Severe plastic deformation for producing superfunctional ultrafine-grained and heterostructured materials: An interdisciplinary review
Kaveh Edalati; Anwar Q. Ahmed; Saeid Akrami; Kei Ameyama; Valery Aptukov; Rashid N. Asfandiyarov; Maki Ashida; Vasily Astanin; Andrea Bachmaier; Victor Beloshenko; Elena V. Bobruk; Krzysztof Bryła; José María Cabrera; Amanda P. Carvalho; Nguyen Q. Chinh; In Chul Choi; Robert Chulist; Jorge M. Cubero-Sesin; Gregory Davdian; Muhammet Demirtas; Sergiy Divinski; Karsten Durst; Jiri Dvorak; Parisa Edalati; Satoshi Emura; Nariman A. Enikeev; Ghader Faraji; Roberto B. Figueiredo; Ricardo Floriano; Marjan Fouladvind; Daniel Fruchart; Masayoshi Fuji; Hiroshi Fujiwara; Marcell Gajdics; Diana Gheorghe; Lukasz Gondek; Joaquín E. González-Hernández; Alena Gornakova; Thierry Grosdidier; Jenő Gubicza; Dmitry Gunderov; Liqing He; Oscar Fabian Higuera; Shoichi Hirosawa; Anton Hohenwarter; Zenji Horita; Jelena Horky; Yi Huang; Jacques Huot; Yoshifumi Ikoma; Tatsumi Ishihara; Yulia Ivanisenko; Jae il Jang; Alberto M. Jorge; Mie Kawabata-Ota; Megumi Kawasaki; Tarek Khelfa; Junya Kobayashi; Lembit Kommel; Anna Korneva; Petr Kral; Natalia Kudriashova; Shigeru Kuramoto; Terence G. Langdon; Dong Hyun Lee; Valery I. Levitas; Cong Li; Hai Wen Li; Yongtao Li; Zheng Li; Huai Jun Lin; Klaus Dieter Liss; Ying Liu; Diana Maritza Marulanda Cardona; Kenji Matsuda; Andrey Mazilkin; Yoji Mine; Hiroyuki Miyamoto; Suk Chun Moon; Timo Müller; Jairo Alberto Muñoz; Maxim Yu Murashkin; Muhammad Naeem; Marc Novelli; Dániel Olasz; Reinhard Pippan; Vladimir V. Popov; Elena N. Popova; Gencaga Purcek; Patricia de Rango; Oliver Renk; Delphine Retraint; Ádám Révész; Virginie Roche; Pablo Rodriguez-Calvillo; Liliana Romero-Resendiz; Xavier Sauvage; Takahiro Sawaguchi; Hadi Sena; Hamed Shahmir
Journal of Alloys and Compounds, 1002, 15 Oct. 2024, Book review
ECAP加工に供したMg-Y-Zn合金の組織と局所硬さの関係
星野孝男; 湯浅元仁; 湯浅元仁; 安藤大輔; 染川英俊; 宮本博之
日本金属学会講演大会(Web), 168th, 2021
塑性加工プロセスがキンク形成に及ぼす影響
湯浅元仁; 湯浅元仁; 染川英俊; 戸高義一; 安藤大輔; 宮本博之
日本金属学会講演大会(Web), 169th, 2021
Effects of Stacking Fault Energy and Solute Atoms on Microstructures of Ultrafine Grained Copper Alloys Processed by Severe Plastic Deformation
浅野 真由; 湯浅 元仁; 宮本 博之
銅と銅合金 : 銅及び銅合金技術研究会誌 = Copper and copper alloy : journal of Japan Research Institute for Advanced Copper-Base Materials and Technologies, 日本伸銅協会, 60(1) 29 - 34, 2021
Microstructure and mechanical properties of Mg-Y-Zn alloys processed by Equal-Channel-Angular-Pressing
星野孝男; 湯浅元仁; 湯浅元仁; 安藤大輔; 染川英俊; 宮本博之
軽金属学会大会講演概要, 138th, 2020
Relationship between strain distribution and hardness of Mg-Y-Zn alloy processed by severe plastic deformation
湯浅元仁; 湯浅元仁; 星野孝男; 中筋悠斗; 中筋悠斗; 安藤大輔; 染川英俊; 宮本博之
軽金属学会大会講演概要, 138th, 2020
Deformation-kink-bands and mechanical properties of Mg-Y-Zn alloys with LPSO phases processed by ECAP
星野孝男; 湯浅元仁; 湯浅元仁; 安藤大輔; 染川英俊; 宮本博之
軽金属学会大会講演概要, 139th, 2020
MgY2Zn1合金におけるECAP材の微視的構造と機械特性
星野孝男; 湯浅元仁; 湯浅元仁; 安藤大輔; 染川英俊; 宮本博之
日本金属学会講演大会(Web), 167th, 2020
Corrosion behavior of severely deformed pure and single-phase materials
Hiroyuki Miyamoto; Motohiro Yuasa; Muhammad Rifai; Hiroshi Fujiwara
Materials Transactions, 60(7) 1243 - 1255, 2019, Book review
Relationship between Stress Corrosion Cracking (SCC) and Grain Size in Ultrafine-Grained Brass
朝部 麿; 阪口 晃司; 湯浅 元仁; 宮本 博之
銅と銅合金 : 銅及び銅合金技術研究会誌 = Copper and copper alloy : journal of Japan Research Institute for Advanced Copper-Base Materials and Technologies, 日本伸銅協会, 56(1) 194 - 199, 2017
Formation Mechanism of Cracks in Low-cycle Corrosion Fatigue of Metastable Austenitic Stainless Steel
Shirasaki Ryoya; Miyamoto Hiroyuki; Fujiwara Hiroshi
同志社大学ハリス理化学研究報告 = The Harris science review of Doshisha University, Alternative:Harris Science Research Institute of Doshisha University, 57(1) 1 - 6, Apr. 2016
M324 Fracture Behavior of Belt-Shaped Phosphor Bronze under Cyclic Bending Using Roller
TOGO Kotaro; NAKASIMA Hiroshi; FUJIWARA Hiroshi; MIYAMOTO Hiroyuki
関西支部講演会講演論文集, The Japan Society of Mechanical Engineers, 2016(91) 276 - 276, 11 Mar. 2016
OS1116 Processing-Route Dependence of Low Cycle Fatigue Properties in ECAPed Ferritic Stainless Steel
TOMITA Ryuji; KANEKO Yoshihisa; VINOGRADOV Alexei; MIYAMOTO Hiroyuki; RIFAI Muhammad
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2014 "OS1116 - 1"-"OS1116-2", 19 Jul. 2014
OS1102 Strength and thermal properties of nanocrystalline Ni-WOx by electrodeposition
MIYAMOTO Hiroyuki; KATO Yushi; MIFUNE Tomoki; FUJIWAEA Hiroshi; GOTO Takuya
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2014 "OS1102 - 1"-"OS1102-3", 19 Jul. 2014
OS1216 Mechanical Properties and Fracture Mechanism of Harmonic Structure Composite with High Speed Steel and Mild Steel
TSUZUKI Yuki; FUJIWARA Hiroshi; MIYAMOTO Hiroyuki
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2013 "OS1216 - 1"-"OS1216-3", 12 Oct. 2013
OS1212 Crack initiation of metastable austenitic stainless steel cyclically deformed in aqueous solution
KAKIUCHI Takuma; MIYAMOTO Hiroyuki; FUJIWARA Hiroshi; MATUMURA Masatoshi
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2013 "OS1212 - 1"-"OS1212-3", 12 Oct. 2013
A microstructural aspect of intergranular stress corrosion cracking of semi-hard U-bend tubes of commercially pure copper in cooling systems
H. Miyamoto; D. Saburi; H. Fujiwara
ENGINEERING FAILURE ANALYSIS, PERGAMON-ELSEVIER SCIENCE LTD, 26 108 - 119, Dec. 2012
