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rolland
08-28-2011, 03:59 AM
On the tv program "How do they do it" they were making fuel lines for a jet airliner engine. A close up of the tube showed "6061" so now we know what aircraft grade is.
No mention of billet was made. The welder putting it together was a master at welding the fittings.

PixMan
08-28-2011, 08:25 AM
Actually, there are many "aircraft grades" of aluminum and other metals. Other alloys used in aircraft include 7075, 5052, 2024 and 3003, all in different tempers and approved or use in different areas of application.

No approved "billet" that I know of. ;)

topct
08-28-2011, 10:06 AM
Actually, there are many "aircraft grades" of aluminum and other metals. Other alloys used in aircraft include 7075, 5052, 2024 and 3003, all in different tempers and approved or use in different areas of application.

No approved "billet" that I know of. ;)

We made all those alloys and a few odd ones at the local Kaiser rolling mill. There was no difference in the quality of the metal used for aircraft and that destined for other uses. Those that were going to the aircraft industry where different only at the paper trail level. They are all "traceable" back to the ingot the were rolled from. They did go through various additional testing and the results recorded but the bottom line was we made it all the same way no matter where it finally went.

lynnl
08-28-2011, 11:13 AM
I saw one of those programs (How do they do it, How it's made, Factory made, etc.) several months back. This one dealt with the large structural members, wing spars, etc. They were at a huge Alco plant in Iowa City, or Davenport, ...or somewhere in Iowa.
I'm pretty sure the Alcoa man, foreman or supervisor, being interviewed said it was 7075 they were using for the members in question.

J Tiers
08-28-2011, 11:22 AM
it's probably a meaningless term.

Not only are many standard grades used, but the most "aircraft associated" type (not grade) is "alclad", which has a core of an alloy, but the sheet surfaces are a pure aluminum for better corrosion behavior. That is of no benefit for many other uses.

"Billet', or block/bar/etc, used to be used for prototype fittings, which were milled out of stock bar before the forge tooling or extrusion dies, etc, were made.

Evan
08-28-2011, 01:52 PM
The term "aircraft grade" has no meaning in the standards. The alloys used also have no special "aircraft" designation. Much of that goes back to the early days of the use of aluminum in aircraft when specific alloys were developed for use in aircraft. The characteristics that make an alloy useful in aircraft also make it excellent for truck trailers and canoes as well as inumerable other applications.

Alclad, as Jerry mentions is an exception. The layer of pure aluminum greatly increases corrosion resistance without a change in weight. In ground based applications paint or anodising serves fine but paint weighs a lot on a large aircraft. The paint on a 747 weighs around half a ton and it complicates inspection processes.

Now the distinction is even less applicable as there are many different variants of the 7000 series and the 8000 series that are used in aircraft as well as metal/composite sandwich materials such as "Glare" used on the Airbus 380.

PixMan
08-28-2011, 03:53 PM
"Aircraft Grade" is the new "billet"!

psomero
08-28-2011, 04:01 PM
We made all those alloys and a few odd ones at the local Kaiser rolling mill. There was no difference in the quality of the metal used for aircraft and that destined for other uses. Those that were going to the aircraft industry where different only at the paper trail level. They are all "traceable" back to the ingot the were rolled from. They did go through various additional testing and the results recorded but the bottom line was we made it all the same way no matter where it finally went.



I think Kaiser's operations are a bit of an extreme example, so this is why both classifications of material (aircraft, non-aircraft) were the seemingly identical.

If you were to look at a facility in some other country, on the other hand, there may be a vast difference between aircraft grade and stock that is not specifically certified as such.

basically, it's great that Kaiser makes all of their material to meet or exceed aircraft specifications. that doesn't guarantee that everybody else has such high standards for all of their work.

Evan
08-28-2011, 04:20 PM
There aren't "aircraft specifications". There are alloy specifications along with treatment specfications. Either the material meets those specs or it doesn't. 2024-T4 either meets the spec or it isn't 2024-T4 regardless of what it will be used for.

demerrill
08-28-2011, 06:03 PM
One may also encounter the terms "aircraft quality" or "gun quality" in reference to steel stock. See, for example, http://www.timken.com/en-us/products/Steel/productlist/barsbillets/Pages/quality.aspx.

This terminology usually purports to denote steel made with high purity melt practices which minimize the percentage, size and shape of various inclusions of impurities in the steel. Inclusions relate to the fracture resistance (as opposed to tensile strength) and fatigue strength (resistance to crack formation and propagation due to cyclic loading) and to some other categories of crack behavior. While this type of quality level may be certified by the steel producer, the precise means of characterizing it and assuring compliance is sometimes a matter of contractual agreements between the individual steel producer and the individual manufacturing user. The final assurance of compliance may rest with the using manufacturer's metallurgy department or consulting metallurgical services. Think cutting, mounting, polishing, etching and microscopic examination of samples (possibly electron microscope examination) followed by magnetic particle inspection and proof testing of finished parts.

And, of course, such quality claims are always subject to casual misuse by marketing types and others who have no idea what they're talking about.

