Blue and Green Phosphate Coatings Formed on Steel Without Heating

Phosphate coatings were obtained by cold method from solutions based on Mazev Salt (containing Mn(H 2 PO 4 ) 2 •2H 2 O and iron phosphates).Metal nitrates and nitrites were introduced into solutions as accelerators of the phosphating process.To obtain green and blue phosphate coatings, procyon olive green and methylene blue dyes (8 g/L) were added into the solutions.Colored phosphate coatings are deposited unevenly on the steel surface.The thickness of the modified phosphate films was estimated from SEM images of the cross-section samples and determined to be 3-4 microns.Colored phosphate coatings are fine-grained with a grain size of 170-190 nm, which was determined using an atomic force microscope.Phosphate films continue to exhibit protective properties when heated to 100 • C. With a further increase in temperature, the protective ability of the film is significantly reduced.Colored phosphate films have a low coefficient of friction (0.1-0.15).The breakdown voltage of colored phosphate coatings is 180-200 V, which characterizes low electrical insulation ability.Based on the established properties, colored phosphate coatings can be used as protective and decorative.