Effects of grinding and uniaxial press-forming on sintered superconductor in the Bi-Pb-Sr-Ca-Cu-O system

Hideaki Itoh, Setsuo Yada, Shigeharu Naka, Jun Takada, Yoichi Tomii, Mikio Takano

Research output: Contribution to journalArticle

Abstract

The formation of an amorphous phase in grinding and its recrystallization behavior by heat treatment were observed using a starting powder of the high Tc phase (2223 phase) superconductor having the composition Bi1.8Pb0.4Sr2.0Ca2.0Cu3.2Oy. The effects of uniaxial press-forming were investigated in relation to the properties of sintered compacts (bulk density, phase microstructure, critical temperature, etc.). Grinding the starting powder for 10-20 min initiated formation of an amorphous phase and a nearly completely amorphous phase was obtained by grinding for 100 min. Heat treatment (at 850°C for 2h), resulted in recrystallization to high Tc phase (2223 phase) in the presence of a trace of low Tc phase (2212 phase). Starting powder packed in a copper ring gasket was press-formed under high pressure (0.5-1.5 G Pa). A small amount of low Tc phase coexisted with high Tc phase in the specimen formed at 1.0 G Pa. The bulk density of the sintered compact prepared by sintering at 850°C for 40h under one atmospheric pressure was 5.4g/cm3. The critical onset and offset temperatures were 115K and 103K, respectively.

Original languageEnglish
Pages (from-to)233-236
Number of pages4
JournalFuntai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy
Volume38
Issue number2
Publication statusPublished - Feb 1991
Externally publishedYes

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Powders
Superconducting materials
Heat treatment
Atmospheric pressure
Copper
Sintering
Temperature
Microstructure
Chemical analysis

ASJC Scopus subject areas

  • Mechanical Engineering
  • Metals and Alloys

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Effects of grinding and uniaxial press-forming on sintered superconductor in the Bi-Pb-Sr-Ca-Cu-O system. / Itoh, Hideaki; Yada, Setsuo; Naka, Shigeharu; Takada, Jun; Tomii, Yoichi; Takano, Mikio.

In: Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy, Vol. 38, No. 2, 02.1991, p. 233-236.

Research output: Contribution to journalArticle

Itoh, Hideaki ; Yada, Setsuo ; Naka, Shigeharu ; Takada, Jun ; Tomii, Yoichi ; Takano, Mikio. / Effects of grinding and uniaxial press-forming on sintered superconductor in the Bi-Pb-Sr-Ca-Cu-O system. In: Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy. 1991 ; Vol. 38, No. 2. pp. 233-236.
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