15–19 Nov 2021
Fukuoka Convention Center
Asia/Tokyo timezone

Physical properties of all c-grown Gd123 bulks starting from various metal compositions

THU-PO3-612-06
18 Nov 2021, 10:00
2h
Fukuoka Convention Center

Fukuoka Convention Center

Speaker

Mr Takuma Tomihisa (Aoyama Gakuin University)

Description

REBa2Cu3Oy(RE123, RE: rare earth element) melt-textured bulks are used as superconducting magnets using their high field trapping (BT) properties. Their BT performances are enhanced by both enhancement of critical current density (Jc) and an increase in size of the bulks. We prepared all c-grown Gd123 melt-textured bulks grown on a Eu123 melt-textured bulk as a seed plate using newly developed Single-Direction Melt Growth (SDMG) method. This method is particularly unique in that RE123 melt-textured bulks are grown only vertically from the seed plate cut from the large RE123 melt-textured bulks having higher peritectic temperatures. Therefore, melt growth proceeds in one direction on a large bulk plate, which enables both flexibility in shapes and short-time fabrication of large bulks. In this study, improvement of BT properties by control of starting metal composition and additions of pre-sintering or pre-melting process prior to the melt-growth was attempted. Jc-B properties of small pieces cut from bulks starting from Ba-rich compositions (Gd : Ba : Cu = 1.25 : 1.75+x : 2.5 (Gd123 : Gd211 = 7.5 : 2.5), x > 0) were improved compared with standard Gd123 bulks with x = 0, suggesting that RE/Ba substitution was suppressed by excess Ba compositions. In addition, introduction of the pre-melting process (1055°C in air) was more effective to achieve high Jc rather than introduction of pre-sintering process (960°C in air). Improved BT distributions of Gd123 bulks grown by SDMG method will be also shown.

Primary author

Mr Takuma Tomihisa (Aoyama Gakuin University)

Co-authors

Dr Takanori Motoki (Aoyama Gakuin University) Mr Rempei Sasada (Aoyama Gakuin University) Prof. Jun-ichi Shimoyama (Aoyama Gakuin University)

Presentation materials

There are no materials yet.