%IACS values

[Somber]

I have been searching for a definitive listing of %IACS (International Annealed Copper Standard) values. I found a lot of online sources that had varying levels of information, but no single listing that seemed to cover the entire spectrum - and most were very poor with referencing their source material. I'm hoping some of you may know a good reference that is well documented - or where I can get my hands on the standards themselves. Please don't limit yourselves to online info, I'd be happy to pay for a good book or reference.

Here is an example where this was needed. Two 2024-T62 panels were briefly exposed to extreme temperature exaust. The technical data called out for NDI to perform electrical conductivity checks of the material to ensure that the material properties of the effected areas have not been compromised. I found several sources for %IAC range for 2024-T62 Aluminum, but none that in turn listed their source of that information.

So - if any of you have "been there done that", I'd appreciate not having to dig around any more than I have to...

Thanks in advance...

 

[TVP]

ASM HANDBOOK Volume 2 Properties and Selection: Nonferrous Alloy and Special-Purpose Materials lists the electrical conductivity of most aluminum alloys (limited to commercial alloys prior to ~ 1990). It shows that 2024 in the peak-aged (T6) or over-aged (T8) condition should have conductivity = 38% of IACS.

Another reference that will contain this same data is ASM SPECIALTY HANDBOOK Aluminum and Aluminum Alloys. Other references to investigate are Aluminum: Properties and Physical Metallurgy and Aluminium Handbook, Volume 1, Fundamentals and Materials. All are available from ASM International:

http://www.asminternational.org/Template.cfm?Section=Bookstore&Template=/ecommerce/ecomdefault.cfm

 

[KSshopper]

Be careful doing an "absolute" conductivity measurement as many factors can alter your results. Liftoff caused by paint, cladding etc will cause your reading to vary. Also, the back-up structure and material thickness will vary the reading as well.

A better approach is to do a relative measurement. Start taking measurements far away from the exposed area, that is where you're confident the panel is "good". Then bring your probe in towards the location of heat damage until you mark a 1 degree change in %IACS. If you do this from several different directions, you can map the extent of your damage, and the effects of lift-off, thickness, etc will be taken care of since your readings are relative.

One final tip, keep your relative measurements consistent with the back up structure. That is to say measure your change along a consistent path (along skin only, along a stringer, along a splice, etc)

 

[Somber]

TVP - thanks for the resources...

philcondit - I agree, we did take relative/comparitive measurements... and all measurements taken included liftoff factors...

I still wanted to be able to referece a solid source for a baseline value for 20204-T62 in my response. I found the information, but "some website" doesn't stand up to scrutiny very well... I worked the issue - I just wanted to make sure that I had better resources set up for the next time this issue comes up...

anyone else - please chime in...