An experimental investigation of thermal contact conductance of stainless steel at low temperatures

An investigation is carried out to study the effects of surface topography and interfacial temperature on the thermal contact conductance of the pressed stainless steel 304 contacts in the range 125-210 K and 1-7 MPa. The surface roughness of test specimens is between 1.5 μm and 17.6 μm. A theoretical model is used to predict the results and gives a reasonable agreement. The combined effect of phonon conductivity and electronic conductivity to thermal conductivity at low temperatures is described using a proposed correlation. The small contact conductance at low temperatures can ascribe to the decreased thermal conductivity and the increased hardness. It is demonstrated that rms roughness and mean absolute slope are both needed for evaluating contact heat transfer.