A microstructural aspect of intergranular stress corrosion cracking of semi-hard U-bend tubes of commercially pure copper in cooling systems
H. Miyamoto; D. Saburi; H. Fujiwara
Engineering Failure Analysis, PERGAMON-ELSEVIER SCIENCE LTD, 26 108 - 119, Dec. 2012
OS1308 Influence of Deformation Induced Martensite on the Corrosion Fatigue Life of SUS304 Steels in 3% NaCl solution
Yatsu Takumi; Ono Takafumi; Fujiwara Hiroshi; Miyamoto Hiroyuki; Matsumura Masatoshi
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2012 "OS1308 - 1"-"OS1308-3", 22 Sep. 2012
OS1306 Microstructures near fracture surfaces of Cu-10%Zn alloy fractured in different manners
KANEKO Yoshihisa; TOMIYAMA Ryo; MIYAMOTO Hiroyuki; HASHIMOTO Satoshi
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2012 "OS1306 - 1"-"OS1306-2", 22 Sep. 2012
312 Age Hardening Mechanism and Mechanical Properties of Nanocrystalline Ni-P Complex Metal by Electrodeposition
Kobayashi Natsu; Miyamoto Hiroyuki; Uenoya Toshiyuki; Hujiwara Hiroshi
関西支部講演会講演論文集, The Japan Society of Mechanical Engineers, 2012(87) "3 - 17", 16 Mar. 2012
311 Synthesis and mechanical properties of nanocrystalline Ni-WO_3 by electrodeposition
Takehara Shota; Miyamoto Hiroyuki; Uenoya Toshiyuki; Hujiwara Hiroshi
関西支部講演会講演論文集, The Japan Society of Mechanical Engineers, 2012(87) "3 - 16", 16 Mar. 2012
420 Identification of Damage Mechanism and CharacteriZation of Damage Developmentin Fatigue of Thermoplastic Composites through Thermoelastic Analysis
UENOYA Toshiyuk; KAWAMATA Saori; SUZUKI Ryuta; MIYAMOTO Hiroyuki
関西支部講演会講演論文集, The Japan Society of Mechanical Engineers, 2011(86) "4 - 20", 19 Mar. 2011
Reversible nature of shear bands in copper single crystals subjected to iterative shear of ECAP in forward and reverse directions
Hiroyuki Miyamoto; Takumi Ikeda; Toshiyuki Uenoya; Alexei Vinogradov; Satoshi Hashimoto
Materials Science and Engineering A, ELSEVIER SCIENCE SA, 528(6) 2602 - 2609, 15 Mar. 2011
Reversible nature of shear bands in copper single crystals subjected to iterative shear of ECAP in forward and reverse directions
Hiroyuki Miyamoto; Takumi Ikeda; Toshiyuki Uenoya; Alexei Vinogradov; Satoshi Hashimoto
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 528(6) 2602 - 2609, Mar. 2011
331 Making of oxide dispersion nano crystal Ni by electrodeposition
竹原 翔太; 宮本 博之; 後藤 琢也
学術講演会講演論文集, 日本材料学会, 60 219 - 220, 2011
Enhanced corrosion fatigue resistance of AISI304 bellows expansion by modifying the bellows shape
Takafumi Ono; Tomomi Fujikawa; Hiroyuki Miyamoto; Toshiyuki Uenoya; Masatoshi Matsumura
Materials Science and Technology Conference and Exhibition 2011, MS and T'11, 2 1261 - 1268, 2011
Enhanced corrosion fatigue resistance of AISI304 bellows expansion by modifying the bellows shape
Takafumi Ono; Tomomi Fujikawa; Hiroyuki Miyamoto; Toshiyuki Uenoya; Masatoshi Matsumura
AIST Steel Properties and Applications Conference Proceedings - Combined with MS and T'11, Materials Science and Technology 2011, 611 - 618, 2011
720 Characterization of fatigue damage development in stitched CF/NY6 orthotropic laminates
UENOYA Toshiyuki; SUZUKI Ryuta; MIYAMOTO Hiroyuki
M&M材料力学カンファレンス, The Japan Society of Mechanical Engineers, 2010 458 - 460, 09 Oct. 2010
507 Prediction and Extension of Fatigue Life of a New Type Bel lows
MAEDA Yasuharu; MIYAMOTO Hiroyuki; UENOYA Toshiyuki; MATSUMURA Masatoshi
関西支部講演会講演論文集, The Japan Society of Mechanical Engineers, 2010(85) "5 - 7", 16 Mar. 2010
Mechanical properties of Ni-Al2O3 nanocomposites by electrodeposition
上田 孝史郎; 宮本 博之; 上野谷 敏之
The Science and engineering review of Doshisha University, 同志社大学理工学研究所, 50(4) 151 - 156, Jan. 2010
Formation of Deformation Twins and Related Shear Bands in Copper Single Crystals Pressed by ECAP
Takumi Ikeda; Hiroyuki Miyamoto; Toshiyuki Uenoya; Satoshi Hashimoto; Alexei Vinogradov
PRICM 7, PTS 1-3, TRANS TECH PUBLICATIONS LTD, 654-656 1231 - +, 2010
Mechanical Properties of Electrodeposited Ni-SiO2 Nanocomposite
Hiroyuki Miyamoto; Koushirou Ueda; Toshiyuki Uenoya
PRICM 7, PTS 1-3, TRANS TECH PUBLICATIONS LTD, 654-656 1162 - 1165, 2010
Effect of Simple Shear Deformation Prior to Cold Rolling on Texture and Ridging of 16% Cr Ferritic Stainless Steel Sheets
Hiroyuki Miyamoto; Tong Xiao; Toshiyuki Uenoya; Masaharu Hatano
ISIJ INTERNATIONAL, IRON STEEL INST JAPAN KEIDANREN KAIKAN, 50(11) 1653 - 1659, 2010
Formation of deformation twins and related shear bands in copper single crystals pressed by ECAP
Takumi Ikeda; Hiroyuki Miyamoto; Toshiyuki Uenoya; Satoshi Hashimoto; Alexei Vinogradov
Materials Science Forum, TRANS TECH PUBLICATIONS LTD, 654-656 1231 - 1234, 2010
Mechanical properties of electrodeposited Ni-SiO
2 nanocomposite
Hiroyuki Miyamoto; Koushirou Ueda; Toshiyuki Uenoya
Materials Science Forum, TRANS TECH PUBLICATIONS LTD, 654-656 1162 - 1165, 2010
Effect of simple shear deformation prior to cold rolling on texture and ridging of 16% Cr ferritic stainless steel sheets
Hiroyuki Miyamoto; Tong Xiao; Toshiyuki Uenoya; Masaharu Hatano
ISIJ International, IRON STEEL INST JAPAN KEIDANREN KAIKAN, 50(11) 1653 - 1659, 2010
Formation of deformation twins and related shear bands in a copper single crystal deformed by equal-channel angular pressing for one pass at room temperature
Hiroyuki Miyamoto; Alexei Vinogradov; Satoshi Hashimoto; Rika Yoda
