NEWS

Wenbo electroplating equipment's black nickel plating post-treatment to improve the discoloration resistance

2021-5-28 10:08:07

Linyi Wenbo electroplating equipment has learned from practice for many years that the black nickel coating has good matting properties, so it is widely used in optical instruments, aviation, electronics and military production. The black nickel coating is actually a Zn-Ni alloy layer, which is relatively hard, has poor corrosion resistance, poor wear resistance, and is easily oxidized and discolored. Therefore, the parts after the black nickel plating must be immersed in oil or coated with protective varnish. During the production process, products or parts plated with black nickel will quickly change color and become blurred if they are not properly post-treated. Therefore, post-treatment is a very important part.

After the black nickel coating is post-treated, the discoloration resistance is greatly improved. The author has made passivation or chemical treatment on the black nickel coating in CrO3K2O7, Na2Cr2O7, Na2CO3 and other solutions. The experimental treatment has the best discoloration prevention effect and low cost. .

The black nickel-plated product is a combination of brass and iron, and the electroplating process is: copper cyanide (2min) ---acid copper (8min) - bright nickel (5min) - black nickel (1min).

After the black nickel-plated parts are passivated in CrO3 passivation solution for 20 seconds, they are placed on the mouth of a plastic bucket containing 20L HCl, and the acid mist is smoked for 10 seconds, and then the degree of discoloration of the appearance is observed.

After experiments and considerations of economy and environmental protection, the black nickel coating is passivated in the following passivation solution with good results.

CrO32.5g/LpH1.5-5 (2.5g/LcrO3's natural pH) t10-20s temperature 10--30℃.

After testing, the passivation solution can be used for anti-tarnish treatment of coatings such as gun-colored nickel and black pearl nickel in addition to black nickel.

Linyi Wenbo Electroplating Equipment--Specializing in the production of electroplating equipment, electroplating equipment, high-frequency pulse electroplating power supply, SCR electrolytic aluminum oxide coloring, electrophoresis, brush plating, AC iron plating cycle, power supply, and various specifications of rectifier equipment, barrel plating tank, string barrel filter, etc. Electroplating equipment such as spin dryers, Tel: 0539-8631996. The company is close to the beautiful Yihe River, west of the Beijing-Shanghai Expressway, and 205 National Highway passes by the door. The transportation is very convenient.