Laser surface texturing pre-treatment before thermal spraying – a way to adapt and control the surface topography to the considered materials and the stresses imposed

 

Coating characteristics are very dependent on the substrate preparation and spray parameters. That’s why the surface must be adapted mechanically and physico-chemically to favor coating substrate adhesion.  Conventional method as Grit-Blasting is limited as a surface preparation and produces large plastic deformations throughout the surface resulting compressive stresses. Laser surface texturing promotes coating/substrate adhesion and are suitable to prepare the surface of sensitive material. The use of these techniques, which leads to several benefits such as surfaces free of grit-particle inclusions, directly improves the quality of coatings and their life span. Laser Surface Texturing adapts impacted surface by particles to create anchoring areas.

The essential idea here is to compare adhesion for two surface preparation methods Grit-Blasting and Laser Surface Texturing for two couples used in aeronautic: Ni-Al / Al2017 and ZrO₂-Y₂O₃ / AM1. Optimized surface topographies can then be designed according to the materials as well as their applications.