ECAP法で作製した超微細粒合金の組織安定性とホール・ペッチの関係

1998 Fiscal Year Annual Research Report

• Project/Area Number: 09650764
• Research Institution: Fukuoka University of Education
• Principal Investigator: 古川 稔 福岡教育大学, 教育学部, 助教授 (90112276)
• Keywords: ECAP法 / 強ひずみ加工法 / 超微細結晶粒 / 組織安定性 / 電子顕微鏡観察 / ホール・ペッチの関係 / 超塑性特性

Research Abstract

ECAP法で作製した微細結晶粒径のAl合金について、組織の熱的安定性、ホール・ペッチの関係および超塑性特性を調べた。
1. ECAP後の粒径と加熱後の組織安定性:純Al、Al-3%Mg合金、Al-0.2%Zr合金、Al-0.2%Sc合金、Al-3%Mg-0.2%Sc合金、Al-5.5%Mg-2.2%Ll-0.12%Zr合金をECAPすることにより、それぞれ1.2、0.3、0,7、0.7、0.2、1.2μmの微細粒が得られた。純AlとAl-3%Mg合金では微細粒は473Kまで安定していた。Al-0.2%Zr合金では573Kまで、Al-0.2%Sc合金とAl-3%Mg-0.2%Sc合金では673Kまで微細粒が保たれた。ZrやScを含む合金が純AlやAl-Mg合金より高温まで微細粒の熱的安定性を保つ原因は、微細なL1_2規則粒子Al_3ZrとAl_33Scの存在によるものであり、Al_3ScはAl_3Zrよりもより高温までAl合金に対する再結晶抑制効果が顕著であることを示している。Al-5.5%Mg-2.2%Ll-0.12%Zr合金では、微細粒は673Kまで安定に保たれた。
2. ホール・ペッチの関係:Al-3%Mg合金では、結晶粒径0.2〜100μmの範囲でHv=46+35d^<-1/2>、Al-5.5%Mg-2.2%Li-0.12%Zr合金では、2〜60μmの範囲でHv=75+27d^<-1/2>(Hvはビッカース硬度、dは結晶粒径)の関係が成り立った。
3. 超塑性特性:ECAPしたAl-3%Mg-0.2%Sc合金では673K、3.3x10^<-2>s^<-1>の条件で1030%、Al-5.5%Mg-2.2%Li-0.12%Zr合金では623K、10^<-2>S^<-1>の条件で1200%以上超塑性伸びを示した。破断部の結晶粒はつかみ部に比べて大きくなっており、応力誘起により粒成長が起こっていることがわかった。

