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Chrome plating of titanium crankshaft

I am trying to plate hard chrome on some titanium body valves and am having adhesion problems. Does anyone have a tried and true way to accomplish this?

David Ackley
- Peoria, Arizona, USA
2002

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The ASM Metals Handbook volume on "Surface Engineering" ⇦[this on eBay , Amazon, AbeBooks affil links] has some info on prepping titanium. But I am told by a trusted party that the only way you get truly reliable adhesion on titanium is with a diffused nickel coating: prepare the surface as suggested by the Metals Handbook, nickel plate it, and bake it to diffuse the nickel into the titanium. There is an ASTM spec for this prep method but I don't know it offhand.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

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David and Ted,

The ASTM specification is ASTM B481 Standard preparation on titanium and titanium alloy.

Sincerely,

Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
2002

Ed. note: Thanks, Anders!

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Multiple threads merged: please forgive chronology errors :-)

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Q. I wish to experiment with the use of titanium for use as a crankshaft in an experimental lightweight engine. I understand that titanium will not run in conventional bearing material, so I need to plate the crankshaft bearing journals with hard chrome. Does anyone have information on the plating process, or any other coating?

Stuart Pearson
- Christchurch, New Zealand
2002

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2002

A. There are procedures for plating titanium listed in ASM Metals Handbook, vol. 5, Surface Engineering. But I am told by someone who knows more about it than me, that the only way you'll really plate titanium successfully is to nickel plate it and then heat it hot enough for the nickel to diffuse into the titanium. There is an ASTM standard for this.

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

A. I had a crankshaft chrome plated for an experimental 65 hp engine originally produced by Continental. It was .020 undersized and plating brought it back to standard. After 500 hrs of use the crankshaft was in perfect shape and oil analysis showed no wear at all. I had it done by a company in Milford Delaware. The cost was minimum compared to the cost of a standard crankshaft. This method can only be used in non-certified engines as I have been unable to find any approval for it for certified engines. I got the idea from a very old military maintenance manual where it was used for round engine cranks. I figured if it could handle the stress of a round engine than it should be fine for an engine turning only 2300.00

David Henderson
- Rehoboth Beach, Delaware
2004

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Thanks, David! The chrome platers on this forum will be happy to hear of your satisfaction. However, few crankshafts are titanium, so unless you tell me otherwise, I have to doubt that your crankshaft was titanium. Successfully plating a titanium crankshaft is an awful lot harder than plating a steel one.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

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Please mention chromium plating solution for titanium and a standard number that you mentioned at above (standard for diffusion nickel plating on titanium)

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