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metallurgical test

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carlossa52(at)gmail.com
Guest

Posted: Sat Jul 05, 2008 2:33 pm Post subject: metallurgical test

Given a piece of aluminum 0.125 thick, triangular (square), small side 15 mm - does anybody know if it is possible to determine if it is actually 6061-T6?



An actual reference (as a specific lab name) would be great.

 

Thanks



Carlos



do not archive.

  [quote][b]

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Sat Jul 05, 2008 3:23 pm Post subject: metallurgical test

It's certainly possible. The 6061 identifies the alloying elements  

added to the aluminum and the T6 identifies the heat treat process. A  

mass spectrometer would be one way to confirm the 6061 specification  

and a hardness test could then probably verify the T6 specification.  

I'm no expert but a good metallurgical lab should have no trouble with  

this identification. Maybe a university lab would have the needed  

equipment.



On Jul 5, 2008, at 6:29 PM, Carlos Sa wrote:



 	  Quote: 	
		   Given a piece of aluminum 0.125 thick, triangular (square), small  

 side 15 mm - does anybody know if it is possible to determine if it  

 is actually 6061-T6?



 An actual reference (as a specific lab name) would be great.



 Thanks



 Carlos




	




-- 

Bryan Martin

N61BM, CH 601 XL,

RAM Subaru, Stratus redrive.

do not archive.

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

carlossa52(at)gmail.com
Guest

Posted: Sat Jul 05, 2008 8:49 pm Post subject: metallurgical test

Right, I did find at least two labs that will do it, one of them a 5 minutes drive from home.

The 6061 specification requires about 1g of material (and costs $160).

The T6 test (tensile) requires samples 2" long for one lab case and 5" long for another ($70 per test).

 

Problem is, my sample is that small 0.125 thick, square triangle, small side 15 mm. A bigger sample destroys the subject of the testing.



I was hoping somebody on this list would have gone through this... I guess not, but thanks, anyway

 



Carlos



2008/7/5 Bryan Martin <bryanmmartin(at)comcast.net (bryanmmartin(at)comcast.net)>:

[quote] --> Zenith-List message posted by: Bryan Martin <bryanmmartin(at)comcast.net (bryanmmartin(at)comcast.net)>

 

 It's certainly possible. The 6061 identifies the alloying elements added to the aluminum and the T6 identifies the heat treat process.

 

 



[b]

grs-pms(at)comcast.net
Guest

Posted: Sat Jul 05, 2008 9:09 pm Post subject: metallurgical test

Carlos:

  

 Why not just buy some 6061-t6 with the proper  certification?  I'll bet that will be less expensive than testing what  you have?

  

 George

 [quote]   ---

carlossa52(at)gmail.com
Guest

Posted: Sun Jul 06, 2008 5:19 am Post subject: metallurgical test

Wellllllll, now I have to tell you this embarrassing story:



Some time ago I bought 6 pieces of aluminum 6061-T6 extrusion (1"x1"x0.125"), to be used on the spars.



All but one of these pieces had printed the mill's specifications on them (alloy, dimensions, mill name...).

  While at the time I trusted the vendor was selling me the material I ordered, later I became disappointed with their services. I am now concerned about the composition of the unlabeled extrusion.

Further, the parts have been primed and assembled (as in "riveted"), so I don't know which one is the "suspect". I  need to verify the six of them to be sure.



The alternative is to trash the spars, which includes disassembling a partially riveted outboard wing.



As you see, the lab test is expensive, but it is the cheaper (effort-wise) alternative at hand.

 

Carlos

CH601-HD, plans



2008/7/6 George Swinford <grs-pms(at)comcast.net (grs-pms(at)comcast.net)>:

[quote]        Carlos:

  

 Why not just buy some 6061-t6 with the proper  certification?  I'll bet that will be less expensive than testing what  you have?

  

 George

 



[b]

larry(at)macsmachine.com
Guest

Posted: Sun Jul 06, 2008 6:21 am Post subject: metallurgical test

Carlos,

I'd order another piece from them, requesting certification of the 

6061-T6 pieces sent and test what they send you.

Test against the known values for 6061-T6.  That's as close as it gets.



Larry McFarland 601HDS at www.macsmachine.com

do not archive



Carlos Sa wrote:

 	  Quote: 	
		   Wellllllll, now I have to tell you this embarrassing story:



 Some time ago I bought 6 pieces of aluminum 6061-T6 extrusion 

 (1"x1"x0.125"), to be used on the spars.



 All but one of these pieces had printed the mill's specifications on 

 them (alloy, dimensions, mill name...).

 While at the time I trusted the vendor was selling me the material I 

 ordered, later I became disappointed with their services. I am now 

 concerned about the composition of the unlabeled extrusion.



 *

 *

carlossa52(at)gmail.com
Guest

Posted: Sun Jul 06, 2008 6:44 am Post subject: metallurgical test

But Larry, how would that prove that all the material I bought from them in the past - and are now part of my spars - are actually 6061-T6?

What I am suggesting is that, when I bought them, someone in the warehouse pulled one extrusion out of the wrong shelf. (Of course I am hoping it is simply an honest-to-goodness piece of 6061-T6, just unlabeled).

