Experimental study of the thermal contact resistance between melting tin and a cold melting pot.

This paper deals with the analysis of the thermal contact conditions during the melting of tin on different cooled wails, for different heat situations and for different cooling flows. TWO experimental set ups are studied. A polished nickel substrate covers the melting-pot of the first one. Semi intrinsic thermocouples are implemented to measure the temperature of the substrate. This will allow a better study of the thermal contact resistance distribution on the wall. The second melting-pot Its surface roughness is variable. The heat system is stronger. The results obtained with the first show that the thermal contact resistance is time-dependent and non-uniformly spread. However, is relatively uniformly spread while the heat power increases. Tests carried out with the second point out huge temperature oscillations which are attributed to unstable thermal contact conditions. This thermal behaviour can be explained by the buckling of the tin crust. The apparition of buckling seems to be favoured by a higher dissipated power and by a higher thermal conductivity of the melting pot.