DEVECO ACID ZN/CO PLATING

Deveco Acid Zinc Cobalt plating system offers a zinc alloy containing 0.1% - 0.9% (by weight) cobalt. This system provides a bright, ductile deposit with excellent corrosion protection properties. Deveco specified conversion coatings (ea. chromates) should be used for maximum corrosion protection.

OPERATING PARAMETERS:

Barrel Operation:

pH 5.0 – 6.2

Zinc 2.5 – 4.5 oz/gal

Potassium Chloride 15.0 – 20.0 oz/gal

Ammonium Chloride 5.0 – 8.0 oz/gal

Zn/Co Brightener based on Amperage & Dragout Make-up: 1.0%

Zn/Co Wetter 3.0 – 6.0 oz/gal

Cobalt 0.2 – 0.5 grams/liter

Rack Operation:

pH 5.0 – 6.2

Zinc 3.0 – 5.0 oz/gal

Potassium Chloride 15.0 – 20.0 oz/gal

Ammonium Chloride 5.0 – 8.0 oz/gal

Zn/Co Brightener based on Amperage Make-up: 1.0%

Zn/Co Wetter 3.0 – 6.0 oz/gal

Cobalt 0.1 – 0.4 oz/gal

CONDITONS OF OPERATION:

Temperature 70 - 110°F

Current Density 1 – 80 amps/sq ft

Anode Area 1:1 minimum anode to cathode

MAINTENANCE OF SOLUTION:

Zinc Analysis

Cobalt Analysis

Potassium Chloride Analysis

Zn/Co Brightener Amp Hour or Hull Cell

Amp Hour = 1 gallon of Zn/Co Brightener per 20,000 – 30,000 amp hours

Zn/Co Wetter By dragout

MAKE-UP PER 100 GALLONS:

1. Use lined steel tank leached with 5% HCl for 24 hours

2. 50 gallons warm water 110 - 120°F

3. 6.25 gallons concentrated ZnCl solution

4. 112.5 lbs Potassium Chloride

5. 37.5 lbs Ammonium Chloride

6. .6 lbs or 266 grams Cobalt Chloride

7. Adjust pH to 5.5

DEVECO ACID ZN/CO PLATING

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RECOMMENDED PROCESS CYCLE:

1. Soak Clean

2. Thorough water rinse

3. Anodic clean (12 volt rectifier)

4. Cold water rinse

5. Hydrochloric Acid 50% plus Deveco Inhibitor K-1 5%

6. Thorough water rinse

7. Zn/Co Process

8. Thorough water rinse

9. Sour rinse—nitric acid—1/2 oz/gal

10. Chromate dip

11. Cold water rinse

12. Warm water rinse

13. Dry

ANALYTICAL PROCEDURES:

Zinc Analysis (Non-Formaldehyde Method)

Reagents:

1. Acetate Buffer D.S.

To make up, dissolve:

a) 180 grams of Sodium Acetate

b) 30 ml of Acetic Acid

c) Add D.I. or Distilled Water to make 1 liter

2. Xylenol Orange Indicator

To make this indicator liquid:

a) One gram of Xylenol Orange

b) Dissolved in 1 liter of D.I. or Distilled Water

3. 0.1M Disodium EDTA Solution

Procedure:

1. Into a 400 ml beaker pipet a 5ml bath sample.

2. Add 150 ml Distilled or D.I. water.

3. Add 50 ml Acetate Buffer D.S.

4. Add sufficient Xylenol Orange Indicator (~0.5 ml) to give a fuchsia color (bright reddish pink)

5. Titrate with 0.1M Disodium EDTA solution until the color changes (fuchsia Þ yellow). This changes very rapidly; proceed very slowly. In some baths an orange color will occur seconds before the yellow.

6. Calculation: ml of titration x 0.176 per ml = Total metal in oz/gal

ml of titration x 1.32 per ml = Total metal in g/l

7. Total Metal in oz/gal – Co in oz/gal = Zinc in oz/gal

Total Metal in g/l – Co in g/l = Zinc in g/l

Analysis for Cobalt in the Bath:

Check the Cobalt in the bath on the Atomic Absorption unit. Use the procedure

as provided by your AA supplier.

Analysis for Chloride in the Bath:

1. Pipette a 1 ml sample of the plating bath into and Erlenmeyer flask.

2. Add about 5 ml of 10% Sodium Chromate to give the solution a yellow color.

3. Add 75 – 100 ml of distilled water.

4. Titrate with 0.1N Silver Nitrate until permanent reddish brown color forms on a white chloride.

Calculation: Oz/gal of Cl = 0.473 x mls of Silver Nitrate.

DEVECO ACID ZN/CO PLATING

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To increase composite Cl 1 oz/gal add 12.5 lbs. Potassium Chloride (KCl) per 100 gallons of plating bath.

Analysis for Ammonium Chloride in the Bath:

Hach Color Wheel Method: Ni-8 color wheel and Nessler Reagent, both available from Hach Corp.

Read Material Safety Data Sheet before using this product.

DISCLAIMER:

The information presented herein, while not guaranteed, is to the best of our knowledge true and accurate. No warranty or guarantee expressed or implied is made regarding the performance of any products, since the manner of use is beyond our control. No suggestion for product use or anything contained herein shall be construed as recommendation for its use in infringement of any existing patent and we assume no responsibility or liability for operations which do infringe any such patents. The above includes confidential and proprietary information of Deveco Corporation and is furnished to you for your use solely on products or processes supplied by us to you.