采用"T"形法测量了温度100K～400K范围内单根沥青基炭纤维的热导率.结果表明,在300K以下,由于边界散射的影响,炭纤维热导率随着温度升高而增大,350K左右渐趋于饱和,对应热导率约为800W/(in·K),400K附近热导率又增大至920W/(in·K).在不改变接触点的前提下,通过测量同一根纤维小同长度对应的热导率,估计了炭纤维与热线节点处的接触热阻,并讨论了不同温度下辐射对热导率测量的影响,最后得到热导率的测量不确定度在±13%以内.
The thermal conductivity of individual pitch-derived carbon fibers was measured in the temperature range 100-400 K by a T type method, in which a hot wire served both as a heating source and thermometer, and the electrical and thermal properties of the hot wire were measured by direct current heating. When a tested carbon fiber was attached to the center position of the hot wire, the thermal conductivity of the fiber was determined by a comparison of the ave-rage temperature rise of the hot wire with and without the fiber. Results show that the thermal conductivity of the fiber was limited by boundary scattering below 300K, and saturated around 350K at a value of about 800W/(m·K). An un-expectedly high thermal conductivity of about 920W/(m·K) was observed at around 400 K. The effect of the thermal contact resistance on the measurement was estimated by changing the length of the fiber in the same contact conditions and the radiation effect was also discussed. The uncertainty of the thermal conductivity was estimated to be±13%.
参考文献
| [1] | Piraux B;Nysteu L;Issi J P .Thermal conductivity of pitch-derived fibres[J].Journal of Physics D:Applied Physics,1985,18:1307-1310. |
| [2] | Zhang X;Fujiwara S;Fujii M .Measurements of thermal conductivity and electrical conductivity of a single carbon fiber[J].International Journal of Theoretical Physics,2000,21(04):965-980. |
| [3] | Yamane T.;Todoki M.;Hatta I.;Katayama S. .THERMAL DIFFUSIVITY MEASUREMENT OF SINGLE FIBERS BY AN AC CALORIMETRIC METHOD[J].Journal of Applied Physics,1996(8):4358-4365. |
| [4] | Barkyoumb J H;Land D J .Thermal diffusivity measurement of thin wires using photothermal deflection[J].Journal of Applied Physics,1995,78(02):905-912. |
| [5] | Houedec H Le;Rochais D;Enguehard F et al.Microscopic thermal characterization at temperature up to 1000℃ by photoreflectance microscopy[J].Superlattices and Microstructures,2004,35:401-408. |
| [6] | 马维刚 ."T"形法测量单根碳纤维的热导率[D].北京:清华大学,2006. |
| [7] | David R L.CRC Handbook of Chemistry and Physics[M].Boca Raton:crc Press,2004:12-46. |
| [8] | Kannuluik W G;Carman E H .The thermal conductivity of rare gases[J].Proceedings of the Physical Society Section B,1952,65:701-709. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%