Measurement of thermal diffusivity/thermal contact resistance using laser photothermal method at cryogenic temperatures

The Laser Photothermal Method (LPM), which is a transient non-contact technique, was employed to measure the thermal physical parameters of Stainless Steel 304 (SS304), Oxygen-Free Copper (OFC) and Aluminum Nitride (AlN) ceramics. The thermal diffusivity of SS304, OFC and AlN ceramic were measured by the LPM and some explanations for the tendency with the temperature were given. Compared with the reference values, it showed that the LPM is reliable in measuring thermal parameters. Following, the Thermal Contact Resistances (TCRs) of OFC-AlN ceramic, SS304-AlN, SS304-SS304 and AlN ceramic were measured in the temperature range from 70 K to 300 K and the contact pressure was on the order of 0.10 MPa. Some explanations were given to make clear the changing trend of TCRs with the increase of temperature. Moreover, some empirical formulas of the TCRs were established. The accuracy of the establishing empirical formulas had been validated by the experiment, and the error was smaller than 9%.