To answer current issues adequately considering technical, economic, as well as environmental requirements, material transformation and especially surface treatment industries must be source of innovations to be proactive. As a result, developing new alternative solutions to existing ones had become a top priority. Considering surface treatment processes, conventional ones (thermal spraying, plasma transferred arc) do not allow to consider this approach since the processes themselves (co-treatment of different powders) do not permit to guarantee the initial composition nor do they ensure a sufficient homogeneity to the coating structure. If indeed the dry surface treatment processes have already shown large potential, several limits remain such as an inefficient adhesion, an environmental impact over the life cycle or almost no materials on the market. To overcome these issues hybrid coating technologies (combining several processes) are likely to be developed. From all of them, laser technology seems to be very promising due to its high flexibility considering all the potential parameters (varying power, continuous or pulsed beam, etc.) and the localised treated area. For instance, combining simultaneously a laser with a thermal spray process enables the elaboration of a thick coating showing a good adherence. The ablation laser applied on the substrate surface just before the impacting particles as promoted in the PROTAL process permit to insure a suitable surface state favourable to the particles adhesion. The control of the coating microstructure was not so much studied. That is why, to complete the knowledge in this area, this work aims at studying the influence of laser technology in association with plasma spraying on the coating microstructure and more precisely on the coating mechanical properties. Coatings were characterized by SEM and void content was evaluated through image analysis and Archimedean porosimetry. Mechanical properties were assessed by the four points bending test for evaluating the coating apparent Young modulus.

Solid oxide fuel cell are being widely considered as the promising answer to the fossil energy decrease. To achieve high efficiency and longevity for SOFC stack it is essential to maintain stable hermetic sealing. In order to obtain an efficient airtightness between two SOFC layers, the authors had developed a solid seal composed with a ceramic matrix charged with glass particles. The seal is plasma-sprayed using low-cost manufacturing methods such as atmospheric plasma spraying. This technical deposit can be plasma-sprayed on a wide range of substrates: whatever its nature and shape. It is solid, distortable and adhesive to its support at ambient temperature. The sealing properties are acquired when the SOFC is put into service: the glassy phase migrates into the peculiar plasma-sprayed microstructure of the ceramic matrix towards the interface involving the airtightness. The performance of this seal are pretty good: the leak rate observed at 70 mbar is 0.0042 mbar.l/s whereas the preconisation of the US Department of Energy is 0.005 mbar.l/s.