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High Speed Additives For Chromium Electroplating

2000

Dear Sir,

we have been doing Hard chrome plating for Piston Rods of Hydraulic cylinders. As we are new to this field, we have been using conventional bath.We come to know that by adding some "ADDITIVES" or "CATALYSTS" we can speed up the existing plating process.Right now we are getting a plating speed of 1 µm thickness /3 Minutes. Now we would like to increase the speed of the process by adding the "ADDITIVES". Right now we are using the following parameters: Bath Composition:

1.Chromic acid Concentration = 200---230 grms/lit.
2.sulfuric acid Concentration = 2---2.5 grms/lit.
3.Ratio Between Chromic Acid and sulfuric Acid = 100:1
4.Volts = 6 Volts.
5.Current = 30 amps/dm.
6.Distance Between Anode and Cathode = 4".
7.Bath Temperature = 55 °C (Plus or Minus 5 °C).
  Anodes Composition:
 
1.Lead ----98%.
2.Tin------2%.
  Analytical Data Of Chromic Acid that we are using:
  Chromium Trioxide as CrO3 (%)...99.00 Sulphate as SO4 (%)...0.20 Alkali Salts as Na2O (%)...0.30 Chlorides as CI (%)...0.05 Matter Insoluble in water (%)...0.15  

I Would be Grateful, if you could help me, by Sending the details of the "ADDITIVES", that will Speed up my Plating processes. So that I can try out on some Experimental Bath. Thanking You,

Your's Sincerely

P.SUDHEER BABU
- Bangalore, India

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There are partially-soluble fluosilicate addition agents that may speed up the plating, and there are newer proprietary systems as well. But we'd like people to refer you to books which contain such formulas rather than printing the formulations here--surely you are aware that the suppliers of proprietary high speed baths have spent fortunes developing such additives, and they are very valuable trade secrets.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2000

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Dear sirs:

Hello,we follow the electroplating process to a nickel plate approx.{55 * 73 cm} just for making a protective layer of chromium, in order to protect the plate while printing,we have used the same condition applied by the indian person who asked the question, but we are suffering from the plae chromium layer. In addition to CrO3, there is an other component in the bath about 5% of trivalent chromium as Cr2O3, and in the process first usually we apply flashing, i-e increase the amperes 1000 more than the request just for 18 sec.

Would you please advice to avoid this problem.

Adil Elhag Ahmed
- Sudan
2001