热塑性复合材料等效导热系数测定方法

为了提高热塑性复合材料的导热性,为热塑性复合材料的开发与应用提供依据,研究了一种热塑性复合材料等效导热系数测定方法。将聚酰亚胺模塑粉、胶体石墨和炭纤维作为原料,制备热塑性复合材料,搭建复杂环境下导热系数测试实验平台,通过稳态法对理论上单一材料的导热系数进行计算。把填料转换成体积含量,研究热塑性复合材料导热性能,发现填充石墨和炭纤维的热塑性复合材料导热性能有很大的不同,需研究一种通用的热塑性复合材料等效导热系数测定方法。生成等效结构,在此基础上,依据常物性、无内热源与稳态热传导对热塑性复合材料等效导热系数进行测定,利用从底向上的计算方式求出等效导热系数。通过实验测试平台测量炭纤维填充热塑性复合材料和石墨填充热塑性复合材料,结果表明,所提测定结果基本分布于实测数据周围。通过人为添加满足正态分布的实验误差当成实验测量值对等效导热系数进行测定,所提方法可在测量误差情况下给出准确的热塑性复合材料等效系数测定结果。可见所提方法测定结果准确。

Study on Measuring Method of Equivalent Thermal Conductivity of Thermoplastic Composites

In order to improve the thermal conductivity of thermoplastic composites and provide basis for the development and application of thermoplastic composites, a method for determining the equivalent thermal conductivity of thermoplastic composites was studied. Thermoplastic composites were prepared by using polyimide molding powder, colloidal graphite and carbon fibers as raw materials. An experimental platform for measuring thermal conductivity in complex environment was built. Thermal conductivity of a single material was calculated theoretically by steady-state method. The thermal conductivity of thermoplastic composites filled with graphite and carbon fibers is very different. A general method to determine the equivalent thermal conductivity of thermoplastic composites is needed. On the basis of the equivalent structure, the equivalent thermal conductivity of thermoplastic composites was determined according to the constant physical properties, no internal heat source and steady state heat conduction. The equivalent thermal conductivity was calculated from bottom to top. Carbon fiber filled thermoplastic composites and graphite filled thermoplastic composites were measured by an experimental platform. The results show that the measured results are basically distributed around the measured data. The equivalent thermal conductivity of thermoplastic composites is measured by adding experimental errors satisfying normal distribution. The results show that the proposed method can give accurate results of the equivalent thermal conductivity of thermoplastic composites under measurement errors. It can be seen that the results of the proposed method are accurate.