2011 Fiscal Year Final Research Report
Development of high performance MgB2 wires by Mg diffusion method
| Project/Area Number |
21560764
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Material processing/treatments
|
|---|
| Research Institution | National Institute for Materials Science |
|---|
Principal Investigator |
KUMAKURA Hiroaki 独立行政法人物質・材料研究機構, 強磁場ステーション, ステーション長 (90354307)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MATSUMOTO Akiyoshi 独立行政法人物質・材料研究機構, 超伝導線材ユニット, 主幹研究員 (50354303)
TOGANO Kazumasa 独立行政法人物質・材料研究機構, 超伝導線材ユニット, 研究業務員 (60361169)
|
|---|
| Project Period (FY) |
2009 – 2011
|
| Keywords | 拡散法 / 塑性加工 / 充填率 / 空隙 / 多芯線材 / 臨界電流密度 |
|---|
| Research Abstract |
We have fabricated single-to 37-filamentary MgB_2 wires applying an internal Mg diffusion process. The billet composed of Mg rod/B powder layer/metal sheath could be uniformly cold worked into wire with 1-1.5mm diameter at room temperature. During the heat treatment Mg at the center of filaments diffused to B layers and reacted with B to form MgB_2 layers. The packing density of this MgB_2 layer was much higher than that of conventional PIT processed MgB_2 wires. The optimum heat treatment temperature for 7-filamentary wire was 640℃, and critical current density J_c value reached to almost 1x10^3A/mm^2 at 4.2K and 10T and 1.3x10^3A/mm^2 in 3T at 20K. These J_c values are now the highest value among the MgB_2 wires. 19-and 37-filamentary wires showed somewhat lower J_c values than 7-filamentary wire due to less uniformity of reacted layers along the wire length.
|
