN FRICTION STIR PROCESSED PURE ALUMINUM AND ALUMINUM ALLOYS Reviewed

    Tomotake Hirata, Taiki Morishige, Masato Tsujikawa, Kenji Higashi

    TMS2011 SUPPLEMENTAL PROCEEDINGS, VOL 3: GENERAL PAPER SELECTIONS   677 - 684   2011

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:JOHN WILEY & SONS  

    A friction stir processing (FSP) technique has been developed for use with aluminum and magnesium alloys. The microstructure was evolved into fine grains by the dynamic recrystallization during FSP. In this study, FSP was used to pure aluminum and aluminum alloys and the influence of alloying element on the grain size was investigated. In addition, the relationship between the grain size and the Zener-Hollomon parameter was investigated. There was observed difference in grain size between these materials. The recrystallized grain of FSP-ed ultra-high-purity (99.999%) aluminum was particularly large, compared to the grain sizes of other materials, when subjected to the same processing conditions. In contrast, grain sizes decreased with an increase in the Zener-Hollomon parameter in all materials. However, the grain size reached a certain minimum value at high-strain-rates of processing. Compared to other processed aluminum materials, the minimum grain size was found for each material.

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  • Comprehensive analysis of minimum grain size in pure aluminum using friction stir processing

    Taiki Morishige, Tomotake Hirata, Masato Tsujikawa, Kenji Higashi

    MATERIALS LETTERS   64 ( 17 )   1905 - 1908   2010.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    A friction stir processing (FSP) technique has been developed for use with aluminum and magnesium alloys, with the goal of high-strain-rate processing. In this study, we treat the microstructures of aluminum samples, of three levels of purity, manipulating their grain sizes, making them finer, using FSP. Grain sizes decreased with an increase in the Zener-Hollomon parameter, at all purity levels. However, the recrystallized grain of FSP-ed ultra-high-purity (99.999%) aluminum was particularly large, compared to the grain sizes of lower-purity (99% and 99.99%) aluminum, when subjected to the same processing conditions. The grain size reached a certain minimum value at high-strain-rates of processing, which we report for each purity level herein. (C) 2010 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2010.06.003

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  • Comprehensive analysis of joint strength for dissimilar friction stir welds of mild steel to aluminum alloys Reviewed

    Tsutomu Tanaka, Taiki Morishige, Tomotake Hirata

    SCRIPTA MATERIALIA   61 ( 7 )   756 - 759   2009.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Post-weld properties of dissimilar friction stir welds of mild steel/A7075-T6 aluminum alloy were investigated. The joint strength increased with reduction in thickness of the intermetallic compound at the weld interface. During tensile tests of the composite weld, no weld failed in the aluminum base metal. Comprehensive analysis using the heat input parameter showed that the apparent interface strength between the steel and aluminum was lower than the joint strength of the friction-stir-welded A7075-T6 alloy. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.scriptamat.2009.06.022

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  • Thin Protective Aluminum Layer on Mg-Li Alloy by Plasma Spraying and Cold Rolling Reviewed

    Sachio Oki, Masato Tsujikawa, Taiki Morishige, Masaichiro Kamita

    PLASMA PROCESSES AND POLYMERS   6   S954 - S957   2009

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-V C H VERLAG GMBH  

    Formation of a protective thin surface of pure aluminum on Mg-14mass%Li alloy by plasma thermal spraying and the cold rolling was investigated. An Mg-14mass%Li-1mass%Al alloy ingot was melted and cast in a pressurized argon atmosphere. After homogeneous heat treatment, the ingot was rolled to 3 mm-thick plate with a reduction ratio of 98%. The plate specimens were annealed again. Plasma sprayings of pure aluminum were carried out with various conditions after grit blasting. The coated layer thickness was about 100 mu m. There was slight increase in temperature during spraying on substrates. The first pass of rolling was carried out at 250 degrees C; then several cold rolling passes were processed to reduce the entire thickness up to 90% in reduction ratio of the sprayed specimens&apos; thickness. It was found that the determining factor for sound rolled sheet without separation of aluminum coating was the maximum temperature of the substrate at plasma processing. There were no separation, for specimen heated in the temperature range between 300 and 400 degrees C during thermal spraying, at rolling up to 90% in total reduction ratio. Sectional observation revealed a continuous thin aluminum layer adhered on the Mg-14mass%Li alloy.

