Data from: Quantification and mitigation of uncertainties in thermal conductivity measurements using a modified ASTM D5470 thermal resistance tester

In this paper, we have investigated the effect of thermal interface
materials (TIMs) on the accuracy and uncertainty of thermal conductivity
measurements. A modified ASTM D5470 thermal resistance tester (TRT) has
been developed to measure the out-of-plane thermal conductivity of
pyrolytic graphite (PG) and titanium grade 2 (TiG2) with and without TIMs.
Compared to the ASTM D5470 standard, this modified design uses three
thermocouples per side to support regressive analysis of the temperature
profile and quantifies the uncertainty of the measurements with and
without TIMs. Nine PG samples and four TiG2 samples of varying thickness
have been tested to obtain thermal resistance as a function of sample
thickness. The steady-state temperature profiles were used for heat flux
and thermal resistance calculation. The results reveal that TIMs
significantly reduce measurement uncertainty for both samples, i.e., 38.8%
for TiG2 and 27.8% for PG. The effect of TIMs on the measurement accuracy
diverges, with a far more pronounced effect on TiG2 than PG. This can be
owed to the higher out-of-plane thermal conductivity of TiG2 (~ 16.2
W/m-K) than PG (~ 2 W/m-K). Contact resistance is expected to play a more
critical role in tests of materials with higher thermal conductivity, and
TIMs can effectively mitigate contact resistance. For lower conductivity
materials, the weight of contact resistance is lower, and the effect of
TIMs is thus less pronounced.