Research Products

• [Publications] M.Furukawa: "Microstructural Characteristics of an Ultrafine Grain Metal Processed with Equal-Channel Angular Pressing" Materials Characterization. Vol.37. 277-283 (1997)
• [Publications] Z.Horita: "Evolution of Grain Boundary Structure in Submicrometer-Grained Al-Mg Alloy" Materials Characterization. Vol.37. 285-294 (1997)
• [Publications] M.Furukawa: "Recrystallization in Ultrafine-Grained Materials with Non-Eguilibrium Grain Boundaries" Proceedings of the Third International Conference on Recrystallization and Related Phenomena(Rex'96). 149-160 (1997)
• [Publications] M.Furukawa: "Structural Evolution and the Hall-Petch Relationship in an Al-Mg-Li-Zr Alloy with Ultra-Fine Grain Size" Acta Metallurgica et Materialia. Vol.45,No.11. 4751-4757 (1997)
• [Publications] M.Furukawa: "Microstructural Characteristics and Superplastic Ductility in a Zn-22% Al Alloy with Submierometer Grain size" Materials Science and Engineering A. Vol.A241,No.1〜2. 122-128 (1998)
• [Publications] M.Furukawa: "Age Hardening and the Potential for Superplasticity in a Fine-Grained Al-Mg-Li-Zr Alloy" Metallurgical and Materials Transactions A. Vol.29A January. 169-177 (1998)
• [Publications] M.Furukawa: "Fabrication and Properties of a Submicrometer-Grained Zn-22%Al Alloy" Proceedings of International Conference on Thermomechanical Processing of Steels and Other Materials,Thermec'97. 1875-1881 (1998)
• [Publications] Z.Horita: "Characterization of Ultra-Fine Grained Materials Produced by Torsion Straining" Proceedings of International Conference on Thermomechanical Processing of steels and Other Materials,Thermec'97. 1937-1943 (1998)
• [Publications] P.B.Berbon: "Superplasticity in Alloys Processed by Equal-Channel Angular Pressing." Superplasticity and Superplastie Forming'1998. 127-134 (1998)
• [Publications] M.Furukawa: "Microstructural Evolution in Pure Aluminum During Equal-Channel Angular Pressing." Modeling the Mechanical Response of Structural Materials. 165-172 (1998)
• [Publications] P.B.Berbon: "Application of Equal-Channel Angular Pressing for Producing Superplastic Alloys" Modeling the Mechanical Response of Structural Materials. 173-180 (1998)
• [Publications] 小林章吾: "拘束強ひずみ加工で作製した超微細粒組織" 日本金属学会会報(まてりあ). 第37巻 第5号. 376-376 (1998)
• [Publications] T.G.Langdon: "Using Intense Plastic Straining for High-Strain-Rate Super plasticity" Journal of Materials(JOM). Vol.50,No.6. 41-45 (1998)
• [Publications] M.Furukawa: "Factors Influencing the Flow and Hardness of Materials with Ultrafine Grain Sizes" Philosophical Magazine A. Vol.78,No.1. 203-215 (1998)
• [Publications] S.Komura: "High Strain Rate Superplasticity in an Al-Mg Alloy Containing Scandium." Scripta Metallurgiea et Materialia. Vol.38,No.12. 1851-1856 (1998)
• [Publications] H.Hasegawa: "Grain Refinement and Potential for Superplasticity in Al Alloys Containing Small Partieles." Proceedings of the Third Pacific Rim International Conference on Advanced Materials and Processing (PRICM-3). 1873-1878 (1998)
• [Publications] K.Oh-ishi: "Optimizing the Rotation conditions for the Grain Refinement in Equal-Channel Angular Pressing" Metallurgical and Materials Transactions A. Vol.29A July. 2011-2013 (1998)
• [Publications] P.B.Berbon: "Optimizing the Processing of a Commercial Al-Based Alloy for High Strain Rate Superplasticity" Proceedings of the Third International Symposium on Microstructures and Mechanical Properties of New Engineering Materials (IMSP'97). 81-88 (1998)
• [Publications] P.B.Berbon: "Fabrication of Bulk Ultrafine-Grained Materials Through Intense Plastic Straining" Metallurgical and Materials Transactions A. Vol.29A September. 2237-2243 (1998)
• [Publications] Y.Iwahashi: "Microstructural Charaeteristies of Ultrafine-Grained Aluminum Produced Using Equal-Channel Angular Pressing." Metallurgical and Materials Transactions A. Vol.29A September. 2245-2252 (1998)
• [Publications] 堀田善治: "新しい組織制御法としてのEqual-Channel Angular Pressing(ECAP)" 日本金属学会会報(まてりあ). 第37巻 第9号. 767-774 (1998)
• [Publications] P.B.Berbon: "Requirements for Achieving High Strain Rate Superplasticity in Cast Aluminum Alloys" Philosophieal Magazine Letters. Vol.78,No.4. 313-318 (1998)
• [Publications] P.B.Berbon: "Processing of Aluminum Alloys for High Strain Rate Superplastieity" Hot Deformation of Aluminum Alloys II. 111-124 (1998)
• [Publications] S.Komura: "Super plastieity in an Ultrafine-Grained Al-Mg-Se Alloy Produced by Equal-Channel Angular Pressing." Hot Deformation of Aluminum Alloys II. 125-138 (1998)