    DOI: 10.1002/ppap.200932408

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  • Surface Modification of Al- and Mg- castings by Friction Stir Processing Reviewed

    Taiki Morishige, Masato Tsujikawa, Makoto Hino, Tomotake Hirata, Kenji Higashi, Takayuki Takasugi

    熱処理   Vol. 49, Special Issue 1, pp. 177-180   2009

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  • Microstructural modification of cast Mg alloys by friction stir processing

    T. Morishige, M. Tsujikawa, M. Hino, T. Hirata, S. Oki, K. Higashi

    INTERNATIONAL JOURNAL OF CAST METALS RESEARCH   21 ( 1-4 )   109 - 113   2008.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:MANEY PUBLISHING  

    Cast Mg alloys were processed using friction stir processing (FSP) to acquire a fine grained structure and high strength. Actually, FSP is a novel grain refinement method for light metal alloys. Using FSP, a cast microstructure with coarse grain size was refined to equiaxial fine grain through dynamic recrystallisation; second phase particles were finely dispersed by FSP. Moreover, FSP is effective to eliminate cast defects such as microshrinkages or porosities. Commercial die cast Mg alloy (AZ91D) and high strength Mg-Y-Zn alloy plates were prepared for FSP. Heat input using a rotational tool during FSP closely affected the microstructure in the stirred zone. Actually, FSP with lower heat input produced a finer grain size and higher hardness. Changes in the friction stir processed microstructures affecting mechanical properties were not only grain refinement, but also second phase particle distributions. Results show that alloys with high hardness by FSP have finely dispersed second phase particles without dissolution during FSP.

    DOI: 10.1179/136404608X361774

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  • Dissimilar welding of Al and Mg alloys by FSW

    Taiki Morishige, Atsushi Kawaguchi, Masato Tsujikawa, Makoto Hino, Tomotake Hirata, Kenji Higashi

    MATERIALS TRANSACTIONS   49 ( 5 )   1129 - 1131   2008.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Microstructures and mechanical properties of dissimilar welding joint between Al alloy and Mg alloy by Friction Stir Welding (FSW) were investigated in comparison with laser welding of the same combination. Dissimilar joint of At and Mg alloy by laser welding was very brittle because of building up Mg17Al12 inter metallic compounds in fusion zone. On the other hand, FSW is anticipated to welding dissimilar alloys with enough joint strength because it is a solid-state process without melting. In this paper, FSW was carried out to make dissimilar butt joints of Al alloy and AZ31 magnesium alloy with various tool rotational speed and welding speed. These joints showed higher hardness in their stir zones than that of parent AZ31 alloy because of Mg-Al inter metallic compound formation. However, the hardness of stir zone was lower than that of fusion zone of laser welding, and was changed with the welding parameters of tool rotational speed and welding speed (i.e. heat input ratio of FSW). The optimum welding conditions of Mg and Al dissimilar FSW joint and the influence of inter metallic compound distribution with mixing of materials in stir zone were discussed.

    DOI: 10.2320/matertrans.MC200768

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  • Microstructural evolution of friction stir processed cast Mg-5.9 mass % Y-2.6 mass % Zn alloy in high temperature deformation Reviewed

    M. Tsujikawa, S. W. Chung, T. Morishige, L. F. Chiang, Y. Takigawa, S. Oki, K. Higashi

    MATERIALS TRANSACTIONS   48 ( 3 )   618 - 621   2007.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Cast Mg-Y-2-Zn-1 alloy was friction stir (FS) processed to obtain fine grain structure. Then the elevated temperature tensile tests were carried out to investigate the deformation behavior of the FS processed alloy. The starting structure for FS processing was coarse dendritic microstructure (secondary dendrite arm spacing ca. 75 mu m) with a plate-like second phase, which developed from inter-dendritic eutectic pockets after homogenization heat treatment. The alpha-Mg matrix and second phases were broken mechanically and distributed homogeneously by FS processing. The refined grain size at the fully stirred zone had the average size of ca. 2.0 mu m. Different deformation behavior occurred as a result of varying microstructural evolution according to temperatures (623 K and 723 K).

    DOI: 10.2320/matertrans.48.618

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  • Mechanical properties on the friction stir processed cast Mg-1at.%Zn-2at.%Y alloy Reviewed

    S. W. Chung, M. Tsujikawa, T. Morishige, L. F. Chiang, Y. Takigawa, S. Oki, K. Higashi

    MAGNESIUM TECHNOLOGY 2007   299 - +   2007

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MINERALS, METALS & MATERIALS SOC  

    Friction stir processing (FSP) was carried out for cast Mg-1at.%Zn-2at.%Y alloy. Bulk fine-grained microstructure including second phase was obtained, Lamella structure was developed from quasi-crystal by heat treatment. At room temperature, FSP-ed Mg-1at.%Zn-2at.%Y alloy showed higher hardness when compared to those made by other processes. Main deformation mechanism was controlled by the dislocation-climb creep (n similar to 4.5) in the range of strain rates 10-3 to 10-1 (s-1) and temperature 623K to 723K. Ductility was up to 240 % at strain rate of 10-3 (s-1) arid at 723K.

