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
-
A Chromium Plating Overview
An overview of decorative and hard chromium electroplating processes.
-
Advantages to Pumped Eductor Agitation
Not all agitation methods are created equally. Pumped agitation with eductor nozzles can improve process tanks and quickly show a reduction in operating costs while keeping staff safe, following environmental legislation and preventing pollution.
-
Troubleshooting Alkaline Zinc
One of the most common problems that can arise when plating with alkaline zinc is an imbalance of brightener in the solution. In this helpful Ask the Expert article, Chad Murphy of Columbia Chemical discusses how different zinc metal concentrations and brightener concentrations can impact efficiency.