Materials Transactions, JAPAN INST METALS, 50(8) 1924 - 1929, Aug. 2009
Formation of Deformation Twins and Related Shear Bands in a Copper Single Crystal Deformed by Equal-Channel Angular Pressing for One Pass at Room Temperature
Hiroyuki Miyamoto; Alexel Vinogradov; Satoshi Hashimoto; Rika Yoda
MATERIALS TRANSACTIONS, JAPAN INST METALS, 50(8) 1924 - 1929, Aug. 2009
411 The influence of strain path on the development of shear bands in copper single crystal pressed by ECAP
IKEDA Takumi; KATAYAMA Soichi; MIYAMOTO Hiroyuki; UENOYA Toshiyuki; HASHIMOTO Satoshi; Vinogradov Alexei
学術講演会講演論文集, 日本材料学会, 58 285 - 286, 2009
410 Mechanical Properties of electrodeposited Ni and NiAl_2O_3
UEDA Koushirou; MIYAMOTO Hiroyuki; UENOYA Toshiyuki
学術講演会講演論文集, 日本材料学会, 58 283 - 284, 2009
Corrosion of ultra-fine grained copper fabricated by equal-channel angular pressing
Hiroyuki Miyamoto; Kohei Harada; Takuro Mimaki; Alexei Vinogradov; Satoshi Hashimoto
CORROSION SCIENCE, PERGAMON-ELSEVIER SCIENCE LTD, 50(5) 1215 - 1220, May 2008
Corrosion of ultra-fine grained copper fabricated by equal-channel angular pressing
Hiroyuki Miyamoto; Kohei Harada; Takuro Mimaki; Alexei Vinogradov; Satoshi Hashimoto
Corrosion Science, PERGAMON-ELSEVIER SCIENCE LTD, 50(5) 1215 - 1220, May 2008
Application of ECAP for ferritic stainless steel sheets to enhance formability
宮本 博之; 御牧 拓郎; 松永 雅宏
The Science and engineering review of Doshisha University, 同志社大学理工学研究所, 48(4) 119 - 125, Jan. 2008
Influence of a slip plane orientation with respect to the shear plane of ECAP on microstructure of copper single crystal subject to one pressing at room temperature
Soichi Katayama; Hiroyuki Miyamoto; Alexei Vinogradov; Satoshi Hashimoto
NANOMATERIALS BY SEVERE PLASTIC DEFORMATION IV, PTS 1 AND 2, TRANS TECH PUBLICATIONS LTD, 584-586 387 - 392, 2008
Influence of a slip plane orientation with respect to the shear plane of ECAP on microstructure of copper single crystal subject to one pressing at room temperature
Soichi Katayama; Hiroyuki Miyamoto; Alexei Vinogradov; Satoshi Hashimoto
Materials Science Forum, TRANS TECH PUBLICATIONS LTD, 584-586 PART 1 387 - 392, 2008
235 Fatigue life prediction of Bellows type expansion joint by FEM and effect of shape parameters
Iguchi Ryo; Miyamoto Hiroyuki; Mimaki Takuro; Uchida Hiroshi
Materials and processing conference, The Japan Society of Mechanical Engineers, 2007(15) 163 - 164, 16 Nov. 2007
Mechanism of corrosion and tarnishing in pure copper
宮本 博之
Material stage, 技術情報協会, 7(6) 1 - 4, Sep. 2007
Sensitivity to fatigue cracks initiation of symmetrical < 110 > tilt grain boundaries in pure copper bicrystals in 1M NaNO2 solution
H. Miyamoto; K. Kuroda; T. Mimaki
PRICM 6: SIXTH PACIFIC RIM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS AND PROCESSING, PTS 1-3, TRANS TECH PUBLICATIONS LTD, 561-565 2415 - 2418, 2007
Sensitivity to fatigue cracks initiation of symmetrical 〈110〉tilt grain boundaries in pure copper bicrystals in 1M NaNO
2 solution
H. Miyamoto; K. Kuroda; T. Mimaki
Materials Science Forum, 561-565(PART 3) 2415 - 2418, 2007
Viscous nature of deformation of ultra-fine grain aluminum processed by equal-channel angular pressing
H Miyamoto; K Ota; T Mimaki
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 54(10) 1721 - 1725, May 2006
Viscous nature of deformation of ultra-fine grain aluminum processed by equal-channel angular pressing
H. Miyamoto; K. Ota; T. Mimaki
Scripta Materialia, PERGAMON-ELSEVIER SCIENCE LTD, 54(10) 1721 - 1725, May 2006
429 Texture development and deformation twinning of copper single crystal Due to ECAP
KINOSHITA Masato; MIYAMOTO Hiroyuki; MIMAKI Takuro; HASHIMOTO Satoshi; VINOGRADOV Alexei
学術講演会講演論文集, 日本材料学会, 55 331 - 332, 2006
430 Deformation mechanism of ultra-fine grain Al processed by ECAP
MIYAMOTO Hiroyuki; Ota Kensaku; MIMAKI Takuro
学術講演会講演論文集, 日本材料学会, 55 333 - 334, 2006
The effect of the initial orientation on microstructure development of copper single crystals subjected to equal-channel angular pressing
H Miyamoto; J Fushimi; T Mimaki; A Vinogradov; S Hashimoto
NANOMATERIALS BY SEVERE PLASTIC DEFORMATION, TRANS TECH PUBLICATIONS LTD, 503-504 799 - 804, 2006
The effect of the initial orientation on microstructure development of copper single crystals subjected to equal-channel angular pressing
H. Miyamoto; J. Fushimi; T. Mimaki; A. Vinogradov; S. Hashimoto
Materials Science Forum, TRANS TECH PUBLICATIONS LTD, 503-504 799 - 804, 2006
Dislocation structures and crystal orientations of copper single crystals deformed by equal-channel angular pressing
H. Miyamoto; J. Fushimi; T. Mimaki; A. Vinogradov; S. Hashimoto
Materials Science and Engineering A, ELSEVIER SCIENCE SA, 405(1-2) 221 - 232, 25 Sep. 2005
Dislocation structures and crystal orientations of copper single crystals defonned by equal-channel angular pressing
H Miyamoto; J Fushimi; T Mimaki; A Vinogradov; S Hashimoto
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 405(1-2) 221 - 232, Sep. 2005
Interphase sliding in CuZnSn new suprplastic alloys
宮本 博之
26 119 - 125, 2005
Interphase sliding in CuZnSn new suprplastic alloys
Archives of Materials Science, 26 119 - 125, 2005
The role of grain boundary plane orientation on intergranular corrosion of symmetric and asymmetric [110] tilt grain boundaries in directionally solidified pure copper
H Miyamoto; K Ikeuchi; T Mimaki
