Fabrication of high strength and high electrical conductivity Al alloy through supersaturation of Fe by High-Pressure Torsion

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15324
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: Yokohama National University
• Principal Investigator: Masuda Takahiro 横浜国立大学, 大学院工学研究院, 日本学術振興会特別研究員 (60838639)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 巨大ひずみ加工 / 過飽和固溶体 / 結晶粒微細化

Outline of Final Research Achievements

In this study, the process of high-pressure torsion (HPT) is applied for grain refinement of an Al-2% Fe alloy in a ring shape with a diameter of 100 mm, and thus we can obtain the homogeneous strain distribution. After only 1 turn, the Fe solubility in the Al matrix was increased to 1wt%. The ultimate tensile strength was increased up to 730 MPa after aging at 473 K. Considering the electrical conductivity, 0.25 turns is effective to attain the balance between strength and electrical conductivity. CHPT was further developed in this study, so that two wires were processed simultaneously. Guiding holes were made at both the inlet and outlet sides of the grooves on the upper anvils so that no interference of the two wires occurs. An equivalent strain of 25 was introduced through this CHPT process.

Free Research Field

材料組織制御

Academic Significance and Societal Importance of the Research Achievements

これまで巨大ひずみ加工領域の大面積化には装置容量の限界という問題があった。本研究により、２本のワイヤー試料に連続的なひずみ導入のための加工原理を構築した。かつAl-Fe系合金にて鉄の過飽和固溶・析出を利用した特性向上を達成し、超微細粒を有する電線材料の開発可能性を示した。さらに、各ワイヤーの加工直径を調整することで、同時加工数を増大できる可能性を示し、巨大ひずみ加工法の一般化に繋がる結果を得られた。