Mystery Alloy - XRF readout inside

[fastlanesupply]

Hello, I'm having trouble identifying an alloy and figured that there may be someone here that would know where to look (the references I have checked dont have it. Anyway, attached is a pic of the XRF display.

Thanks in advance!

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http://i56.tinypic.com/2ur2ng6.jpg

]

 

[TVP]

Is there any chance that the part has a coating and that is affecting the XRF results? The reason I ask is because I don't recognize that as being a typical copper alloy based on the relative and absolute percentages. I checked a couple of references like ASM HANDBOOK and MPIF powder standards, and nothing looks close.

 

[fastlanesupply]

That was one idea I had, but the XRF readout are identical when taken on a unmachined (but filed) surface, and taken on a cut surface (also cleaned with sandpaper). In the refrences that I looked, I could find comparable Copper and Nickel but the Tin was always the oddball.

 

[mrfailure]

I'll play.

My first thought was a nickel tin bronze. However, I think som other alloys are more appropriate. Check out copper nickel tin spinoidal alloys (UNS C72650, C72700, C72800, C72900, or C72950). Of these, C72900 seems to come closest.

Aaron Tanzer

http://www.lehightesting.com

 

[fastlanesupply]

It certainly seems like we are getting closer! Though where I looked the C72900 has 50% more copper and 50% Less Nickel and Tin.

 

[mrfailure]

If a surface is not properly prepared (i.e. wire brushing off oxidized surface layers to get to pure metal), results can and do get skewed from XRF in a major way (I know from personal experience!) Is it possible that the surface was not prepared in such a manner? Oxidation likely would show a lesser than true impact of copper while magnifying the contribution of the other elements.

Aaron Tanzer

http://www.lehightesting.com

 

[fastlanesupply]

Yes, I did several readings with the XRF. All of which were on filed or sanded surfaces. The readings were consistant.

 

[stanweld]

Could be German Silver or a derivitive thereof.

 

[mrfailure]

I do not think German silver has the tin found to be a candidate.

Aaron Tanzer

http://www.lehightesting.com

 

[stanweld]

mrfailure,
Thanks. I obtained the info from a 1920's source. Went even further back to an 1883 source and it was a Copper-Nickel-Zinc alloy then and remains so.

 

[metengr]

Did you check the calibration of the machine? I have seen on occasion during field testing problems with these handheld XRF devices.

 

[Metaljon]

Similar to metengr I have some doubts about the accuracy of the PMI test. TYou should do an OES test to get a proper chemical analysis.

http://nz.linkedin.com/pub/jonathan-smith/39/25/589

 

[XRFApps]

This seems like an unusual alloy and does not closely match any UNS alloys I saw (my handbook is current as of 2008). Have you checked your instrument against some known standards that are similar in composition (other copper nickel tin alloys)?? That would identify whether you truly have a unique alloy or if it is a problem with your XRF instrument/calibration. Another way you could check the XRF would be to cross reference the results with another method such as OES. If you are interested you could send me a sample and I would verify your results using XRF...

 

[Guest102023]

XRF is STILL not chemical analysis. Best thing to do would be to compare with the nearest reference with known composition.