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Copper coating + Hard chrome plating - reg

2006

Hello everybody,

I would like to know that, what will happen if I Plate Hard chrome on Already copper coated steel samples, instead of direct Hard chrome plating on steel.

1. What will be the adhesion or bonding force between copper plating and hard chrome.

2. what will be the effect on surface roughness Ra if I plate hard chrome on copper coated samples.

3. Can I use this copper + hardchrome plated samples for the application which involves higher load or Higher RPM? Can this combination take load or not? Is there possibility of peel-off or worn out problem?

Kindly explain me in details.

Awaiting your valuable replies.......

Thanks in advance...

yours,

K.Chandrasekaran
LMW - Coimbatore, TamilNadu and India

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2006

My favorite response - IT DEPENDS! copper has been used as an underplate on things like rough cast iron for years.
So, how good is the copper plate?
Chrome is regularly used over soft nickel that is used as a build up material and is very low internally stressed vs the extremely high internal stress of chrome.
For a critical operation, my personal preference would be to not use a copper underplate.
Copper underplate will not affect the chrome surface roughness. The surface roughness of the part, with or without the copper, will affect the chrome surface.
It is a mute point as you should be grinding the part after chrome plate or you have the worlds finest plater or have no diameter requirements.
Now for a reply in detail, that would take several reference books.

James Watts
- Navarre, Florida

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The only thing I would add is that the required thickness of hard chrome for an application can depend on the hardness of the underlying substrate. You might only require a few ten thousandths of an inch thickness of chrome on steel if that steel is hardened. But if you added a significant thickness of substantially softer copper, you might need several thousandths of an inch of chrome before you would have a hard wear-resistant surface.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006