Aluminum Alloy?

Are there any consultants / companies nearby that have a handheld analyzer, such as:

http://www.niton.com/NITON-Analyzers-Products/xlt.aspx

Depending on your location (and theirs) they should charge too much to visit and shoot that piece for you.

***** EDIT ************

That should be: ................ they should NOT charge too much

I think you were right the first time.

Scratch it with any sharp tool, then scratch a piece of soft sheet aluminium, or do the comparison with a file. I think you will feel the difference if it's an alloy (I'm willing to be shot at here).

Alternatively see how it marks a sheet of paper, soft raw aluminium will leave a grey mark I think? Someone stop me here before I make a complete wombat of myself.

Del

Gimme that keyboard!

Keep it up Del wombats are far nicer than cats.

It sounds like you are advocating the medieval touchstone technique.

BAB

Apply the method developed by Archimedes to determine if the jewelry was made of pure gold.

#1 uses this approach.

It is likely 6061, though the heat treat would still be an unknown. Most likely T651. 6061-T651 is frequently used as extrusion stock.

NO! Scratch test. NO! sniff test. NO! kick the tire test. There is no way to tell what alloy you have without an accurate spectral analysis. Find a lab with the equipment and carry the piece to them to avoid callout charges. Or cut a small piece ( check with the lab to determine there minimum sample size first). Sorry for the bad news but as a retired from 25 years of spectral analysis metallurgist, I know for a fact it is the only way. On the cheap find a spectral analyzer salesman and have him demonstrate his machine on your piece, but be prepared for the sales pitch (LONG and PERSISTANT).

There are 50 pages of aluminum alloy combinations with 15+ alloy combinations per page in the UNS reference book alone. I repeat, A spectral analysis is the only sure method.

There is no way to tell what alloy you have without an accurate spectral analysis.

Correct..you can't tell what alloy it is..but you can tell if it's an alloy rather than pure aluminium.

If you take a bar of 20x5mm alloy and flex it it is vastly different to plain aluminium.

I have made very nice crossbow prods on this basis.

After all the whole point of making an alloy is to change the properties....

Del

I hate to dissagree with the Cat Man but a bend test only guestimates mechanical properties and many unheat treated alloys have the same mechanical properties as pure aluminum.

The reagent test will give you a best guess of the series of Aluminum alloy i.e. 1000, 2000, 5000, 6000 etc. but that is the best you can hope for. Also if you do a google search for the kits you will find they cost a lot more than a single spectral analysis whether it be XRF, SES, or some other method.

If it's pure Aluminium it will soften or puddle at 1320° and catch fire at 1380°

That's great,what alloy and there is know pure aluminum it is all alloyed,either acis test or get an inexpensive chemical analysis,simple,let's not complicate our lives,do not go and heat the aluminum up,not safe.

Think of the fun that could be had heating up a big lump of Aluminium until it melts and monitoring the temperature accurately to determine which alloy it is. Then casting it into the shape you want.

Dam hard getting it to heat evenly and even harder to record the temperature at which it goes soggy.

Still lots of fun.

BAB

sounds like a whole lot of fun,what else do you Aussies do for fun? Next time I need someone to melt down my scrap, I will surely give you a call and you can watch the smelters,you know what is really A whole bunch of fun is a Magnesium fire,you'll be there forever.

Isn't that the truth.

For even more fun and excitement just add water.

BAB

very good,I was having a stressful day and read your comment,I've seen water on a Mag fire pretty fun to watch as long as it isn't your yard going up in smoke or fire,you Aussies sound like you have whole lot of fun.One more note a Mag fire sure helps in roasting meat.

"One more note a Mag fire sure helps in roasting meat." From how far away? LOL

you can contain a Mag fire by setting up a sand perimeter and if it isn't to large you can set up the patio chairs and using Titanium rods,you skewer the meat and prepare shish kabob's.And know that I am going down the path of silliness,I need to get back to work or they will shut down my power.Thanks for the humor!

Don't forget the LOX!

For basting!

We make some special metal powders that contain Aluminum and for doing a spectral analysis, we use only one gram of the powder and get all the other elements and Aluminum with that small sample. So you do not have to carry the vessel, but just a small amount of powder from the vessel by filing it in some unimportant place and give it to the lab for the analysis that will determine the alloy by its components.

vshwn7@aol.com

As others have noted, the only way to determine the specific aluminum or alloy composition is by chemical analysis.

However, if you just want to know the approximate alloy composition, there are inexpensive, non-destructive chemical spot tests that can be used to detect the presence (or absence) of specific alloying elements such as silicon, copper, manganese, magnesium, chromium, nickel and zinc. The procedures are described in ASM Metals Handbook, "Non-Destructive Inspection and Quality Control".

The procedures typically involve the application of a drop of sodium hydroxide solution (or other acid, depending on the element) onto the clean metal surface and observing the color change following a defined reaction time; usually 2 - 5 minutes.

The presence of any of those alloying elements would eliminate common wrought aluminum such as 1060, 1100, 1350 which are 99.0+ % aluminum.

XRF analysis will only cost $75.00. Many labs have the equipment. This analysis is a no brainer.

I do not know where you call home,take the aluminum to your local scrap yard make sure you go to a scrap yard not a junk yard, I know I would have been happy to spec the piece of Aluminun for you and I'm sure some other yards will do the same.Look in the phone book,explain what you want and I'm sure you can find some scrap yard for help.Way back in the day all we had were acid testing and it was pretty accurate.We would have contests between modern technology and old fashioned ways and we would come out pretty good,we could almost always give you the right alloy by acid testing,the memories,I'll shut up now,but honestly call your local scrap yard they should help,unless you are not living in or around fairly large cities.Good Luck.

Just a couple comments.

You will not be able to identify which particular alloy your part is without having it analyzed using a spectrometer.

The most accurate analysis of an aluminum alloy is via an "arc/spark" optical emission spectrometer. This is the device the metals producers use in their labs to certify their heats.

There are portable versions of these OE spectrometers. A couple examples are the "PMI Master" and also "ARC MET" both by Oxford Instr.

Even the latest versions of the portable XRF analyzers do not provide a highly accurate analysis (compare to OES) of aluminum based alloys, but could get you pretty close.

Yes, but the OP asked how to identify the cylinder's composition "without expensive spectral analysis." What consistutes 'expensive' is, of course, in the judgement of the OP, but certainly to have spectral analysis performed on his cylinder will cost money. And depending on the size of his cylinder, the charge for that service may in fact be greater than that of purchasing outright a new cylinder of known composition.