Interfacial and bulk thermal conductivity fromdynamic temperature profiles on one side of

摘要

Reliable and rapid measurement of thermal conductivity (k) is one of the mostimportant current industrial requirements. This experimental, theoretical and modellingstudy examines the validity of measurements from probes that apply momentary heat onone side of the sample and infer the thermal conductivity from the temperature responseobtained through assumed heat transfer models. It is shown that there is a criticalsample thickness below which the inferred values will be compromised by the materialabove the sample. With sufficient sample thickness, the measurement obtained is stillinfluenced by interfacial resistances present (e.g. Sensor to sample) and these should beremoved with the help of contact agents (Cas). We show how the dynamic temperatureresponses at the sensor surface (and hence the inferential capacity of the technique) areinfluenced by critical system parameters through one dimensional dynamic heat transfermodels. Separate FEM models helped in establishing the extent of validity of the onedimensional assumption. Experimental data on selected cases with and without contactwith metallic weights show how the critical thickness required increases with samplethermal conductivity. The measurements with and without weight converge towardseach other and then remain steady with further increase in sample thickness.