 The only way to make sure is to cut samples form the extrusions and testing them (BTW, I got clearance from ZAC for cutting samples with these dimensions from the spars).



Thanks for the input



Carlos



 2008/7/6 LarryMcFarland <larry(at)macsmachine.com (larry(at)macsmachine.com)>:

[quote] --> Zenith-List message posted by: LarryMcFarland <larry(at)macsmachine.com (larry(at)macsmachine.com)>

 

 Carlos,

 I'd order another piece from them, requesting certification of the 6061-T6 pieces sent and test what they send you.

 Test against the known values for 6061-T6.  That's as close as it gets.

 

 Larry McFarland 601HDS at www.macsmachine.com

 do not archive

 

 Carlos Sa wrote:

  	  Quote: 	
		   Wellllllll, now I have to tell you this embarrassing story:

 

 Some time ago I bought 6 pieces of aluminum 6061-T6 extrusion (1"x1"x0.125"), to be used on the spars.

 

 All but one of these pieces had printed the mill's specifications on them (alloy, dimensions, mill name...).

 While at the time I trusted the vendor was selling me the material I ordered, later I became disappointed with their services. I am now concerned about the composition of the unlabeled extrusion.

 



 	
[b]

carlossa52(at)gmail.com
Guest

Posted: Sun Jul 06, 2008 9:13 am Post subject: metallurgical test

In case somebody ever finds him/herself in the same predicament, I found a tool made for just this situation:

http://www.worldoftest.com/pdf/Webster.pdf

Questions is, does it cost more than an HD wing?

 I sent them a note, stay tuned (if you care).



Carlos



2008/7/6 Carlos Sa <carlossa52(at)gmail.com (carlossa52(at)gmail.com)>:

[quote] Wellllllll, now I have to tell you this embarrassing story:



Some time ago I bought 6 pieces of aluminum 6061-T6 extrusion (1"x1"x0.125"), to be used on the spars.



All but one of these pieces had printed the mill's specifications on them (alloy, dimensions, mill name...).

   While at the time I trusted the vendor was selling me the material I ordered, later I became disappointed with their services. I am now concerned about the composition of the unlabeled extrusion.

Further, the parts have been primed and assembled (as in "riveted"), so I don't know which one is the "suspect". I  need to verify the six of them to be sure.



The alternative is to trash the spars, which includes disassembling a partially riveted outboard wing.



As you see, the lab test is expensive, but it is the cheaper (effort-wise) alternative at hand.

  

Carlos

CH601-HD, plans

[b]

Brady

Joined: 26 May 2008
Posts: 182
Location: Poulsbo, WA

Posted: Sun Jul 06, 2008 12:09 pm Post subject: Re: metallurgical test

Carlos,

I had a friend in a similar situation.

Fortunately he is a structural engineer at the navy ship yard and had access to all of the facilities assets in this discipline.

The test that he settled on was a hardness test.

His thinking was that if the aluminum was not 6061 t6 it was a 3xxx series and would be way off. so using a known 6061 t6 sample he got a base line measurement and then tested the suspect sample.

He was surprised to find that not only was he correct in his theory but also that the difference is staggering! 



I have been able to simulate this test with out the expensive machinery by using an automatic center punch. Punch a piece of 6061 T6 and notice the divot left by the tool. Then punch the sample you suspect. If there is no noticeable difference the chances are excellent that you have the same alloy.

If you have a substandard alloy the divot will be noticeably deeper.

Obviously this method is not completely accurate or totally reliable but it is enough to tell you if you are with in the extremes.



Hope this helps,

Brady

_________________
Brady McCormick
Poulsbo, WA
www.magnificentmachine.com

bcchurch

Joined: 10 Dec 2007
Posts: 25
Location: Racine, WI

Posted: Tue Jul 08, 2008 5:17 pm Post subject: Re: metallurgical test

Carlos,



I'm a materials engineer and would like to offer my advice.  What you should do is confirm a) chemical composition and b) mechanical properties.  Chemical composition can be done easily via ICP or OES and your sample is definitely large enough for either test.  The price you listed seemed reasonable - just make sure the lab gives you actual results and not just a "meets 6061" statement.  You want to know actual weight percent of silicon, magnesium, iron, manganese, etc.  



The more difficult issue for you is mechanical properties.  



The 6061-T6 spec calls out yield, tensile, and elongation which are all determined via a standard tensile test.  As you already know, the size of your sample is too small to perform a tensile test.  My opinion is that you should ask for hardness tests on your unknown sample as well as a known 6061-T6 of the same thickness.  Hardness is not the ideal way to do this - but given your situation it's the best-possible way.  



If chemistry checks out, then go ahead with the hardness tests.  If the hardness results of the known and unknown are similar (I very much doubt they will be exactly equal) then I'd say you're good to assume your 6061 is indeed T6.  I'd also double check the hardness results of both known and unknown samples versus "handbook" values for 6061-T6 for added comfort.  The hardness tests would not be definitive proof - but it would be good enough for me if I were in your shoes.  



Hope this helps.  Feel free to email me at bcchurch-at-yahoo.com if you have any questions.



Regards,

Ben

_________________
Ben Church
CH801
Racine, WI

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