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Eddyfi
Pursuing and developing eddy current array (ECA) technology to its full potential.

926 views
04:52 Sep-29-2005

Ron Olson

R & D, Aerospace
The Best Aviation Company In The World,
USA,
Joined Feb 2005
23
Metals and Conductivity

Can an unknown aluminum alloy be strictly determined by conductivity? Thank you.


 
00:42 Oct-01-2005

Joe Buckley

Consultant, ASNT L-III, Honorary Secretary of BINDT
Level X NDT, BINDT,
United Kingdom,
Joined Oct 1999
515
Re: Metals and Conductivity Simple answer: No
Typically Aluminium Alloys cover quite a range of conductivity depending on Heat treatment state.

The relationship between heat treatment and conductivity is complex: Many alloys (e.g. the common 7075 type) follow a circular curve with heat treatment/work - Even knowing the alloy composition you cannot reliably tell the full state from conductivity - often need hardness as well.

What you can do is use conductivity as a check- If an alloy has the conductivity you expect it is 'likely to be correct', or more precisely, if it is different something is wrong, but you cant work back to deduce much, with a high degree of certainty, if you only know conductivity.

If you can make a few more assumptions it becomes a lot more useful. Typically a shop may only work with a few different alloys, so conductivity can be used to check which one you have.

If you 'know nothing' you need hardness and PMI checks as well

Joe


----------- Start Original Message -----------
: Can an unknown aluminum alloy be strictly determined by conductivity? Thank you.
------------ End Original Message ------------




 
05:32 Oct-02-2005
Carl Berrojo
Re: Metals and Conductivity ----------- Start Original Message -----------
: Can an unknown aluminum alloy be strictly determined by conductivity? Thank you.
------------ End Original Message ------------
No, due to the overlapping conductivity values of aluminum alloys (ie. 2024-T3 is 28%-32% IACS and 7075-T6 is 30%-35% IACS). Normally, you would identify the alloy with acid testing (we use kits provided for this purpose by Scientific Systems Laboratories), then use the conductivity value to determine the temper (heat treat condition).





 
02:13 Oct-02-2005

S.V.Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
783
Re: Metals and Conductivity Dear Ron,

No. The conductivity is just one of several parameters. You will need a spectro or XRF spot analysis, if you don't want to cut a piece and send it for conventional chemical analysis. Strength and hardness data will tell you about heat treatment.

Swamy

----------- Start Original Message -----------
: Can an unknown aluminum alloy be strictly determined by conductivity? Thank you.
------------ End Original Message ------------




 


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