Abstract
Superconducting test coils impregnated with epoxy composites containing cubic boron nitride (cBN) particles, hexagonal boron nitride (hBN) particles, and a mixture of cBN/hBN particles were fabricated, and their thermal and electrical properties were investigated using cool-down, over-current, and repetitive-cooling tests. Micro-voids, which may act as major obstacles to the formation of thermally conductive passages, were observed in the epoxy composites containing the cBN or hBN particle fillers alone but were absent in that containing the cBN/hBN particle mixture. The coil impregnated with epoxy containing the cBN/hBN particle mixture also exhibited superior cooling performance and thermal/electrical stabilities, indicating that this composite effectively facilitated heat transfer between the coil and liquid nitrogen. Moreover, the addition of the cBN/hBN filler reduced the difference in thermal contraction between the superconducting tape and epoxy composite. Overall, the use of the epoxy composite containing the cBN/hBN filler shows potential for the development of highly stable superconducting coils with considerably enhanced thermal conductivity and low coefficients of thermal expansion.
| Original language | English |
|---|---|
| Pages (from-to) | 22-28 |
| Number of pages | 7 |
| Journal | Composites Part B: Engineering |
| Volume | 107 |
| DOIs | |
| Publication status | Published - 2016 Dec 15 |
Bibliographical note
Funding Information:This work was supported by the Materials and Components Technology Development Program of KEIT [ 10053590 , Development of MgB 2 wire and coils with high critical currents and long length for superconducting medical·electric power equipment].
Keywords
- Boron nitride filler
- Electrical properties
- Polymer-matrix composites (PMCs)
- Resins
- Thermal properties
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials
- Mechanical Engineering
- Industrial and Manufacturing Engineering