Activation of Passive Nickel for Deposit Stress Analyzer Tests
Depending on the chemistry of the plating solution selected for internal deposit stress determination, it may be necessary to activate the surface of PN: 270 NI test strips to obtain adhesion of the applied metallic deposit. While a Wood’s nickel strike could be used to solve this problem the directions are found in option 2 however, a more simple way is to dip the test strip area to be plated in the solution found in option 1at room temperature for 10-30 seconds. If option 1 doesn’t work you will need to use option 2.
Two options for activating the pure nickel PN: 270NI test strips:
1-Simple dip solution:
Add to one gallon of water the following chemicals:
3 Fluid ounces of concentrated sulfuric acid slowly with stirring.
One third ounce of Potassium Iodide.
0.002 Ounce = 0.062 Grams of solid Iodine.
The Potassium Iodide is dissolved in a separate small amount of water and the solid iodine is added. When the iodine has dissolved the solution is added to the cold diluted sulfuric acid solutions and thoroughly mixed. In use, the iodine should be added periodically to maintain a straw color.
Follow this surface treatment with a water rinse and proceed with plating the test strip.
2-Wood’s Nickel Strike:
Nickel Chloride 38 oz/gal. (1,077 grams/ gal.)
Pure Hydrochloric Acid 14 fluid ounces/gal. (325 ml/gal.)
Treat the 270NI test strip in the nickel strike with positive anodic current at 30 ASF (0.25 amp) for 30 seconds, then with negative current for 45 seconds at 30 ASF. Water rinse and submit the test strip to the plating bath sample for the internal deposit stress evaluation. Note that this treatment has little impact on the final deposit weight, but for critical situations, it is the best practice to rinse, dry and weigh the test strip prior to submitting it to the plating test.