-- The Home Page of the Finishing Industry

on this site
current topics
Live! From beautiful Pine Beach New Jersey: Welcome to the world's most popular metal finishing website

topic 32177

Blisters of sulphamate nickel plating after sintering


We plate a copper flange with Sulphamate Nickel ( 70-100 microinch) and sinter it in dry hydrogen at 800 degree C. I am getting roughness ( small blisters) on the surface after sintering in Hydrogen. We use a local plater for this process and getting inconsistent results from batch to batch. We supply the copper after annealing at 875 degree C. Is there anything I can do with sintering or annealing temperature to correct this or should I look for another plater?

Sara Mathew
- San Jose, California, USA

First of three simultaneous responses -- 2004

I am a little confused. Does your term "sinter" mean that you apply the heat and pressure after plating on a solid substrate, and if so, why? Or is it that you produce the copper flange by powder metallurgy and then sinter the part again after it was plated?

Guillermo Marrufo
Monterrey, NL, Mexico

Second of three simultaneous responses -- 2004

One likely cause is caused by insufficient cleaning prior to annealing. Baked-on surface contaminants are very difficult to remove. Be sure to thoroughly clean the copper before annealing. Another possible cause is insufficient cleaning by the plater prior to plating. Another is hydrogen entrapment. To solve this one, bake at a low temperature, 275 F for about 1 hour to remove hydrogen before sintering.

don baudrand
Don Baudrand
Consultant - Poulsbo, Washington

(Don is co-author of the
book "Plating on Plastics")

Third of three simultaneous responses -- 2004

The problem is that the part is not completely clean. There is also a remote possibility that it has been over etched.

The plater could probably experiment with other cleaning or etching solutions to find something that will work better.

You can help by providing an annealed part that has less oxidation. This means a clean vacuum furnace or a reducing atmosphere furnace with an inert gas cool down for both.

875C seems like a high temp for an anneal cycle on copper.

James Watts
- Navarre, Florida

If you have a question in mind which seems off topic, please Search the Site

ADD a Q, A, or Comment on THIS topic START an UNRELATED topicView CURRENT HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2019, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.