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Books

  • Cathodic Phenomena in Li Electrolysis in LiCl-KCl Melt

    Toshihide Takenaka, Taiki Morishige, Masaki Umehara( Role: Joint author)

    Molten Salts Chemistry and Technology  2014 

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  • Effect of Mg content on the minimum grain size of Al-Mg alloys obtained by friction stir processing

    Taiki Morishige, Tomotake Hirata, Tokuteru Uesugi, Yorinobu Takigawa, Masato Tsujikawa, Kenji Higashi

    SCRIPTA MATERIALIA   64 ( 4 )   355 - 358   2011.2

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    Language:English   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Friction stir processing (FSP) is one of the severe plastic deformation processes that have been developed to improve the mechanical properties of both metals and alloys by producing an ultrafine-grained structure. In this study, it was used to realize the minimum grain size in Al-Mg alloys. The results indicate that the grain size in Al-Mg alloy decreases with increasing Mg content because of the influence of stacking fault energy in the Al-Mg alloy. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.scriptamat.2010.10.033

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  • Comprehensive analysis of minimum grain size in pure aluminum using friction stir processing

    Taiki Morishige, Tomotake Hirata, Masato Tsujikawa, Kenji Higashi

    MATERIALS LETTERS   64 ( 17 )   1905 - 1908   2010.9

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    Language:English   Publisher:ELSEVIER SCIENCE BV  

    A friction stir processing (FSP) technique has been developed for use with aluminum and magnesium alloys, with the goal of high-strain-rate processing. In this study, we treat the microstructures of aluminum samples, of three levels of purity, manipulating their grain sizes, making them finer, using FSP. Grain sizes decreased with an increase in the Zener-Hollomon parameter, at all purity levels. However, the recrystallized grain of FSP-ed ultra-high-purity (99.999%) aluminum was particularly large, compared to the grain sizes of lower-purity (99% and 99.99%) aluminum, when subjected to the same processing conditions. The grain size reached a certain minimum value at high-strain-rates of processing, which we report for each purity level herein. (C) 2010 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2010.06.003

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  • Microstructural modification of cast Mg alloys by friction stir processing

    T. Morishige, M. Tsujikawa, M. Hino, T. Hirata, S. Oki, K. Higashi

    INTERNATIONAL JOURNAL OF CAST METALS RESEARCH   21 ( 1-4 )   109 - 113   2008.8

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    Language:English   Publisher:MANEY PUBLISHING  

    Cast Mg alloys were processed using friction stir processing (FSP) to acquire a fine grained structure and high strength. Actually, FSP is a novel grain refinement method for light metal alloys. Using FSP, a cast microstructure with coarse grain size was refined to equiaxial fine grain through dynamic recrystallisation; second phase particles were finely dispersed by FSP. Moreover, FSP is effective to eliminate cast defects such as microshrinkages or porosities. Commercial die cast Mg alloy (AZ91D) and high strength Mg-Y-Zn alloy plates were prepared for FSP. Heat input using a rotational tool during FSP closely affected the microstructure in the stirred zone. Actually, FSP with lower heat input produced a finer grain size and higher hardness. Changes in the friction stir processed microstructures affecting mechanical properties were not only grain refinement, but also second phase particle distributions. Results show that alloys with high hardness by FSP have finely dispersed second phase particles without dissolution during FSP.

    DOI: 10.1179/136404608X361774

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  • Dissimilar welding of Al and Mg alloys by FSW

    Taiki Morishige, Atsushi Kawaguchi, Masato Tsujikawa, Makoto Hino, Tomotake Hirata, Kenji Higashi

    MATERIALS TRANSACTIONS   49 ( 5 )   1129 - 1131   2008.5

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    Language:English   Publisher:JAPAN INST METALS  

    Microstructures and mechanical properties of dissimilar welding joint between Al alloy and Mg alloy by Friction Stir Welding (FSW) were investigated in comparison with laser welding of the same combination. Dissimilar joint of At and Mg alloy by laser welding was very brittle because of building up Mg17Al12 inter metallic compounds in fusion zone. On the other hand, FSW is anticipated to welding dissimilar alloys with enough joint strength because it is a solid-state process without melting. In this paper, FSW was carried out to make dissimilar butt joints of Al alloy and AZ31 magnesium alloy with various tool rotational speed and welding speed. These joints showed higher hardness in their stir zones than that of parent AZ31 alloy because of Mg-Al inter metallic compound formation. However, the hardness of stir zone was lower than that of fusion zone of laser welding, and was changed with the welding parameters of tool rotational speed and welding speed (i.e. heat input ratio of FSW). The optimum welding conditions of Mg and Al dissimilar FSW joint and the influence of inter metallic compound distribution with mixing of materials in stir zone were discussed.

