1. Properties
1. The deposit appearance is similar to chromium deposit. The anti-corrosion and brightness can compare with chromium deposit, the covering ability is superior to standard chromium plating.
2. The energy consumption is lower than that of chromium plating.
3. Suitable for general barrel plating on small parts, production efficiency can increase.
4. The technique is used for light industrial products without special toughness demands. It can get big economic benefit due to being as a substitute for chromium plating.
2. Bath Composition and Operating Condition
Stannous Chloride ( SnCl2.H2O) | 20~30g/L |
Cobalt Chloride ( CoCl2) | 8~12g/L |
Zinc Chloride ( ZnCl2) | 5~10g/L |
Potassium Pyrophosphate ( K4P2O7) | 220~280g/L |
RC-90 Additive | 20~30ml/L |
RC-90 Stabilizer | 4~8g/L |
PH | 8.5~9.5 |
Temp. | 20~45℃ |
Dk | 0.1~2A/dm2 |
Anode | Pure tin plate |
3. Bath Make-up
1. Dissolve calculated volume of Potassium Pyrophosphate (K4P2O7) into 50-60℃ hot water of 1/2 of total volume.
2. Add Stannous Chloride (SnCl2.2H2O) into the above solution slowly, while agitating till it dissolves completely.
3. Add Cobalt chloride (CoCl2) and Zinc chloride (ZnCl2) into tank, while agitating till they dissolve completely, then add water up to the volume.
4. Add 1g/L activated carbon, heat it to 40℃, agitate for 1 hour, rest it for 24 hours, then filter it.
5. Add RC-90 stabilizer.
6. Add RC-90 additive, adjust PH, electrolyze for several hours, then try plating.