The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Brown Foreign Material on stamped parts

2007

I'm having an issue with a stamped part. The part is exhibiting a brown/dark brown FM on the sides and bottom. It appears on both the gold and alloy42 surfaces. SEM shows higher concentrations of oxygen, carbon, sodium, potassium, and chlorine in the FM areas. See the below picture:


The part is alloy 42 (ni-fe) cladded with gold. The parts are treated with vanishing oil for stamping and cleaned in a trichlorylethylene solution. The TCE is closed-loop, filtered by 5 and 1 micron filters, and continuously distilled.

Many other material types are cleaned using the same cleaner - could this be causing the foreign material.

Andy Hendricks
Assembler - Minneapolis, Minnesota

---

2007

Hi Andy,

You are using a few abbreviations which I don't quite grasp.
What are your Ni and Au plating thickness?
You see this after your plating process?

Jen Teh
- Penang, Malaysia

The material is cladded, not plated. Gold thickness is roughly 100-200 micron. The rest is alloy 42 (ni-fe)

Andy Hendricks
- Minneapolis Minnesota
2007