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 50(12) 1417 - 1421, Jun. 2004
The role of grain boundary plane orientation on intergranular corrosion of symmetric and asymmetric [1 1 0] tilt grain boundaries in directionally solidified pure copper
H. Miyamoto; K. Ikeuchi; T. Mimaki
Scripta Materialia, PERGAMON-ELSEVIER SCIENCE LTD, 50(12) 1417 - 1421, Jun. 2004
Microstructure and texture development of copper single crystals deformed by equal-channel angular pressing
H Miyamoto; U Erb; T Koyama; T Mimaki; A Vinogradov; S Hashimoto
PHILOSOPHICAL MAGAZINE LETTERS, TAYLOR & FRANCIS LTD, 84(4) 235 - 243, Apr. 2004
Microstructure and texture development of copper single crystals deformed by equal-channel angular pressing
H. Miyamoto; U. Erb; T. Koyama; T. Mimaki; A. Vinogradov; S. Hashimoto
Philosophical Magazine Letters, TAYLOR & FRANCIS LTD, 84(4) 235 - 243, Apr. 2004
832 ECAP加工した超微細結晶銅の応力腐食割れ : 亀裂伝播速度に及ぼす短時間焼鈍の影響(塑性変形・変形挙動-II,一般セッション,第53期学術講演会)
宮本 博之; 加藤 千昌; 御牧 拓郎; Vinogradov A.; 橋本 敏
学術講演会講演論文集, 日本材料学会, 53 537 - 538, 2004
Relation between Unusual Morphology of Intergranular Corrosion and External Potential in a Pure Copper Bicrystal
Wakayama Naoki; Miyamoto Hiroyuki; Mimaki Takuro
The science and engineering review of Doshisha University, Doshisha University, 45(2) 28 - 33, 2004
高純度銅双結晶の対称傾角粒界における腐食反応とその特異形態
宮本 博之
銅と銅合金, 43 227 - 231, 2004
Interphase boundary sliding of two-phase (a/b),(b/g) and (g/a)CuZnSn alloy couples produced by solid-to-solid diffusion bonding
宮本 博之
380 34 - 40, 2004
Interphase boundary sliding of two-phase (a/b),(b/g) and (g/a)CuZnSn alloy couples produced by solid-to-solid diffusion bonding
Materials Science and Engineering A, 380 34 - 40, 2004
Deformation structure and crystal orientation of copper single crystals deformed by equal channel angular pressing
Hiroyuki Miyamoto; Uwe Erb; Tetsuo Koyama; Takuro Mimaki; Alexei Vinogradov; Satoshi Hashimoto
Materials Science Forum, 426-432(4) 2795 - 2800, 2003
Deformation structure and crystal orientation of copper single crystals deformed by equal channel angular pressing
H Miyamoto; U Erb; T Koyama; T Mimaki; A Vinogradov; S Hashimoto
THERMEC'2003, PTS 1-5, TRANS TECH PUBLICATIONS LTD, 426-4 2795 - 2800, 2003
Fatigue crack nucleation of pure copper single crystals in 1M NaNO
2aqueous solution
H. Miyamoto; T. Mimaki; S. Hashimoto
Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties, TAYLOR & FRANCIS LTD, 82(17-18) 3311 - 3319, Nov. 2002
Stress corrosion crack propagation behaviour of ultra-fine grained copper produced by equal-channel angular pressing technique
Takashi Yamasaki; Hiroyuki Miyamoto; Takuro Mimaki
Zairyo/Journal of the Society of Materials Science, Japan, 51(11) 1248 - 1252, Nov. 2002
Fatigue crack nucleation of pure copper single crystals in 1 M NaNO2 aqueous solution
H Miyamoto; T Mimaki; S Hashimoto
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, TAYLOR & FRANCIS LTD, 82(17-18) 3311 - 3319, Nov. 2002
Behavior of intergranular corrosion of <011> tilt grain boundaries of pure copper bicrystals
H. Miyamoto; K. Yoshimura; T. Mimaki; M. Yamashita
Corrosion Science, PERGAMON-ELSEVIER SCIENCE LTD, 44(8) 1835 - 1846, Aug. 2002
Corrosion, stress corrosion cracking and fatigue of ultra-fine grain copper fabricated by severe plastic deformation
A Vinogradov; H Miyamoto; T Mimaki; S Hashimoto
ANNALES DE CHIMIE-SCIENCE DES MATERIAUX, EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER, 27(3) 65 - 75, May 2002
115 <011> 傾角粒界双結晶の粒界腐食尾根形成について
谷口 旭; 宮本 博之; 山下 正人; 御牧 拓郎
学術講演会講演論文集, 日本材料学会, 51 29 - 30, 2002
113 単一および二重すべり系を有する Cu-9at.%Al 合金単結晶の腐食疲れについて
金 鳳蓮; 宮本 博之; 橋本 敏; 御牧 拓郎
学術講演会講演論文集, 日本材料学会, 51 25 - 26, 2002
Mechanical, Thermal and Stress-Corrosion Properties of Ultra-Fine Grain Copper
宮本 博之
27 197 - 206, 2002
等径角度付き押し出し法により作製された超微細結晶銅の応力腐食き裂伝ぱ挙動
宮本 博之
材料, (51) 1248 , 2002
Mechanical, Thermal and Stress-Corrosion Properties of Ultra-Fine Grain Copper
宮本 博之
Ann Chim Sci Mat, (27) S197-S206 , 2002
Corrosion, stress corrosion cracking and fatigue of ultra-fine grain copper fabricated by severe plastic deformation
Alexei Vinogradov; Hiroyuki Miyamoto; Takuro Mimaki; Satoshi Hashimoto
Annales de Chimie: Science des Materiaux, EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER, 27(3) 65 - 75, 2002
Mechanical, Thermal and Stress-Corrosion Properties of Ultra-Fine Grain Copper
Ann.Chim.Sci.Mat, 27 197 - 206, 2002
Mechanical, Thermal and Stress-Corrosion Properties of Ultra-Fine Grain Copper
Ann Chim Sci Mat, (27) S197-S206 , 2002
Behaviour of Intergranular Corrosion of <011> Tilt Grain Boundaries of Pure Copper Bicrystals
Corrosion Science, (44) 1835 - 1846, 2002
Intergranular Stress Corrosion Cracking of Pure Copper <111> Tilt Bicrystals
Interface Science, (9) 281 - 286, 2002
Cyclic deformation of ferritic stainless steel single crystals showing the stress asymmetry
Y Kaneko; Y Nagai; H Miyamoto; T Mimaki; S Hashimoto
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 319(319-321) 559 - 563, Dec. 2001
Tensile orientation dependence of surface-roughness evolution in cyclically deformed Fe-30%Cr alloy single crystals
Takashi Yamasaki; Yoshihisa Kaneko; Hiroyuki Miyamoto; Satoshi Hashimoto; Takuro Mimaki
Materials Science and Engineering A, ELSEVIER SCIENCE SA, 319-321(319-321) 569 - 573, Dec. 2001
Superplastic deformation of micro-specimens of duplex stainless steel
H Miyamoto; T Mimaki; S Hashimoto