    DOI: 10.2320/matertrans.MC200768

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  • Strengthening of cast Mg alloys by friction stir processing

    Taiki Morishige, Masato Tsujikawa, Sachio Oki, Tornotake Hirata, Kenji Higashi

    MAGNESIUM TECHNOLOGY 2008   005   221 - +   2008

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    Language:English   Publisher:MINERALS, METALS & MATERIALS SOC  

    Cast magnesium alloys were processed by friction stir processing (FSP) to acquire fine grain and high strength. FSP is a novel grain refinement method for light metal alloys. By using FSP, cast microstructures were refined by dynamic recrystallization (DRX) and second phase particles could be finely dispersed by FSP. Moreover, FSP is effective process to eliminate cast defects like micro porosities. Thick plate of commercial Mg alloy for die-casting AZ91D or Mg-Y-Zn alloys of two different chemical compositions have been prepared for FSP. Changes in the FSP-ed microstructures that affect mechanical properties were not only grain size refinement, but also the distributions of second phase particles. As-cast Mg-2at.%Y-2at.%Zn (Mg-6.7wt.%Y-5.0wt%Zn) alloy, differs from Mg-2at.%Y-1at.%Zn (Mg-6.8wt.%Y-2.5wt.%Zn), has icosahedral quasi-crystalline phase in grain boundaries. It has higher elevated temperature stability than inter-metallic compound of Al12Mg17. The distribution of fine second phase particles and mechanical properties were discussed.

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  • Grain Refinement of Mg-Y-Zn alloy by Friction Stir Processing

    T. Morishige, M. Tsujikawa, S. Oki, M. Kamita, S. W. Chung, K. Higashi

    ADVANCED MATERIALS AND PROCESSING   26-28   465 - +   2007

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    Language:English   Publisher:TRANS TECH PUBLICATIONS LTD  

    Grain refinement of magnesium alloy by Friction Stir Processing (FSP) was investigated. It is assumed that dynamic recrystallization (DRX) is occurred by frictional heat and plastic flow during FSP. This process is the effective method of the grain refinement for light metals. In this study, FSP was conducted to cast Mg alloys for and the difference of the grain refinement by DRX in these alloys was examined. As a result, in comparison with commercial Mg-Al-Zn alloy and Mg-Y-Zn alloy have finer microstructure. The grain size of FSP-ed Mg-Y-Zn alloy was similar to 1.7 [mu m], however, that of AZ31 alloy was 20 similar to 30 [mu m].

    DOI: 10.4028/www.scientific.net/AMR.26-28.465

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  • Microstructure of Friction stir processed Mg-Y-Zn alloy

    T. Morishige, M. Tsujikawa, S. W. Chung, S. OKi, K. Higashi

    RECRYSTALLIZATION AND GRAIN GROWTH III, PTS 1 AND 2   558-559   777 - +   2007

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    Language:English   Publisher:TRANS TECH PUBLICATIONS LTD  

    Friction stir processing (FSP) is the effective method of the grain refinement for light metals. The aim of this Study is to acquire the fine grained bulk Mg-Y-Zn alloy by ingot metallurgy route much lower in cost. Such bulk alloy can be formed by the superplastic forging. The microstructure of as-cast Mg-Y-Zn alloy was dendrite. The dendrite arm spacing was 72.5 [mu m], and there are the lamellar structures in it. FSP was conducted on allover the plate of Mg-Y-Zn alloy for both surfaces by the rotational tool with FSW machine. The stirring passes were shifted half of the probe diameter every execution. The dendrite structures disappeared after FSP, but the lamellar structure could be observed by TEM. The matrix became recrystallized fine grain, and interdendritic second phase particles were dispersed in the grain boundaries. By using FSP, cast Mg-Y-Zn alloy could have fine-grained. This result compared to this material produced by equal channel angular extrusion (ECAE) or rapid-solidified powder metallurgy (RS P/M). As the result, as-FSPed material has the higher hardness than materials produced by the other processes at the similar grain size.

