Abstract
- Laser surface texturing has been established as an efficient and appreciated method to control and tailor surface functionalities further providing great potential for innovations in modern surface engineering. This is investigated in the presented study for replacing grit blasting technologies by high-rate laser texturing in coating substrate preparation with goal to enhance adhesion and reliability of coated components as well as reducing dust generation and grit material usage. On metallic and ceramic materials, different surface textures, such as dimples, trenches and pillars, were produced by employing up to 3 kW laser powers delivered by continuous-wave fiber lasers as well as nanosecond and femtosecond lasers in combination with polygon mirror based scanner for high-speed surface processing. The laser beam raster scanning at several hundred meters per second is in particular beneficial to reduce thermal loads and stresses to the substrates at these high laser powers avoiding cracking of substrate and coated layers. This was verified by IR thermal monitoring of heat accumulation during the laser process in nanosecond time resolution. Another benefit is the achievement of unprecedented high processing rates ranging up to 300 cm²/min, verifying laser based surface texturing as competitive method compared to grid blasting in coating substrate preparation.