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 319(319-321) 779 - 783, Dec. 2001
Cylic deformation of ferritic stainless steel single crystals showing the stress asymmetry
Y. Kaneko; Y. Nagai; H. Miyamoto; T. Mimaki; S. Hashimoto
Materials Science and Engineering A, ELSEVIER SCIENCE SA, 319-321(319-321) 559 - 563, Dec. 2001
Tensile orientation dependence of surface-roughness evolution in cyclically deformed Fe-30%Cr alloy single crystals
T Yamasaki; Y Kaneko; H Miyamoto; S Hashimoto; T Mimaki
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 319(319-321) 569 - 573, Dec. 2001
Superplastic deformation of micro-specimens of duplex stainless steel
Hiroyuki Miyamoto; Takuro Mimaki; Satoshi Hashimoto
Materials Science and Engineering A, ELSEVIER SCIENCE SA, 319-321(319-321) 779 - 783, Dec. 2001
Intergranular stress corrosion cracking of pure copper 〈111〉 tilt bicrystals
Hiroyuki Miyamoto; Hirohito Koga; Takuro Mimaki; Satoshi Hashimoto
Interface Science, 9(3-4) 281 - 286, Nov. 2001
Stress corrosion cracking susceptibility of ultra-fine grain copper produced by equal-channel angular pressing
T. Yamasaki; H. Miyamoto; T. Mimaki; A. Vinogradov; S. Hashimoto
Materials Science and Engineering A, ELSEVIER SCIENCE SA, 318(1-2) 122 - 128, Nov. 2001
Stress corrosion cracking susceptibility of ultra-fine grain copper produced by equal-channel angular pressing
T Yamasaki; H Miyamoto; T Mimaki; A Vinogradov; S Hashimoto
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 318(1-2) 122 - 128, Nov. 2001
Effect of Strain Rate on the Corrosion Fatigue Crack Propagation of Cu-9at%Al Single Crystals
宮本 博之
Procceeding of ESCCD2, 2001
等径角度付き押出し法により作製された超微細結晶銅の1kmol/m3 NaNO2水溶液中での繰り返し変形
宮本 博之
日本金属学会誌, (65) 843 - 847, 2001
Phase Transformation in Solid-Solid Diffusion Bonding
Miyamoto Hiroyuki; Mimaki Takuro; Hashimoto Satoshi
The science and engineering review of Doshisha University, Doshisha University, 42(42) 54 - 61, 2001
Effect of Strain Rate on the Corrosion Fatigue Crack Propagation of Cu-9at%Al Single Crystals
Procceeding of ESCCD2, 2001
Cyclic deformation in 1 Kmol/m
3 NaNO
2 aqueous solution of ultra-fine grained copper produced by equal channel-angular pressing technique
T. Yamasaki; H. Miyamoto; T. Mimaki
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, JAPAN INST METALS, 65(9) 843 - 847, 2001
Phase Transformation in Solid-Solid Diffusion Bonding
Miyamoto Hiroyuki; Mimaki Takuro; Hashimoto Satoshi
The Science and Engineering Review of Doshisha University, Doshisha University, 42(42) 54 - 61, 2001
Crack initiation behaviour in corrosion fatigue of copper single crystals in 1M NaNO
2 solution
Hiroyuki Miyamoto; Takayuki Morikawa; Takuro Mimaki; Satoshi Hashimoto
Zairyo/Journal of the Society of Materials Science, Japan, Society of Materials Science Japan, 49(11) 1179 - 1184, Nov. 2000
608 高純度銅 [011] 傾角双結晶の粒界腐食挙動
吉村 和真; 宮本 博之; 山下 正人; 御牧 拓郎
学術講演会講演論文集, 日本材料学会, 49 165 - 166, 2000
二相合金の超塑性変形における異相界面の役割
宮本 博之
同志社大学工学会報, (42) 20 , 2000
銅単結晶の1M NaNO2溶液中の腐食疲労亀裂発生挙動
宮本 博之
材料, (49) 1179 - 1184, 2000
Effect of Surface Orientatin on the Behaviour of Intergranulr Corrosion of <110> Tilt Σ 9 Grain Boundaries of High Purity Copper Bicrystals
MIYAMOTO Hiroyuki; YAHASHI Junki; YAMASHITA Masato; MIMA Takuro
The science and engineering review of Doshisha University, Doshisha University, 40(3) 121 - 129, Oct. 1999
331 高純度銅 [110] 傾角Σ9 双結晶の粒界腐食挙動
宮本 博之; 山下 正人; 矢橋 淳規; 長野 博夫; 御牧 拓郎
学術講演会講演論文集, 日本材料学会, 48 293 - 294, 1999
高純度銅Σ9<110>傾角双結晶の粒界腐食挙動に及ぼす表面方位の影響
宮本 博之
同志社大学理工学研究報告, (40) 43474 , 1999
Propagation behaviour of intergranular stress-corrosion cracking of Cu-9at.%Al bicrystals shaped to the tapered double cantilever beam specimen
T. Mimaki; H. Ando; H. Miyamoto; Y. Kaneko; S. Hashimoto
Materials Science Forum, TRANSTEC PUBLICATIONS LTD, 294-296 169 - 172, 1999
Measurement of grain boundary corrosion current on copper [110]-tilt bicrystals by scanning vibrating electrode technique
M. Yamashita; H. Miyamoto; J. Yahashi; H. Uchida; S. Hashimoto; T. Mimaki
Materials Science Forum, TRANSTEC PUBLICATIONS LTD, 294-296 739 - 742, 1999
Sliding mechanism of FCC/BCC interphase boundaries
H. Miyamoto; T. Mimaki; S. Hashimoto
Materials Science Forum, 294-296 637 - 640, 1999
Cyclic stress-strain response of ferritic stainless steel single crystals oriented for single slip and multiple slip
T Yamasaki; Y Kaneko; H Miyamoto; T Mimaki; S Hashimoto
FATIGUE '99: PROCEEDINGS OF THE SEVENTH INTERNATIONAL FATIGUE CONGRESS, VOLS 1-4, CHINA HIGHER EDUCATION PRESS BEIJING, 181-186 181 - 186, 1999
Effect of Surface Orientation on the Behaviour of Intergranular Corrosion of <110> Tilt S9 Grain boundaries of High Purity Copper Bicrystals
The Science and Engineering Review of Doshisha University, (40) 43474 , 1999
240 走査型振動電極法による Cu<110> 傾角Σ3,Σ11 双結晶の粒界腐食電位の測定
矢橋 淳規; 宮本 博之; 山下 正人; 内田 仁; 長野 博夫; 御牧 拓郎
学術講演会講演論文集, 日本材料学会, 47 257 - 258, 1998
二相ステンレス鋼双結晶の相界面すべりの機構
宮本 博之
日本金属学会誌, (62) 255 - 260, 1998
Propagation Behavior of Intergranular Stress Corrosion Cracking of Cu-9at%Al Bicrystals Shaped to the Tapered Double Cantilever Beam Specimens
Materials Science Forum, 294-296, 1998
Measurement of Grain Boundary Corrosion Current on Copper [110] Tilt Bicrystals by Scanning Vibrating Electrode Technique
Materials Science Forum, 294-296, 1998
Sliding Mechanism of BCC/FCC Interphase Boundaries