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  • Friction Stir Processing of Cast Mg-Y-Zn Alloy

    T. Morishige, M. Tsujikawa, S. Oki, M. Kamita, S. W. Chung, K. Higashi

    THERMEC 2006 SUPPLEMENT   15-17   369 - 374   2007

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    Language:English   Publisher:TRANS TECH PUBLICATIONS LTD  

    A high strength at room temperature and at high temperature was reported for the extremely fine-grained RS P/M Mg-2at%Y-1at%Zn (Mg-6.8mass%Y-2.5mass%Zn) alloy. This property was attributed to the fine grain size. However, such alloys have very poor productivity. Therefore, they are far from from practical applications.
    The aim of this study is to acquire the fine-grained bulk Mg-Y-Zn alloy by ingot metallurgy route much lower in cost. Friction-Stir-Processing (FSP) was performed on this alloy ingot, and the mechanical properties and the microstructures were examined. FSP was conducted on allover the plate of this alloy for both surfaces by the rotational tool with FSW machine. The stirring passes were shifted half of the probe diameter every execution.
    The microstructure of as-cast material was dendrite. The dendrite are spacing was 72.5 [mu m], and there are the lamellar structures in it. The dendrite structures disappeared after FSP, but the lamellar structure could be observed by TEM. the grain size of FSP materials were measured as ca. 1 mu m by TEM micrographs.

    DOI: 10.4028/www.scientific.net/AMR.15-17.369

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Presentations

  • Effect of Electrolyte Composition on the Current Efficiency for Aluminium Deposition from Molten Fluoride Electrolytes with Dissolved Alumina

    Taiki Morishige, Geir Martin Haarberg, Henrik Gudbrandsen, Egil Skybakmoen, Asbjørn Solheim

    Electrochemical Society Inc.  2016 

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    Event date: 2016

    Venue:Honolulu, HI  

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  • 高温フッ化物溶融塩中でのチタン電解における還元反応と溶質の関係

    山中 優佳, 森重 大樹, 竹中 俊英

    公益社団法人 電気化学会  2014.3 

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    Event date: 2014.3

    Venue:関西大学千里山キャンパス  

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  • LA141合金冷間圧延板における剥離腐食に及ぼす加工度の影響

    須磨 拓大, 長尾 祐樹, 森重 大樹, 竹中 俊英

    公益社団法人 日本金属学会  2014.3 

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    Event date: 2014.3

    Venue:東京工業大学大岡山キャンパス  

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  • LA141マグネシウム合金の腐食挙動に及ぼす微量Fe元素の影響

    岡野 将大, 植野 公美子, 後藤 崇之, 中村 英次, 森重 大樹, 竹中 俊英

    公益社団法人 日本金属学会  2014.3 

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    Event date: 2014.3

    Venue:東京工業大学大岡山キャンパス  

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  • 振動層を利用した金属スクラップからのマグネシウムの比重分離

    村佐 奏志郎, 岡田 信太郎, 森重 大樹, 竹中 俊英

    公益社団法人 日本金属学会  2014.3 

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    Event date: 2014.3

    Venue:東京工業大学大岡山キャンパス  

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  • Mg-Li合金冷間圧延板の剥離腐食に及ぼす加工量の影響

    森重 大樹, 須磨 拓大, 岡野 将大, 竹中 俊英

    一般社団法人 日本機械学会関西支部  2014.3 

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    Event date: 2014.3

    Venue:大阪府立大学  

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  • Exfoliation Corrosion Behavior of cold-rolled Mg-Li-Al alloy sheet

    Taiki Morishige, Takayuki Goto, Eiji Nakamura, Toshihide Takenaka

    International Conference on Processing and Manufacturing of Advanced Materials  2013.12 

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    Event date: 2013.12

    Venue:Las Vegas, NV  

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  • 溶融LiCl-KCl浴で発生する金属霧の発生条件と発生機構

    高栁 亮介, 森重 大樹, 竹中 俊英

    社団法人 電気化学会溶融塩委員会  2013.11 

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    Event date: 2013.11

    Venue:慶應義塾大学日吉キャンパス  

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  • 溶融LiCl-KCl浴におけるLi電析に及ぼすLi2O添加の影響

    秦 俊貴, 高栁 亮介, 森重 大樹, 竹中 俊英

    社団法人 電気化学会溶融塩委員会  2013.11 

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    Event date: 2013.11

    Venue:慶應義塾大学日吉キャンパス  

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  • LiCl-KCl共晶塩中におけるNiFe2O4サーメットの陽極挙動

