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Lubricity of cobalt
2

Lubricity of cobalt

Lubricity of cobalt

(OP)
Anyone know any info on this.  Tried searches on line and in libraries.   Have request into cobalt industry group.  

Tom

RE: Lubricity of cobalt

You picked a hard one as most of the latest information about cobalt is under lock and key.

You might find some properties on cobalt

At one time there was an very informative booklet called "COBALT" published by:

"Union Miniere” of Belgium, who at one time controlled most of the cobalt used in the West.  A lot of technical libraries received this booklet and some still may have it in the stacks or better yet on microfilm.

They have a new name Umicore at:

http://www.um.be

You could check with them to see if they still have all the information they gathered on Cobalt and if not where is it located.

RE: Lubricity of cobalt

(OP)
Thank you.

I emailed them and will try to run down the booklet.

Thank you.

 

RE: Lubricity of cobalt

I would still check with the libraries as they were a periodical, though there was one large booklet.

RE: Lubricity of cobalt

Smithells Metals Reference Book, 7th Edn., has a bit of info.
Table 25.1 has static friction data for very clean pure metals (self-mated) in both vacuum and in air.  Cobalt was lowest for each condition, e.g., 0.3 in air vs. 0.4 for chromium, which was next lowest.

Figure 25.2 ‘Tendency of metal couples to adhere together’ ranks pairs of 19 different metals from 1 – least adhesion, best wear resistance to 4 – most adhesion, worst wear.  For most combinations, Co is about the same as Cr, Ni & Fe.  It is slightly better vs. Al, Au, In & Ti.  Worse than Cr vs. Cu, Sn & Zr.

Adhesion is greatest for those metals sharing the same crystal structure and/or forming intermetallics. Also, the thickness of the surface oxide matters – stainless steels and nickel-base alloys having very thin films, do not have good adhesive wear resistance and can gall.  As the chemistry of Co is similar to that of Ni, similar behavior is likely.

A search for galling resistance may help.

You might also try suppliers of Co plating chemicals as to the deposit properties.

RE: Lubricity of cobalt

(OP)
Amazing, just amazing.

Thank you very much.

RE: Lubricity of cobalt

At elevated temperatures high cobalt alloys form a scale which is somewhat lubricious. That is, at red heat cobalt alloys are less likely to gall than are nickel base alloys.

James Kelly
www.rolledalloys.com

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