THE THERMAL CONTACT RESISTANCE OF TWO INTERFACES AT LOW TEMPERATURE IN VACUUM

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.