Thermal Contact Conductances of Metallic Contacts at Low Loads

Experimental investigations on thermal contact conductances of metallic contacts have been reported here. The studies are restricted to relatively low contact pressure: hardness ratios $(< 0.7 \times 10^{-3})$ where very little data exist. These results have applications in situations like some types of electrical contacts, cooling of electronic components, contacts in instruments and highpower semiconductors. Results show that the behaviour is considerably different from what happens in high-pressure contacts, due to the increased importance of gap fluid conductance at low pressures. This is not the case at higher interface pressures where the dominant mechanism is the solid spot conductance. The study shows that the correlations developed for highpressure cases cannot be used for low-load conditions. The effects of mean interface temperature, interstitial fluid and thermal rectification are also found to be more pronounced than those for high-pressure conditions