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Zinc-Nickel as replacement for cadmium

1996

I am a graduate student in the Engineering Management Department at University of Missouri -Rolla. I have been performing research pertaining to environmental issues. I found your homepage in the netscape and I thought the area I am working on is related with your area and I can get some information from you.

Recently we have been searching for a method which can be alternative to Cadmium plating. Currently, several process have been applied as cadmium plating replacement process. Our main concern is Zn-Ni plating and its application on the hi-strength steel (220 KSI & up). We have identified that, there are two types of Zn-Ni plating process to address:

• - Zn _ Ni Acid - Pure coating.
• - Zn _ Ni Alkaline - Courter - Hall.

We have some concerns regarding these two processes and would like you to help us to come up with conclusive answers.

• 1. Research on the current usage at hi-strength steel (220 KSI & up) for both type.
• 2. Research if there is any restriction for both type in actual usage at 220 KSI and above.
• 3. Research on Hydrogen embrittlement resistance data.
• 4. Fatigue test data with comparisons to cadmium or bare metal plating.
• 5. Research on the capability of plating uniformity with comparison tocadmium plating.
  • - Research current methods.
  • - Capability of plating flat surface.
  • - Capability of plating complex surface.
  • - Capability of plating internal surface such as cylindrical parts.
• 6. Research bath capabilities such as consistency, stability and acceptable bath range.
• 7. Research on the current methodology for accomplishing stripability requirements.
• 8. Research for environmental concerns.

We appreciate your support of this important environmental project and would like you to help us to answer some of the above concerns and questions. Thank you your time and concern.

Best regards,

Adil Burcin Poyraz
Rolla, Missouri

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A. What are the specific applications? There is no single across-the-board substitute for cadmium because it is used for its corrosion resistance, sacrificial protection, lubricity, anti-galling, freedom from gummy corrosion products, compatibility with aluminum, malleability, and radiation-shielding properties.

Hydrogen embrittlement is a horribly complex situation and the subject of numerous recent articles in the trade journals. A literature search which includes Plating & Surface Finishing, Metal Finishing, and Transactions of the IMF should garner some references.

Any acid process is going to be inherently inferior to a cyanide process like cadmium when it comes to coverage of complex surfaces and I.D.s. because metal must be very highly complexed to overcome adverse geometrical (current density) conditions. Appreciating that, you can see that any alloy, incorporating two different metals of different nobility, is not going to readily maintain consistent metal ratios offer broadly differing current densities

You should probably contact firms who offer these processes and will have done some of the research.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Dear sir

I want all papers and information about Zn Ni plating since I work in search center for Ph.D in Zn Ni plating

Alsayed Abdel Aal Alsayed Ibrahim
central metallurgical research and development institute - Cairo, Egypt
2000