Direct laser synthesis of functional coatings by FEL treatments
Smart surfaces and functional coatings play a decisive role for applicability and performance of all modern materials. Many methods have been developed for their fabrication. Recently, it was established that short laser pulses can induce a direct laser synthesis of functional coatings if the material's surface is irradiated in reactive atmosphere. De-spite the simplicity of the treatment itself, the process is not yet industrially established, maybe due to the lack of high repetition rate high power pulsed lasers enabling fast and easy treatment of large areas and pieces. The Free Electron Laser (FEL) can be just the right tool to drive this process into applicability. The high power and the flexibility in temporal shaping of the FEL at the Jefferson Lab made it very interesting for direct laser synthesis of functional coatings. The produced coatings were investigated by a number or methods and the obtained results are presented in connection with the FEL treatment parameters. TiN coatings of about 15 mm thickness could be easily produced. Furthermore, (100) texturing of the TiN was found for certain timings of the FEL, which is explained by temperature and solidification modeling during the FEL irradiation.