    荒木 大地, 森重 大樹, 竹中 俊英

    社団法人 電気化学会溶融塩委員会  2013.11 

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    Event date: 2013.11

    Venue:慶應義塾大学日吉キャンパス  

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  • 溶融塩電解によるLi採取に用いるTiおよびMo陽極の検討

    柴田 浩典, 荒木 大地, 森重 大樹, 竹中 俊英

    社団法人 電気化学会溶融塩委員会  2013.11 

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    Event date: 2013.11

    Venue:慶應義塾大学日吉キャンパス  

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  • 溶融塩電解で炭素系電極の材質と陽極反応の関係性

    塩見 大樹, 森重 大樹, 竹中 俊英

    社団法人 電気化学会溶融塩委員会  2013.11 

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    Event date: 2013.11

    Venue:慶應義塾大学日吉キャンパス  

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  • Fe Elimination From Mg by Carbide Formation

    Toshihide Takenaka, Ryuunosuke Morikawa, Taiki Morishige

    MS & T  2013.10 

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    Event date: 2013.10

    Venue:Montreal, QC, Canada  

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  • 高温フッ化物溶融塩中でのTi製錬における電解浴組成と電析機構の関係

    山中 優佳, 森重 大樹, 竹中 俊英

    公益社団法人 日本金属学会  2013.9 

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    Event date: 2013.9

    Venue:金沢大学角間キャンパス  

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  • Mg-Al溶湯中へのTi浸漬による不純物Cuの拡散挙動

    下村 麻人, 森重 大樹, 竹中 俊英

    公益社団法人 日本金属学会  2013.9 

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    Event date: 2013.9

    Venue:金沢大学角間キャンパス  

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  • Diffusion of Cu to Ti in Magnesium Melt for Purification Process

    Taiki Morishige, Yuki Konishi, Asato Shimomura, Toshihide Takenaka

    TMS  2013.8 

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    Event date: 2013.8

    Venue:Hawaii, HI  

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  • 溶融LiCl-KCl浴中における金属霧の発生についての調査

    高栁 亮介, 森重 大樹, 竹中 俊英

    公益社団法人 日本金属学会  2013.3 

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    Event date: 2013.3

    Venue:東京理科大学神楽坂キャンパス  

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  • 塩水環境中でのマグネシウム‐リチウム合金冷間圧延板の剥離腐食における腐食発生機構

    森重 大樹, 土居 弘和, 後藤 崇之, 中村 英次, 竹中 俊英

    公益社団法人 日本金属学会  2013.3 

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    Event date: 2013.3

    Venue:東京理科大学神楽坂キャンパス  

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  • Effect of Microstructure on the Corrosion Behavior of Mg-Li-Al alloy

    Taiki Morishige, Hirokazu Doi, Takayuki Goto, Eiji Nakamura, Toshihide Takenaka

    Proceedings of 9th International Conference on Magnesium Alloys and their Applications  2012.7 

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    Event date: 2012.7

    Venue:Vancouver, BC, Canada  

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  • Mg-Li合金冷間圧延材の剥離腐食の進行速度に及ぼすミクロ組織の影響

    森重 大樹, 土居 弘和, 後藤 崇之, 中村 英次, 竹中 俊英

    一般社団法人日本マグネシウム協会  2012.6 

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    Event date: 2012.6

    Venue:江戸東京博物館  

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  • Mg-Li合金冷間圧延材の剥離腐食の進行速度に及ぼすミクロ組織の影響

    森重 大樹, 土居 弘和, 後藤 崇之, 中村 英次, 竹中 俊英

    一般社団法人軽金属学会  2012.5 

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    Event date: 2012.5

    Venue:九州大学伊都キャンパス  

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  • Mg-Li合金冷間圧延板の剥離腐食に及ぼす微細析出物の影響

    土居 弘和, 森重 大樹, 後藤 崇之, 中村 英次, 竹中 俊英

    社団法人日本金属学会 2012年春期(第150回)大会  2012.3 

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    Event date: 2012.3

    Venue:横浜国立大学常盤台キャンパス  

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  • グラファイトを利用したマグネシウム中の不純物Fe除去方法の検討

    小西 優輝, 森重 大樹, 竹中 俊英

    社団法人 日本金属学会 2012年春期(第150回)大会  2012.3 

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    Event date: 2012.3

    Venue:横浜国立大学常盤台キャンパス  

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  • マグネシウム中のFe, Cuの除去に関する研究

    小西 優輝, 中江 雄大, 森川 龍之介, 日竎 義裕, 森重 大樹, 竹中 俊英

    社団法人日本金属学会2011年秋期講演大会  2011.11 

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    Event date: 2011.11

    Venue:沖縄コンベンションセンターおよびカルチャーリゾートフェストーネ  

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  • Mg-Li合金における剥離腐食挙動の調査

    土居 弘和, 長谷川 祥治, 高畠 佳佑, 後藤 崇之, 中村 英次, 森重 大樹, 竹中 俊英

    社団法人日本金属学会2011年秋期講演大会  2011.11 

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    Event date: 2011.11

    Venue:沖縄コンベンションセンターおよびカルチャーリゾートフェストーネ  

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  • 難燃性マグネシウム合金とアルミニウム合金の異種金属摩擦攪拌接合

