Where the world gathers for
plating, anodizing, & finishing Q&As since 1989




-----

Corrosion resistance properties of electroless nickel plating

 

I have recently started EN plating for some valve industry. I would like to know the process of knowing the phosphorous content in the plating done because it plays very important role in corrosion resistance properties. Is there some test by which I could come to know whether the plated component is corrosion resistance? Is there something called as rca test?or nitric acid test? please let me know the reference to this.

Vikram Patel
- Pune, Maharashtra, India

---

 

Use an atomic absorption spectrophotometer, or an ICP. Both will measure phosphorous but you will need to dilute.

Bill Berilco
- Simcoe, Ont., Canada

---

 

Dear Vikram ;

To know the corrosion resistance of your ENPlated job.. Yes..here are my inputs:

SALT SPRAY TEST as per ASTM B733 [affil link] standard for more than 12microns(0.5mil)...and the hrs of salt spray to be specified by the customer...depending on the base metal and the plating thickness reqd...

NITRIC ACID DIP TEST for less than 7 microns thickness in EN plating.

FERROXYL TEST (POROSITY TEST)
25gm of potassium ferricyanide+15gm of sodium chloride...to be mixed in 1 litre distilled water..(the mixture can be varied in proportion based on reqmt) the part to be tested...should be thoroughly cleaned and then dipped in this solution(ferroxyl)...for 30seconds... take the part, clean again in running water...

and observe the part for blue spot deposition.. (
THIS TEST IS PREFERRED FOR MORE THAN 15MICRONS THICKNESS EN PLATING and NOT PREFERRED FOR ROUGH CASTING PARTS) BOILING WATER TEST (FOR POROSITY).

Vijayakanth
WeP Peripherals Ltd - Mysore, Karnataka, INDIA