Materials Science Forum, 294-296, 1998
Mechanism of the interphase-boundary sliding in two-phase (γ/α) stainless steel bicrystals
Satoshi Hashimoto; Hiroyuki Miyamoto; Takuro Mimaki
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, JAPAN INST METALS, 62(3) 255 - 260, 1998
Role of Interphase-boundary Sliding in a Super-plastic flow of Duplex Materials Cousisting of a Soft and a Hard Phases
宮本 博之
Proceedings of JIMIS-7on Aspects of High Temperatuve Deformation and Fracture in Crystalline Material, 115 , 1993
Role of Interphase-boundary Sliding in a Super-plastic flow of Duplex Materials Cousisting of a Soft and a Hard Phases
Proceedings of JIMIS-7on Aspects of High Temperatuve Deformation and Fracture in Crystalline Material, 115 , 1993
Interphase Boundary Sliding in Two-Phase(2/2)-FeCrNi Alloy Bicrystals Produced by a Solid-Solid Diffusion Method
宮本 博之
Mechanical Behavior of Materials-VI, 6 655 , 1991
Interphase Boundary Sliding in Two-Phase(2/2)-FeCrNi Alloy Bicrystals Produced by a Solid-Solid Diffusion Method
Mechanical Behavior of Materials-VI, 6 655 , 1991
Change in the Relation between Current and Strain during Cyclic Deformation of Cu Single Crystals in a NaNO2 Solution
宮本 博之
Proceeding of Fatigue 99
Change in the Relation between Current and Strain during Cyclic Deformation of Cu Single Crystals in a NaNO2 Solution
Proceeding of Fatigue 99
強ひずみ加工法により作製した超微細結晶組織材料の逐次加工性向上
田中 達也; 宮本 博之
日本学術振興会, 科学研究費助成事業, 2022/04 -2025/03, 基盤研究(C), 同志社大学
Effect of grain refinement on corrosion behaivor of high-entropy alloys
宮本 博之
二元Fe-Cr合金やステンレス鋼では結晶粒微細化により耐食性が向上することが知られており、特に強ひずみ加工(SPD)法による結晶粒超微細化はその効果が大きい。微細化によりCrの拡散が促進されて安定な不動態皮膜を形成するためと考えられている。Cr含有ハイエントロピー合金(HEA)においても不働態被膜の形成にはCrの影響が大きく、Fe-Cr合金と同様に、結晶粒微細化による耐食性の向上が予想される.公募研究の第1期ではCr量を変化さたCoCrFeNiMn 合金を作製し,高圧ねじり加工(HPT)により結晶粒を微細化させた後に腐食挙動を調査した結果、結晶粒微細化の腐食挙動への影響は確認できなかった.一方、アーク溶解ではHEA合金特有の濃度偏析や介在物を完全除去することは難しく、微量な存在が耐食性に及ぼす影響が大きく、これらの影響も否定できない。そこで本研究ではさらに清浄度が高い真空溶解により材料を作製し、前回と同様にCr含有量を0~20at%の範囲で系統的に変化させた材料についてHPTによる結晶粒微細化が耐食性に及ぼす影響を明らかにすることを目的とした。その結果、以下のことが明らかになった。
1.Cr含有量が10%以上では粗粒材,HPT材ともに不働態化による電流抑制と孔食発生による電流上昇が確認された。Cr含有量が増加するほど孔食電位は向上した.また,粗粒材,HPT材で孔食電位に大きな差異は認められなかった.
2.0%Cr材では粗粒材およびHPT材とも不働態化が生じない。一方、6%材ではCG材では全面溶解するのに対して、HPT材で不働態化による電流抑制と孔食発生が確認された。Fe-Cr合金と同様に、結晶粒超微細化により不働態化するCr下限値以下においても不働態化が生じたものと考えられる。, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, 2021/04 -2023/03, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Doshisha University
Enhanced corrosion resistance of high entropy alloys by grain refinement
宮本 博之
本研究では,合金構成元素の割合と強ひずみ加工のひとつである高圧ねじり(HPT)加工により結晶粒を微細化させたCoCrFeNiMnハイエントロピー合金(HEA)の耐食性を調査することで,HEAの耐食性に及ぼす合金構成元素や結晶粒径の影響を調査した。材料はCrの含有量を変化させた5種類のHEAをアーク溶解にて作製し、強ひずみ加工の一種であるHPT加工を施し結晶粒を微細化させた。粗粒材(CG材)の結晶粒径は約360ミクロンであり、結晶粒微細化させたHPT材の結晶粒径は約40ナノメートルであった。耐食性の評価には1M H2SO4溶液および3.5%NaCl溶液中での分極曲線測定を用いた。結果はCr含有量が多い試料ほど孔食電位が向上し、不動態保持電流が低下し、HEAの耐食性にCrが大きな影響を与えることがわかった。また、CG材とHPT材で耐食性に大きな差は見られなかった。さらに同一のCr含有量を有する二元Fe-Cr合金とHEAを比較するとFe-Cr合金に比べHEAは耐食性が良いことがわかり、安定した不動態皮膜を形成していると考えられる.この原因を探るためXPS分析により不動態皮膜の分析を行った.表面分析からHEAの不動態皮膜は最表面ではCrの濃度が高く,不動態皮膜内部ではNiが濃化した皮膜組成になっていることがわかり、不動態皮膜内部でのNi濃化と最表面でのCr濃化の効果が合わさりがHEAの安定した不動態皮膜が形成され耐食性が向上したと考えられる.さらにHPT材とCG材では不動態被膜中でのCrおよびNi濃度の差は見られなかった。, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), 2019/04 -2021/03, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Doshisha University
Grain boundary enhanced ductility of ultrafine grained materials
Miyamoto Hiroyuki
Severe plastic deformation (SPD) can fabricate high-strength materials by forming ultrafine grained (UFG) microstructure. But, in general, as in other methods, strengthening accompanies ductility loss. Low ductility, which is usually evaluated by the uniaxial tensile tests, has been attributed to low strain hardening of UFG structure where dislocation slip and its accumulation is very limited. In the present work, it is shown that the compressive ductility, or classically called malleability of UFG materials can be comparable or potentially superior to that of coarse-grained counterparts in an appropriate stress state. The high malleability of UFG materials by SPD can be attributed to the unique deformation mechanism related with non-equilibrium grain boundaries and their high damage tolerance. The present results present a prospect for expanding industrial application of UFG materials, which has been limited because of low tensile ductility., Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, 2018/04 -2021/03, Grant-in-Aid for Scientific Research (C), Doshisha University
Corrosion properties of magnesium alloys with various microstructure by severe plastic deformation
YUASA Motohiro; MIYAMOTO Hiroyki; FURUKAWA Ryo; MAJIMA Masasige; MAULIDI Muhammad Lutfi; SARR Mouhamadou Moustapha
Corrosion resistance of ZK60 alloy and pure Mg processed by equal channel angular pressing (ECAP) was investigated using immersion tests in 5 wt% NaCl aqueous solution. The corrosion rates of ECAPed ZK60 alloys increased by increasing number of ECAP passes. Potentiodynamic polarization curves suggested that cathodic reaction was activated, and a passive film formed during immersion tests was weakened by increasing ECAP passes. This can be due to increasing intermetallic compounds and dislocation density during ECAP process. After heat treatment at 623 K for 1.5 h, the corrosion rates were significantly reduced by the heat treatment.
