Grey scale promoted through laser ablation onto phosphate coated zinc commercial plates

Phosphate coated zinc commercial plates (Anthra-Zinc®) have been processed by laser ablation in the nanosecond pulsed regime varying the repetition rate at 10, 20 and 50 kHz. Phosphate coating was completely characterized. By monitoring the fluence it was possible to define three different processing regimes: phosphate ablation (up to 116 J/cm2), zinc ablation (up to 288 J/cm2) and zinc melting (at 375 J/cm2). 3D profilometry was used to assess both the roughness and depth parameters corresponding to each regime. The brightness was estimated from 450 to 800 nm by reflectance studies. Consequently, a long-lasting grey scale was attained envisaging in- and outdoor decorative uses.