真空低温环境导热填料界面接触热阻实验研究
THE THERMAL CONTACT RESISTANCE OF TWO INTERFACES AT LOW TEMPERATURE IN VACUUM
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摘要: 真空低温环境下，接触热阻对热传递有十分重要的影响。根据接触热阻产生机理和实验测试原理，建了一套真空低温环境下固体界面接触热阻测试的实验装置。实验对比研究了不同温度和不同预紧力条件下，固体界面裸接与在界面之间添加真空硅脂、铟膜、石墨烯、石墨片导热填料时的接触热阻。实验结果表明，接触界面的接触热阻都随温度升高和预紧力增大而减小。在接触界面添加真空硅脂或铟膜后接触热阻随预紧力变化非常，裸接或添加石墨烯的接触热阻随预紧力变化较大，但是当预紧力大于2.5 N·m时其接触热阻基本不变。温度越低时添加导热填料减小接触热阻的效果越明显。总之在两界面之间添加铟膜时效果最佳，此时接触热阻随预紧力和温度的变化都较小，此种情况下接触热阻最小可以达到3.5×10-6K·m2/W。Abstract: The thermal contact resistance has a big effect on the heat transfer at low temperature in vacuum.According to the mechanism of production and principle of experimental test of thermal contact resistance，the test system is built which could test the thermal contact resistance at low temperature in vacuum.Study the thermal contact resistance between two contact surfaces with different fillers such as indium foils，vacuum grease，graphene and graphite flake at different temperature and pretightening force.The result indicates that thermal contact resistance decrease with the increase of temperature and pretightening force.The thermal contact resistance almost not change with the bolt pretension when adding indium foils or vacuum grease，however the thermal contact resistance changes greatly with the bolt pretension when adding graphene or nothing.But the thermal contact resistance almost not change when the bolt pretension is bigger than 2.5 N·m.Adding thermal conductance fillers could decrease the thermal contact resistance effectively，especially at low temperature.The indium foils show the best performance to decrease the thermal contact resistance and minimum thermal contact resistance is 3.5×10-6K·m2/W.
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