In contrast, the corrosion rate of pure Mg decreased after 1 pass ECAP and gradually increased after 2 pass ECAP. The grain size of ECAPed pure Mg was smaller than that of no-ECAPed pure Mg. Increasing the pass number, the grain size increased. After heat treatment, the corrosion rates increased. This can be due to the grain growth by heat treatment., Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), 2017/04 -2019/03, Grant-in-Aid for Young Scientists (B), Doshisha University
Processing of ultrafine grained materials free of residual dislocations by SPD and annealling
Miyamoto Hiroyuki
In this work, the effect of grain size in the sub-micron range on the SCC of Cu-10wt%Zn alloys is investigated using constant load tests in ammonia vapor. The grain size is systematically controlled from 0.12 μm to 40 μm by either cold-rolling or ECAP, followed by annealing. The specimens are kept in tension until fracture under a constant stress ammonia vapor.
The time to fracture has increased with decreasing grain size reaching 1 μm, but decrease with further decreasing grain size into the sub-micron range. In other words, there is a critical grain size that the susceptibility to SCC changes. Sensitivity to IGSCC is associated with GB energy. Non-equilibrium GB have higher GB energy than equilibrium GB because they contain extrinsic dislocation in grains induced by severe plastic deformation (SPD) process, and possibly exhibit GB sliding. This inverse trend in the sub-micron range is discussed in terms of a SPD-induced ultrafine grain (UFG) microstructure, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), 2014/04 -2017/03, Grant-in-Aid for Scientific Research (C), Doshisha University
電着法によるナノ粒子分散バルクナノメタルの開発と分散制御
宮本 博之
本研究の目的は、電着法を応用して母相粒径よりもさらに微細で、酸化物粒子を均一分散させたバルクナノメタルを作製し、強度や変形挙動に及ぼす影響、さらには熱的安定性向上への効果を明らかにすることを目的とする。公募第1期はナノスケールWO3粒子を懸濁させた電解液を使用した電着法によりナノ結晶Niの作製をおこなった。第2期は加水分解によるナノスケール粒子の合成と電着を組み合わせた新しい手法による粒子分散を試みている。
公募班第1期では、電解液にWO3粒子を懸濁させた電析共析法により、粒径が約40nmの母相ナノ結晶ニッケル中に10nm程度のWO3粒子が分散したナノ粒子分散ナノ結晶ニッケルを合成することに成功した。電解ニッケル中に取り込まれる過程で破砕してさらに結晶構造が単斜晶から正方晶へ変化する興味深い現象が確認された。しかし、分散粒子の凝集や偏在も一部に観察され、強度や熱的安定性への効果も限定的であった。 そこで、本年度は新しい方法として、電解液にNa2WO4と溶解させて、WO42-として電離したイオンをpHや電極電位を制御して下記の反応によりWO3粒子を電解ニッケル中に析出させて微細なWO3粒子が分散したナノ結晶Niを作製することに成功した。Na2WO4の加水分解反応によりWO3が形成した点を確認するために、本年度は予備試験として、電解開始前に一定時間放置したのちに水分を蒸発させて、残渣を回収して、X線回折、電子顕微鏡による観察を行った。その結果、WO3粒子が合成することを確認した。しかも、これらの粒子は凝集されずに分散していた。さらに電着材の組織を確認した結果、結晶粒径が約20nmの母相ニッケル組織中に同一レベルのWO3粒子が分散していることが電子顕微鏡とEDSにより確認できた。また、結晶粒径が同レベルのナノ結晶ニッケルに比較してさらに硬度上昇と熱的安定性の向上が確認できた。, 日本学術振興会, 科学研究費助成事業 新学術領域研究(研究領域提案型), 2013/04 -2015/03, 新学術領域研究(研究領域提案型), 同志社大学
電着法による強度と熱的安定性が卓越したナノ粒子分散型バルクナノ金属の創成
宮本 博之
昨年度は、電解液にWO3粒子を懸濁させた電析共析法により、粒径が約40nmの母相ナノ結晶ニッケル中に10nm以下のWO3粒子が分散したナノ粒子分散ナノ結晶ニッケルを合成することに成功した。結晶粒径が同程度のナノ結晶組織を有する純ニッケルよりもビッカース硬度にて100HV程度硬化していたが、析出強化機構(オロワン機構)から推定される硬度上昇には至らなかった。この結果を受けて,今年度は分散粒子径や分散量、母相結晶粒径を系統的に変化させて強化機構を明らかにする予定であったが, 分散粒子の凝集や偏在の問題が解決できなかった. そこで、析出反応系であるNi-P合金を用いて、時効強化による研究を行った。電解液を種々検討することにより、Ni3P析出量を制御しつつ母相ニッケル結晶粒径を10ミクロン程度から100nm以下まで系統的に変化させることが可能になった。その結果は同レベルP含有量について結晶粒径がナノオーダーまで微細化すると析出強化による硬化量がミクロンオーダーの結晶粒径を有する場合に比較して低下することが明らかになった。すなわち、ナノ結晶材料では粒界関与型の変形機構に変化するため、いわゆる転位阻止型の析出機構は有効に作用しないと考えられる。, 日本学術振興会, 科学研究費助成事業 新学術領域研究(研究領域提案型), 2011/04 -2013/03, 新学術領域研究(研究領域提案型), 同志社大学
Texture control for high formability of ferritic stainless steel by combined processing of ECAP and cold-rolling
MIYAMOTO Hiroyuki
Equal-channel angular pressing (ECAP) was applied to 16mass%Cr steel sheets for one pass prior to cold rolling in order to improve formability and alleviate ridging of the sheets. Effect of channel angle of ECAP (90° and 120°) on the deformation microstructure and the subsequent recrystallization was focused. One-pass ECAP indeed modified the cold-rolled microstructures, texture and subsequent recrystallization as compared with that in cold rolling alone. In particular, grain-scale shear bands were introduced during ECAP in otherwise hard-to-recrystallize <001>//ND grains by ECAP, and they facilitated the recrystallization. However, the effect of reducing the channel angle from 120°to 90°on the recrystallization and the formability was limited in spite of higher shear strain imposed on the sheets., Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), 2010 -2012, Grant-in-Aid for Scientific Research (C), Doshisha University
Wide-area SEM observation of dislocation structures and the restructuring of fracture estimation model
HASHIMOTO Satoshi; KANEKO Yoshihisa; VINOGRADOV Alexei; NAKAMURA Atsutomo; MIYAMOTO Hiroyuki
