Method for electroplating double-layer admiro film on Nd-Fe-B magnetic surface

[0034] After electroplating double-layer zinc-nickel alloy by embodiment one process, dark green passivation: chromic anhydride 40g / L, phosphoric acid 10mL / L, nitric acid 3mL / L, sulfuric acid 5mL / L, hydrochloric acid 5mL / L, zinc ion 1.Sg / L L, pH ~ 2, soak in the solution for 3 minutes, stay in the air for 15 seconds, wash with water after passivation, and age at 60°C.

[0035] The coating is bright, dark green, with good bonding force, and there is no white rust after 360 hours of neutral salt spray corrosion.

[0036] Carry out pre-plating treatment according to Example 1, zinc sulfate 250g / L, nickel sulfate 50g / L, boric acid 30g / L, brightener 20mL / L, pH value 4, temperature 20 ℃, cathode current density 8A / dm 2 Galvanized nickel alloy for 20 minutes; zinc chloride 100g / L, nickel chloride 80g / L, ammonium chloride 200g / L, brightener B 15mL / L, pH 3.5, temperature 30°C, current density 2.5A / dm 2 Electroplating zinc-nickel alloy for 30 minutes. ;Chromic anhydride 20g / L, titanium ion 5g / L, sulfuric acid 4mL / L, sodium fluoride 3g / L, 50~55℃, soak in the solution for 10~15 seconds, stay in the air for 5~10 seconds, after passivation Wash with water and air dry.

[0037] The coating is bright, iridescent, and has good bonding force, and there is no white rust after 240 hours of neutral salt spray corrosion.