摘要
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/(m.K),400K附近热导率又增大至920W/(m.K)。在不改变接触点的前提下,通过测量同一根纤维不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 100-400K 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 300 K, and saturated around 350 K at a value of about 800 W/（m·K）. An unexpectedly 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%.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2008年第3期259-263,共5页
New Carbon Materials
基金
National Nature Science Foundation of China(50676046)~~
关键词
“T”形法
热导率
单根沥青基炭纤维
T type method
Thermal conductivity
Individual pitch-derived fibers
