Removing Nickel Plate from Kovar
Question: What is the safest way to remove nickel plate from Kovar?
Question:
What is the safest way to remove nickel plate from Kovar? We tried using 50/50 nitric acid and ended up damaging the parts. K.S.
Answer:
Kovar is an alloy of iron (~50%) and nickel (~46%) with small amounts of other "goodies" added. As you already have found out, stripping of a plated deposit is never a straightforward autopilot process. Mixtures of sulfuric acid and nitric acid are sometimes used but if you are not averse to using a cyanide-based solution you might try the following:
- Sodium cyanide 10 oz/gal
- Sodium hydroxide 2 oz/gal
- m-nitrobenzene 4 oz/gal
- sulfonic acid
- Temperature 120-150F
Keep in mind that this is a cyanide containing solution and must be handled with great care. The waste from this stripping solution must be disposed of properly. There are a large number of companies that sell proprietary non-cyanide containing stripping solutions. You can find them listed under Stripping Solutions, metal on the Suppliers page at PF Online or in the 2001 Products Finishing Directory & Technology Guide.
Related Content
-
How to Choose Between Sulfate and Chloride-Based Trivalent Chromium
There are several factors to consider when choosing between sulfate and chloride-based baths for trivalent chromium plating. Mark Schario of Columbia Chemical discusses the differences and what platers should keep in mind when evaluating options.
-
Possibilities From Electroplating 3D Printed Plastic Parts
Adding layers of nickel or copper to 3D printed polymer can impart desired properties such as electrical conductivity, EMI shielding, abrasion resistance and improved strength — approaching and even exceeding 3D printed metal, according to RePliForm.
-
How to Maximize Nickel Plating Performance
The advantages of boric acid-free nickel plating include allowing manufacturers who utilize nickel plating to keep up the ever-changing regulatory policies and support sustainability efforts.