Experimental Study of Filler Insertion Effect on Mean Thermal Contact Conductance

Abstract

A series of experiments have been performed to investigate the filler insertion effect on the temperature drop at the wavy contact interface ΔT and the mean thermal contact conductance h_{m, f}. Representative behavior of ΔT against the mean nominal contact pressure p_m is clarified, and the effect of an interval of time on ΔT is shown for the silicone filler with thickness δ_fo=2mm. The silicone elastomer is proved effective to increase h_{m, f} despite its low thermal conductivity. Further, it is shown that h_{m, f} of 0.5mm thick silicone filler becomes two to three times higher than that of bare contact under the unloading process. However, it is also shown that h_{m, f} decreases with increasing δ_fo, therefore filler insertion with improper thickness results in a reverse effect on increase in h_{m, f}. As for metallic filler insertion using an aluminum or a copper foil, only a little improvement in h_{m, f} is obtained in spite of its high thermal conductivity.