Microstructural changes of oxide dispersion strengthened copper powders fabricated by mechanical alloying

Yusuke Shimada, Masataka Mizumoto, Yoshimitsu Hishinuma, Ken ichi Ikeda, Kenta Yoshida, Hiroyuki Noto, Bing Ma, Takeo Muroga, Yasuyoshi Nagai, Toyohiko J. Konno

Research output: Contribution to journalArticlepeer-review

Abstract

Oxide dispersion strengthened Cu alloys (ODS-Cu) having dispersed yttria (Y2O3) fabricated using hot isostatic pressing (HIP) of mechanically alloyed (MA) Cu-Y powders. They exhibited a heterogeneous mixed grain structure, which were composed of a large and small Cu grain area. In the small Cu grain regions, Y₂O₃ particles were segregated along the grain boundaries, and acted as a crack propagation path, leading to brittle fracture. Therefore, we investigated the microstructural changes by the MA and heat treatment processes for the microstructure optimization. The powders of 4 to 32 MA hours formed a nested crust-like layered structure with large and small Cu grains. The layers were destroyed by heat treatment at 500°C, because recrystallization and grain growth of Cu occurred in the temperature range of 310 - 330°C. It was considered that Y2O3 was moved out to the circumferential area of the powders. Based on these results, it was suggested that the structural changes inside MA powders during HIP are the essential factor of the Y2O3 distribution within the Y2O3-added ODS-Cu alloys.

Original languageEnglish
Article number112804
JournalFusion Engineering and Design
Volume173
DOIs
Publication statusPublished - 2021 Dec

Keywords

  • Mechanical alloyed powder
  • Microstructure
  • Oxide dispersion strengthened Cu alloy

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

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