Mechanical Dissolution of Cu<sub>5</sub>Zr Phase and Formation of Supersaturated Solid–Solution Nanocrystalline Structure by High–Pressure Torsion in a Hypoeutectic Cu–2.7at%Zr Alloy

DOI Web Site Open Access
  • Miyamoto Kenta
    Division of Mechanical Science and Engineering, Graduate School of Natural Science and Technology, Kanazawa University
  • Kunimine Takahiro
    Faculty of Mechanical Engineering, Institute of Science and Engineering, Kanazawa University
  • Watanabe Chihiro
    Faculty of Mechanical Engineering, Institute of Science and Engineering, Kanazawa University
  • Monzen Ryoichi
    Faculty of Mechanical Engineering, Institute of Science and Engineering, Kanazawa University
  • Gholizadeh Reza
    Department of Materials Science and Engineering, Kyoto University
  • Tsuji Nobuhiro
    Department of Materials Science and Engineering, Kyoto University

Bibliographic Information

Other Title
  • 亜共晶Cu–2.7at％Zr合金における高圧ねじり加工によるCu<sub>5</sub>Zr相の消失と過飽和固溶体ナノ結晶組織の形成
  • 亜共晶Cu-2.7at%Zr合金における高圧ねじり加工によるCu₅Zr相の消失と過飽和固溶体ナノ結晶組織の形成
  • アキョウショウ Cu-2.7at%Zr ゴウキン ニ オケル コウアツネジリ カコウ ニ ヨル Cu ₅ Zrソウ ノ ショウシツ ト カホウワコヨウタイ ナノ ケッショウ ソシキ ノ ケイセイ

Search this article

Abstract

<p>Microstructural evolution and changes in hardness and electrical conductivity of a cast hypoeutectic Cu–2.7at%Zr alloy processed by high–pressure torsion (HPT) were investigated. The cast alloy had a net–like microstructure composed of a primary Cu phase and a eutectic consisting of layered Cu and Cu5Zr phases. The Cu and Cu5Zr phases in the eutectic had a cube–on–cube orientation relationship. The cast alloy with the hardness of 137 HV exhibited a value of electrical conductivity of 32%IACS. With increasing the number of HPT–revolutions, the eutectic was severely sheared and elongated along the rotational direction. In addition, mechanical dissolution of the Cu5Zr phase into the Cu phase by HPT was confirmed after 5 HPT–revolutions through XRD measurements and TEM observations. After 20 HPT–revolutions, the Cu phase was significantly refined and formed the lamellar structure having an average grain size of 15 nm. The electrical conductivity decreased and saturated at a value of 8%IACS after 50 HPT–revolutions. The significant decrease in the electrical conductivity was primarily attributable to the mechanical dissolution of the Cu5Zr phase into the Cu phase by HPT, followed by the formation of nanocrystalline Cu–Zr supersaturated solid–solution alloy with the hardness of 430 HV.</p>

Journal

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top