plating, anodizing, & finishing Q&As since 1989
Brass strip material corrodes and fractures after tin plating
Small electrical connector terminals of brass wire are flashed with 2.5 microns of nickel then receive 2.5 microns of tin plating. Some terminals found in inventory show severe corrosion. These terminals exhibit brittleness and fracture easily when bent.
The root cause for the corrosion and brittleness has not been identified. However, the plating supplier has offered that some terminals are "sticking" in the tub after cleaning.
Response from anyone having a similar experience will be appreciated. I am investigating root cause of this type of failure.
Please confirm if the part is strip or wire. Either way you need to anneal the parts at 200 degrees C for an hour before plating to avoid this. Also look into putting in a stress reducer into the nickel plating.
Bengaluru, Karnataka, India
My opinion is:
1. the plater use HCl but not H2SO4 in the pretreatment
2. inadequate current density used.
May be the nickel layer in not adequate to stop migration of Zinc from brass to reach to surface. Has the surface become blackish?
You are experiencing galvanic corrosion reaction between the nickel plate and brass interface. Alkaline or cyanide copper plate the brass, then nickel plate should help you.Hamilton Solidum
Q, A, or Comment on THIS thread -or- Start a NEW Thread