    平田 智丈, 田中 努, 森重 大樹, 北沢 孝次

    一般社団法人軽金属学会  2011.11 

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    Event date: 2011.11

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  • Explanation of anodic behaviors in LiCl-KCl melt by electrochemical response and in situ observation

    2011.9 

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    Event date: 2011.9

    Venue:Yoshida-south Campus, Kyoto University  

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  • Corrosion behavior of cold-rolled Mg-14wt.%Li-1wt.%Al alloy in NaCl solution

    2011.9 

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    Event date: 2011.9

    Venue:Yoshida-south Campus, Kyoto University  

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  • Effect of Alloying Element on the Minimum Grain Size of Al alloys using Friction Stir Processing

    Taiki Morishige, Tomotake Hirata, Masato Tsujikawa, Kenji Higashi, Toshihide Takenaka

    THERMEC' 2011  2011.8 

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    Event date: 2011.8

    Venue:Quebec city convention centre  

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  • Effect of purity level on the grain size in SPD-processed pure aluminums

    平田 智丈, 森重 大樹, 辻川 正人, 上杉 徳照, 瀧川 順庸, 東 健司

    一般社団法人軽金属学会  2011.5 

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    Event date: 2011.5

    Venue:名古屋大学  

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  • 強ひずみ加工を施したAl-Mg系合金の最小結晶粒径に及ぼすMg固溶量の影響

    森重 大樹, 平田 智丈, 辻川 正人, 上杉 徳照, 瀧川 順庸, 東 健司

    一般社団法人軽金属学会  2011.5 

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    Event date: 2011.5

    Venue:名古屋大学  

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  • Influences of alloying elements on the grain sizes in friction stir processed pure aluminum and aluminum alloys

    Tomotake Hirata, Taiki Morishige, Masato Tsujikawa, Kenji Higashi

    TMS Annual Meeting 2011  2011.2 

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    Event date: 2011.2 - 2011.3

    Venue:San Diego, California  

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  • Optimization of Anodizing Condition for Mg-14mass%Li-3mass%Al alloy

    Taiki MORISHIGE, Satoki TAKIYAMA, Yuka ICHIGI, Toshihide TAKENAKA

    THERMEC‘2023 – International Conference on Processing & Manufacturing of advanced Materials  2023.7 

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    Venue:Vienna, Austria  

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  • Effect of Distributions of Low Angle Grain Boundary and Dislocation Density on Strength of Al-3mass%Mg by SPD

    Atsushi KOZAKI, Taiki MORISHIGE, Tsutomu TANAKA

    THERMEC‘2023 – International Conference on Processing & Manufacturing of advanced Materials  2023.7 

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    Venue:Vienna, Austria  

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  • Effect of Pre-sintering in Silicothermic Reduction of MgO and Reduction Using Ca2SiO4 instead of CaO

    Takeru Saimura, Taiki Morishige, Toshihide Takenaka

    2021 

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  • Improvement of Corrosion Resistance by Zn Addition to Mg Alloy Containing Impurity Ni

    Koki Ezumi, Taiki Morishige, Tetsuo Kikuchi, Ryuichi Yoshida, Taiki Morishige

    2021 

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  • Oxide Films Formed on MoSi2 Anode in Molten MgCl2-NaCl-CaCl2 and Molten LiCl-KCl

    Takamasa Miyoshi, Taiki Morishige, Toshihide Takenaka

    2021 

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  • Effect of Microstructure on Corrosion Behavior of Cold-Rolled Mg-Li-Al alloy

    Taiki Morishige, Hayato Ikoma, Toshihide Takenaka

    2021 

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  • Effect of Cation Species in the Electrolyte on the Oxidized Film on the Anodizing of Mg-Li-Al alloys

    Yuka Ichigi, Taiki Morishige, Toshihide Takenaka

    2021 

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  • Effects of MgCl2 and NaCl on Si-Thermic Reduction of MgO in Recycle of Mg-air Battery

