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Alternatives to chrome plating for cylinder rods

We are looking for alternatives to chrome plating for cylinder rods. Are there some cost competitive options that have superior corrosion resistance?

Lloyd Blumenstock
Fargo, North Dakota
1999

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Corrosion resistance isn't usually the real issue, Lloyd, oil holding capacity is. Electroless nickel is far superior to chrome in corrosion resistance, and has replaced it in some instances, but many cylinder applications of it were unsuccessful, only partially successful (requiring electroless nickel with a flash of chrome) or required a good deal of development work. Fortunately, you're not early into this and a diligent literature search will reveal published case histories. Good luck,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
1999

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How thick is the chromium coating? If it's fairly thin (under 0.0005"), a PVD coating might be able to replace the chrome. If it's particularly thick, you might try either thermal/plasma spray or electro-spark deposition.

Jim Treglio - scwineryreview.com
PVD Consultant & Wine Lover - San Diego,
California
1999

You will be hard pressed to find any other process, regardless of cost, that would outperform standard hard chrome plated bar stock used for hydraulic rod applications. You do not mention why you are looking for hard chrome replacement. We assume that it is not a quality issue.

If you have a well funded research budget many different coatings are now available. I would suggest starting with PVD coating TiN. The hot (700 F) process is better than the cold (400 F)!

Regards.

Stephen C. Ward
- Canada
1999

Lloyd:

Chrome plating is under some threat, as you may know, by environmentalists and hardened nickel is under some discussion as an alternative. We have done some research into replacing steel coated with chrome, by solid nickel with an outer layer of hardened nickel. Under consideration in parts of the aerospace and defence industries in US and Canada.

If the nickel pieces (cylinders or other parts) are formed by chemical vapour deposition (CVD), there is no layering, or risk of delamination, because the outer layer of hardened nickel is completely bonded to the backing layer, in one continuous deposition process.

Mick O'Meara
- Toronto, Canada
2000

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Hi, Lloyd. Many small cylinder rods like the air lifts for auto tailgates are salt bath nitrided. See the article in our library by Kolene.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February 21, 2009