Reduction of classical thermal conductivity under the influence of high‐power lasers
Observation of the front and rear plasma expansions from a laser‐irradiated thin film has been used to study the thermal conduction of polystyrene targets. The existence of reduced conductivity has been inferred above a threshold of 1014 W/cm2. The percentage of laser radiation transmitted through the thin film decreased by an order of magnitude as the laser flux increased from 1013 to 1014 W/cm2.
AbstractThe present paper reports on the production of oxide coatings on an aluminium alloy by microplasma oxidation and on their properties. The surface characteristics of the coatings were determined by surface and structural analytical techniques, i.e. SEM and X-ray diffraction. Thermo-analysis of the coatings was evaluated by means of differential scanning calorimetry and thermogravimetric analyses. It was ascertained that the coatings with a mixture of crystallised γ-Al2O3 and α-Al2O3 have significant microhardness, good electric resistance and good thermostability.