Aircraft parts always have a minimum of two (generally three) of deposited layers: a primer, a coat of
paint and a final coat. The maintenance of an aircraft exterior parts need the removal of each layer in a clean, controlled,
precise way, without affecting the substrate material. For surface preparation, the industrial challenge is the quality of the post-stripping surface. If stripping does not leave the surface clean and without damage, an additional finishing step is required. The development and control of stripping would allow gains: In the processing speed, Quality of the treated surface, Precision, Adaptability of the process ( i.e. the ability to remove layer by layer), Reduction of the production of hazardous waste, Cost. Current processes (Chemical, Abrasive, Advanced technologies (laser, FlashJet) does not fill completely actual requirements.
Vulcan project aims to develop an industrial laser shock stripping process able to selectively remove layer by layer the top coat of an aircraft paint stack.
It consists in the production of mechanical shock wave from laser plasma. In playing with laser beams parameters and multi-impacts configurations, we can introduce selectively tensile on interfaces to generate damages if stress level is enough. Without contact, process performed with ns laser pulse allows accurate sollicitation with an accuracy of 1 um in the depth. Stripping products could be recovered in spalls of layers. Process parameters are optimized using numerical simulation and material stack properties.
The VULCAN project objective is to go beyond traditional stripping using laser shock in order to fulfill all requirement of aerospace industry that are:
-Development of a dry stripping process Environmental friendliness (no use of chemicals and liquid solutions, reduction of production of hazardous wastes, no water consumption, limited worker exposure to toxic and hazardous substances, reduction of hazardous material disposal costs)
-Universal solution that can be applied on metallic and composite substrates
-Selective = controlled stripping of a thin layer without affecting the surface treatment or the prime, For metals = corrosion protection stays intact, for composites = no top coat or fibers damages No deformation or any kind of damage
-Automated for productivity benefits (cost effective, reproducibility, efficient speed)
