Influence of Particle Size of Mg Powder on the Microstructure and Critical Currents of <i>In Situ</i> Powder-in-tube Processed MgB<sub>2</sub> Wires

DOI Web Site Web Site 1 Citations 15 References Open Access
  • Kumakura Hiroaki
    Superconducting Wires Unit, National Institute for Materials Science
  • Ye Shujun
    Superconducting Wires Unit, National Institute for Materials Science
  • Matsumoto Akiyoshi
    Superconducting Wires Unit, National Institute for Materials Science
  • Nitta Ryuji
    Superconducting Wires Unit, National Institute for Materials Science

Bibliographic Information

Other Title
  • <i>In Situ</i> パウダー・イン・チューブ法で作製した MgB<sub>2</sub> 線材の組織と臨界電流に及ぼす Mg 粉末粒径の影響
  • In Situパウダー・イン・チューブ法で作製したMgB₂線材の組織と臨界電流に及ぼすMg粉末粒径の影響
  • In Situ パウダー ・ イン ・ チューブホウ デ サクセイ シタ MgB ₂ センザイ ノ ソシキ ト リンカイ デンリュウ ニ オヨボス Mg フンマツ リュウケイ ノ エイキョウ
Published
2016
DOI
  • 10.2320/jinstmet.jc201606
Publisher
The Japan Institute of Metals and Materials

Search this article

Description

We fabricated in situ powder-in-tube(PIT) MgB2 wires using three kinds of Mg powders with particle size of ~45 μm, ~150 μm and 212~600 μm. Mg particles were elongated to filamentary structure in the wires during cold drawing process. Especially, long Mg filamentary structure was obtained for large Mg particle size of 212~600 μm. Critical current density, Jc, increased with increasing Mg particle size for 1 mm diameter wires. This is due to the development of filamentary structure of high density MgB2 superconducting layer along the wires. This MgB2 structure is similar to that of the internal Mg diffusion(IMD) processed MgB2 wires. However, Jc of the wires fabricated with 212~600 μm Mg particle size decreased and the scattering of Jc increased with decreasing wire diameter, while the Jc of the wires with ~45 μm Mg particle was almost independent of the wire diameter. The cross sectional area reduction of the Mg particles during the wire drawing is smaller than that of the wire. When using large size Mg particle, the number of Mg filaments in the wire cross section is small. These two facts statistically lead to the larger scattering of Mg areal fraction in the wire cross section with proceeding of wire drawing process, resulting in smaller volume fraction of MgB2 in the wire and lower Jc with larger scattering along the wire. SiC nano powder addition is effective in increasing Jc for all Mg particle sizes.<br>

Journal

Citations (1)*help

See more

References(15)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top