中文摘要：

对膨胀石墨在不同膨胀温度及不同膨胀时间下进行了膨胀工艺与导热系数测试的研究。研究中,分别用平面热源法和称重法测出不同膨胀条件下石墨的导热系数和密度。然后根据导热系数最优化的原则,结合未膨胀晶体的观测状态以及密度的变化,找出膨胀石墨的最佳膨胀工艺。结果发现膨胀石墨在各个膨胀温度下都存在着自己的最佳膨胀工艺。经过不同膨胀温度条件下同等密度样品的对比发现,膨胀温度在600℃时膨胀10 min导热系数达到了最大值,其值为0.09498 W·（m·K）-1。这个值相对于500℃、700℃以及800℃的最优导热系数值,分别提高了5.5%、16.4%和27.9%。

英文摘要：

The expansion process and thermal conductivity of expanded graphite expanded with different temperatures and times were studied.The plane heat source method was utilized for the thermal conductivity measurement and the density of the graphite samples was calculated by the measured weight and volume of the samples.The graphite expansion process is good or bad was evaluated by the thermal conductivity of the expanded graphite and the observation of the unexpanded crystal in the expanded graphite,as well as by its density change.The results show that,under every expansion temperature studied,each expanded graphite obtained has its own optimal expansion process.The highest thermal conductivities of the expanded graphite samples expanded at different temperatures and with different expansion times were compared under the condition of having the same density,and the results show that the sample expanded at the temperature of 600℃ for about 10 min has the highest thermal conductivity of 0.09498 W·（m·K）-1 which is 5.5%,16.4% and 27.9% higher than the highest thermal conductivity values of the expanded graphite expanded at 500,700 and 800℃,respectively.