757 Tin-cobalt gun black color plating process
★Use and characteristics
1.The cobalt content in the plating solution is four times higher than that of the micro -cobalt, and the plating solution is adapted to the production of large batch, and the appearance of the coating is dark and beautiful.
2. Low cost,
3. Fast plating, good location, very simple and easy operation.
4.Barrel plating time is short, low carbon and no irritating odor.
★Solution composition and operating conditions
1.makeup method :
Add a small amount of hot water dissolved 10g cobalt chloride in tank, adding 480ml assistant agent , 40 ml of blackening agent, add 16g blacken salt which has dissolved in water and black stannous salt 4 grams, add 2 ml of wetting agent and predetermined volume of water, stirring to dissolve blue purple transparent solution. Adjust PH in between 12 - 10, heating up to 40 degrees Celsius, then electrolytic and test.
1000AH consumption, Zinc alloy jewelry as an example: the black agent 1kg, assistant agent 3 kg.
2.Operation condition:
Cobalt chloride 13 g/L( cobalt containing 3.25 g/L), stannous salt 4 g/L(tin containing 2.3 g/L), usually control the proportion: Tin :cobalt =1:1.5-2 or stannous salt: cobalt chloride solution =1:3-4, the plating bath proportion is 23-28 baum (best Be 25), PH (10-12 wide strip) temperature 35-45 (best 40 C), anode graphite plate, cathode current density 0.2-1.5A/dm,2 3-4 V plating voltage, PH adjustment, High with dilute potassium hydroxide solution, reduced with dilute hydrochloric acid solution, must filter.
3.product catalog : The assistant agent, blacken agent, black salt wetting agent.