    Atsushi Hayashida, Toshihide Takenaka, Taiki Morishige

    2021 

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Awards

  • 奨励賞

    2018.6   一般社団法人日本マグネシウム協会  

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    Country:Japan

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  • 研究奨励賞

    2009.6   社団法人日本鋳造工学会関西支部  

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    Country:Japan

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Research Projects

  • Innovative production process of Ti and Si by electrolysis in molten CaCl2 at high temperature

    Grant number:18H01763  2018.4 - 2022.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Takenaka Toshihide

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    Grant amount:\17160000 ( Direct Cost: \13200000 、 Indirect Cost:\3960000 )

    Electrolytic production of Ti metal and Si metal in molten CaCl2 with their oxides was investigated in this study.
    TiO2 dissolved in molten CaCl2 with CaO, and Ti metal electrodeposited. The molar ratio of CaO to TiO2 strongly affected the Ti metal deposition. Ti metal was obtained only in the bath where CaO:TiO2 = 3:2., but the obtained Ti was a little even under this condition. It was suggested that the so-called shuttle reaction hindered the Ti deposition.Calcium silicate dissolved in molten CaCl2, and Si metal was obtained. The influence of the molar ratio of CaO to SiO2 on the Si deposition was seen, but Si metal electrodeposited effectively under the suitable condition.

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  • Progressive research on innert anode for Li and Mg electrolysis in molten chloride

    Grant number:26289282  2014.4 - 2017.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Takenaka Toshihide

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    Grant amount:\16250000 ( Direct Cost: \12500000 、 Indirect Cost:\3750000 )

    Innovative material of inert anode for Li and Mg electrolysis in molten chloride containing oxide ions of impurity-level was studied. The anodic dissolution of carbon/graphite was hardly prevented, and nickel ferrite was dissolved by immersion. A TiO2 layer was not formed on Mo-Ti or Mo-Ti-Ru alloy, and their dissolution was rarely inhibited. The anodic behaviors of SiC strongly depended on the existence of oxide ions in melt, and a SiO2 layer was formed on its surface by electrolysis. The formed SiO2 seemed stable even under Cl2 gas generation, and its anodic dissolution was considerably lessened. The anodic behavior of MoSi2 resembled that of SiC. These results indicate that SiC and MoSi2 are potential as inert anode material in molten chloride containing oxide ions. The formation of a homogeneous and coherent SiO2 layer with better electric conductivity should be studied to apply them as a practical inert anode.

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  • Novel Process of Practical Impurity Removal from Magnesium Scrap

    Grant number:21560770  2009 - 2011

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    TAKENAKA Toshihide, MORISHIGE Taiki

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    Grant amount:\4810000 ( Direct Cost: \3700000 、 Indirect Cost:\1110000 )

    Aiming at the development of the practical recycle process of Mg materials, the removal of Fe and Cu, which seriously deteriorate the properties of Mg materials and are easily contaminated in recycle process, has been investigated. Fe which has a stronger affinity with carbon than Mg was eliminated by simply adding a carbon source and additives in Mg melt. It was also found that Cu could be absorbed to Ti metal immersed in Mg melt.

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  • Analysis of effects of fine nanoparticles and grain boundary character distribution on abnormal grain growth in friction stir welded material

    Grant number:20760502  2008 - 2010

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    HIRATA Tomotake, TANAKA Tsutomu, MORISHIGE Taiki, HIGASHI Kenji, TSUJIKAWA Masato, TAKIGAWA Yorinobu, UESUGI Tokuteru

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    Grant amount:\3510000 ( Direct Cost: \2700000 、 Indirect Cost:\810000 )

    In the friction stir welded (FSW) material, the abnormal grain growth (AGG) often occurs in the microstructure of the weld zone during the post-FSW heat treatment. In this study, the influence of microstructural features on GG was investigated to prevent the AGG. The addition of fine nanoparticles was effective for preventing the AGG. And also it was considered to prevent GG by controlling the grain boundary character distribution by the optimization of welding condition. In addition, it was confirmed that the grain size can be controlled by adjusting the alloying element and the purity level. It is concluded that these results are very important to improve a reliability of FSWed material.

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  • 摩擦攪拌接合による異材接合

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    Grant type:Competitive

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  • 摩擦攪拌プロセスを用いた軽合金の改質

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    Grant type:Competitive

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Devising educational methods

  • 授業外での質問には常時対応。実験でのレポート指導においては、とにかく疑問に思った内容を書き並べ、積極的に考察させる。

Teaching materials

  •  特になし

Teaching method presentations

  •  特になし

Special notes on other educational activities

  • 日本私立大学連盟平成23年度FD推進ワークショップに参加