Surface preparation via grit-blasting for thermal spraying

The major reason for grit blasting for thermal spray applications is to ensure a strong mechanical bond between the substrate and the coating by the enhanced roughening of the substrate material. This study presents five statistically designed experiments that were accomplished to investigate the grit blasting process. The experiments were conducted using a Box statistical design of experiment (SDE) approach. A substantial range of grit blasting parameters and their effect on the resultant substrate roughness were investigated, including grit type, pressure, working distance, and exposure time. The substrates were characterized for surface characteristics using image analysis. These attributes are correlated with the changes in operating parameters. Optimized process parameters for the two machines used in this study as predicted by the SDE analysis are presented.