Values are generally needed for thermal conductivity, expansivity and modulus. These are quite a challenge to measure because the nanoceramic only exists as a thin film attached to a thick aluminium plate.
Thus far we have not been able to obtain a value for the CTE since, when attached to the aluminium, it is totally dominated by the metal. The unconstrained surface expansivity is 22ppm/k. For the film
itself, a value of 8ppm/k is probably a good a guess as any. Initial results, which are likely to be revised, are that the elastic modulus is in the region of 210GPa (+/-60GPa) with around 20-25% elastic recovery
(Nano indentation method). The thermal conductivity is 7.3 W/mK (laser flash method) and isotropic; this figure was derived by back-calculation and therefore includes the thermal interface resistance between
the nanoceramic and base aluminium. Typical nanoceramic thickness is 22+/-1um (eddy current method – by SEM its better expressed as 22um with Ra 0.7um, Rz 3-4um).