Microstructures of metallic materials fractured under various conditions were analyzed using the electron channelling contrast imaging (ECCI) technique which enables us to observe dislocation in a scanning electron microscope, and the electron backscatter diffraction (EBSD) technique. Based on the microstructure analyses, we developed the method to determine fracture process, and investigated factors which determine crack propagation path and crack initiation site. Fatigue damage of ultrafine-grained materials could also be estimated with these techniques., Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), 2007 -2009, Grant-in-Aid for Scientific Research (A), Osaka City University
Reduction of Grain boundary energy to stabilize ultra-fine grain structure produced by severe plastic deformation
MIYAMOTO Hiroyuki; MIMAKI Takuro
等径角付き押し出し(Equal-Channel Angular Pressing : ECAP)法により超微細結晶化したα黄銅(Cu-10wt%Zn)について応力腐食割れ(Stress Corrosion Cracking : SCC)感受性を評価し, 結晶粒径の影響, 平衡・非平衡粒界の影響を明らかにする事を目的とした. 強ひずみ加工法の一つであるECAP法により室温で8パス加工することにより, 結晶粒径が平均約100nmまで微細化することに成功した. 8パス加工材ではECAP加工後に200℃で40秒の短時間熱処理を行った. 強ひずみ加工で形成した粒界は過剰な転位を有する非平衡粒界と考えられており, この熱処理により過剰な転位は回復し, 平衡粒界に変化すると考えられる. さらに比較として, ECAP加工しない0パス材, 加工硬化を目的とした1パス材を評価した. SCC試験は, I型試験片により室温(約290K), 14%NH_3雰囲気中に一定ひずみのもとで24時間放置した後のき裂長さを評価した
SCC試験の結果, 8パスした超微細結晶材は0パス材、1パス材に比べて、σ/σys(σは負荷応力,σysは0.2%耐力)が低い値でき裂の発生が確認された. また、ECAP加工後の短時間熱処理によりき裂が発生する応力が高くなり、SCC感受性が低下することが明らかとなった. ECAP加工などの強ひずみ加工では結晶粒の微細化とともに結晶粒界が非平衡となり、粒界エネルギが高くなったことがSCC感受性の高まった原因だと考えられる. なと、熱的安定性については有意な差は確認されなかった, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), 2007 -2008, Grant-in-Aid for Scientific Research (C), Doshisha University
A study on the clarification of formation mechanism, environmental embrittlement and fatigue behavior of nanocrystals
MIMAKI Takuro; MIYAMOTO Hiroyuki
Ultra-fine grain copper samples were produced by ECAP (Equal-Channel angular pressing) technique using well-oriented copper single crystals having, <001>, <011>. and <111> axis direction. The investigations were performed during the formation of ultra-fine crystals by severe plastic deformation. The fining process in the formation of ultra-fine grains was divided to the following three groups ; (1)Shear bands were formed parallel to the shear direction of the initial single crystal inserted, (2)Deformation bans were deformed to the insert direction of the single crystal and (3)Both bands described above were not formed. The dislocation structure of the shear band were formed by very dense and tuft-like microbands and the mirror relationship was observed between the microband and the matrix. From a detailed TEM observation, the deformation twins with about 200 nm width were observed. The formation mechanism of the deformation twin was clarified as the "Pole mechanisms".
From the investigations on behavior of crack initiation and propagation, it was clarified that crack initiation and propagation mode were intergranular type and tendency of the relation between stress intensity factor and crack propagation rate was divided to two regions as same as the practical use materials. The SCC sensitivity was extremely decrease by the crystal fining. The cracks in specimen produced from single crystals were branched off to many direction, snaked and it takes much time to propagate, compared with the specimen produced from polycrystals.
Impact test was performed using ultra-fine grained aluminum. From the results, the impact strength of the ultra-fine grained aluminum was 1.6〜2.3 times higher than the practical use aluminum. Under both room and very low temperature, 77K, the impact strength was showed the very clear strain rate dependence, and the impact strength was increased with strain rate increasing.
These results described above were already published in Phil.Mag.Letters, Scripta Materialia, Mater. Sci. & Engg. and etc., Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), 2004 -2005, Grant-in-Aid for Scientific Research (C), Doshisha University
集合組織制御した微細粒二相ステンレス鋼板の超塑性
橋本 敏; 宮本 博之; 加藤 博之; 御牧 拓郎
二相ステンレス鋼は微細粒超塑性を示す代表的な金属材料であり、一般的に微細粒超塑性においては粒界すべりおよび相界面すべりが支配的な機構であることが知られている。著者らはγ(FCC)/α(BCC)ステンレス鋼異相双結晶等を用いたクリープ試験からγ/α相界面は本質的に単相粒界に比べてすべり易いことを明らかにした[1,2]。一方、単相の粒界すべりは方位関係の影響を受けることが純Zn、Al等について報告されていることから相界面すべりについてもγ相/α相の方位関係の影響を受けることが予想される。そこで本研究では異相間の方位関係分布の定性的指標となる各相の集合組織が二相ステンレス鋼板の超塑性変形挙動に及ぼす影響を明らかにすることを目的とする。本年度は第一段階として他に報告されているα(FCC)/β(BCC)Brass等の双結晶クリープの実験データも加えてFCC/BCC相界面すべり機構の理論的検討を行い[3]、さらに相界面と単相粒界における本質的なすべり易さの違いを含めた二相(FCC/BCC)鋼の変形機構を提案し[4]、これまで報告されてきた実験データにより検証をおこなった。
双結晶を用いたクリープ試験から、変形抵抗が異なるFCC相およびBCC相から構成される相界面と単相粒界におけるすべり抵抗の顕著な差異が明らかとなった。この知見より超塑性変形における相界面の役割として、相界面すべりにより超塑性ひずみの大部分を請け負う変形モデルを提案した。これは第二相が変形中に粒成長を抑制し微細組織を安定化するという従来の役割とは異なる視点から変形機構を示唆するものである。, 日本学術振興会, 科学研究費助成事業 特定領域研究(A), 1998 -1998, 特定領域研究(A), 京都大学
Emvironmental embrittlement of ultra-fine grain materials
Grant-in-Aid for Scientific Research, 1997, Competitive research funding
超微細結晶材料の環境脆化
科学研究費補助金, 1997, Competitive research funding