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Project on alternatives to cadmium plating

I'm investigating Cadmium plating alternatives. Could somebody send me property data about cadmium plating. (Lubricity, time to corrosion, tensile strength, cost, availability)

Mark de Waard
Student - Eindhoven, Noord-Brabant, The Netherlands
2003

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Hi Mark. I don't think you'll get there by starting with abstract data because such tables apply metrics to the proposition which obscure the story rather than tell it. For example, assigning an electrochemical activity rating to cadmium doesn't reveal why it's better than zinc except in the context of real parts in real applications. As another example, it's just about impossible to quantify what is meant by "freedom from sticky and bulky corrosion products", but there are components where this is obviously vital, and components where it really doesn't matter -- which brings me to the point: I think you have to start from the other direction.

That is, there is NO other finish that offers ALL of the strengths of cadmium plating (if it had all the properties of cadmium it would be cadmium), so you need to look at each individual part and determine what's important to that particular part. Example: if the part contacts aluminum, then the substitute finish must have good galvanic compatibility with aluminum (for example, Ivadizing or aluminum plating). If the part needs the good stick-slip properties of cadmium, then you need to pick a finish like tin-zinc plating which offers that. If the coating must be anodic to steel, but offer better protection than zinc, you may need an alloy zinc plating. If you need solderability, you may need electroless nickel plating, etc.

But your project has been done countless times already with U.S. government grant money; so just type your title "alternatives to cadmium plating" into a search engine. We can't seem to discourage them from endlessly paying beltway bandits to reshuffle the chapters of the same-old same-old report again and again, but you can abstract everything you need from those reports :-)

Best of luck with it.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003