Influencing factors of thermal contact conductance between TC4/30CrMnSi interfaces

Thermal contact conductance (TCC) between interfaces is an important parameter in the analysis of temperature field for structural components. Of great concern is the TCC between TC4/30CrMnSi interfaces, as TC4 and 30CrMnSi are the main structural materials used in aviation engines. This paper presents an experimental study of influencing factors of TCC. The effects of temperature, applied load, heat flux direction and surface roughness on TCC using a test device independently developed are detailed. The temperature of contacting surfaces ranges from 200 °C to 350 °C, and the pressure of consideration is from 0 MPa to 150 MPa. Results show that the temperature affects little on TCC. TCC reaches its peak value at approximately 120 MPa in the processes of loading and unloading, but the variation trends are found to be different for the two processes. Compared with smooth surfaces, the rough surfaces exhibit higher TCC values under the same condition.