MAO ceramic coatings were prepared on AZ61 magnesium alloy for various processing times ranging from 5 to 60 min, in an electrolyte solution based on silicate-fluoride. The mechanical, electrochemical and, microstructural properties and the phase compositions of the coating layers were investigated. In this work, unlike previous studies, coatings with high amounts of the Mag2SiO4 phase were formed which contained small amounts of MgO and MgF2 at a processing condition of 30 min. A microstructural analysis revealed that the porosity of the coatings was reduced considerably with an increase in the processing time, together with a change in the pore geometry from an irregular to a spherical shape. Potentiodynamic polarization and mechanical testing results showed that the coatings acquired after a processing time of 30 min were superior to all of the others.

Transparent and conducting thin films of Ta-doped SnO2 were fabricated on a glass substrate by a pulse laserdeposition(PLD) method. The structural, optical, and electrical properties of these films were investigated as a function ofdoping level, oxygen partial pressure, substrate temperature, and film thickness. XRD results revealed that all the deposited filmswere polycrystalline and the intensity of the (211) plane of SnO2 decreased with an increase of Ta content. However, theorientation of the films changed from (211) to (110) with an increase in oxygen partial pressure (40 to 100mTorr) and substratetemperature. The crystallinity of the films also increased with the substrate temperature. The electrical resistivity measurementsshowed that the resistivity of the films decreased with an increase in Ta doping, which exhibited the lowest resistivity(ρ~1.1×10−3Ω·cm) for 10wt% Ta-doped SnO2 film, and then increased further. However, the resistivity continuouslydecreased with the oxygen partial pressure and substrate temperature. The optical bandgap of the 10wt% Ta-doped SnO2 filmincreased (3.67 to 3.78eV) with an increase in film thickness from 100-700nm, and the figure of merit revealed an increasingtrend with the film thickness.