Some things to think about if one is tempted to make highly stressed gun or aircraft parts out of warehouse supplied steel, or from drops (most likely place to find 'stringers' and other inclusions) and other scrap sources.

Any place that a hobbyist could routinely obtain small quantities of such certified quality steel ? None that I am aware of.

David Merrill

boslab
08-28-2011, 06:54 PM
an interesting post, well written and accurate, its easy to make aircraft grade anything, its about tracability, whilst it may be aircraft grade it does not guarantee that any finished component is going to be any better than one made from the same grade product non aircraft, ie limited tracability. very few companies sell thier steel/ali whatever on chemical analysis, its made to a range of chemistries [ie min/max unilateral or bilateraly as you like as far as tollerance goes]
These chemistries are designed to give the material certain mechanical properties, the material is usually sold on these properties and no guarantee of a precise chemical composition, just a min/max as i have said, the manufacturer will in aircraft grades be able to trace the material throughout its production, right back to which ship the ore arrived in, when, from where, wher mined etc, a lot of attention is given to what we call 'tramps' minor chemical elements that provide a fingerprint of a cast, like Vanadium, moly, cobalt, osmium arsnic whatever, they provide a means to identify the metal component even from a small fragment, its not unusual to dope a cast with a known element to ensure it actually belongs to you, handy in litigation , samples are retained for 10 years normally but if critical then indefinite.
inclusion modification of steel is best acheived with niobium ive found, the stringy accular inclusions will turn into beads, less stress concentrators, common practice in pipeline steels, less prone to cracking
regards
mark

morehelium
08-28-2011, 09:15 PM
ummm....

I think the OP was trying to be sarcastic.

Predictable responses from some though.

Magnum164
08-28-2011, 09:24 PM
Aircraft Grade Aluminum = Old Term

Aircraft Grade Carbon Fiber - New Term

:)

Evan
08-28-2011, 10:18 PM
Just wait a few minutes. Shortly we will be seeing "C60 carbon Nanotube reenforced polyaxial crosslinked mettalo-organic composite billet".

lynnl
08-29-2011, 01:03 PM
Just wait a few minutes. Shortly we will be seeing "C60 carbon Nanotube reenforced polyaxial crosslinked mettalo-organic composite billet".

I understand the National Institute of Scatological Sciences (NISS) is working on that at this very time.
According to NISS it's believed that such an advancement in material development will play a large role in the subsequent successfull re-engineering at Rockwell labs, of the turbo encabulator, in order to bring down production costs and make commercial deployment economically feasible.

http://www.youtube.com/watch?v=2fjcJp_Nwvk&NR=1

tdmidget
08-29-2011, 11:11 PM
One may also encounter the terms "aircraft quality" or "gun quality" in reference to steel stock. See, for example, http://www.timken.com/en-us/products/Steel/productlist/barsbillets/Pages/quality.aspx.

This terminology usually purports to denote steel made with high purity melt practices which minimize the percentage, size and shape of various inclusions of impurities in the steel. Inclusions relate to the fracture resistance (as opposed to tensile strength) and fatigue strength (resistance to crack formation and propagation due to cyclic loading) and to some other categories of crack behavior. While this type of quality level may be certified by the steel producer, the precise means of characterizing it and assuring compliance is sometimes a matter of contractual agreements between the individual steel producer and the individual manufacturing user. The final assurance of compliance may rest with the using manufacturer's metallurgy department or consulting metallurgical services. Think cutting, mounting, polishing, etching and microscopic examination of samples (possibly electron microscope examination) followed by magnetic particle inspection and proof testing of finished parts.

And, of course, such quality claims are always subject to casual misuse by marketing types and others who have no idea what they're talking about.

That is exactly what this "gun quality" is. It is a stretch based on the fact a Timken alloy is, or has been, used for M16 barrels. Nothing special about it.

Some things to think about if one is tempted to make highly stressed gun or aircraft parts out of warehouse supplied steel, or from drops (most likely place to find 'stringers' and other inclusions) and other scrap sources.

Any place that a hobbyist could routinely obtain small quantities of such certified quality steel ? None that I am aware of.
What is a "small quantity" ? Service centers such as Jorgensen have certs on everything they sell. Just ask.

David Merrill
............

boslab
08-29-2011, 11:33 PM
where do i buy aircraft grade billot polycarbonate,[ 10" x 10", you know billot size?]
mark

doctor demo
08-30-2011, 12:33 AM
You Guys are so last week.... the good stuff is "Aerospace Approved"

Steve

boslab
08-30-2011, 02:06 AM
your right of course but it keeps us all amused, lets be honest if your even logged onto a site like this then i reckon a] you got no mates! b] your more than a little odd [these observations provided by my other half whils being annoyed with me!]
In truth there appears to be more than a little truth there, i dont think i really do know anyone in my area with similar interests!, dont see many folk getting excited with a miller with dividing head on do you?
Aircraft aluminium, billot ali. and such like have been the bread an butter of arguments for years i reckon itll keep us at it for a few more.
Men in sheds rule!
regards
mark

loply
08-30-2011, 11:15 AM
Aircraft grade, pah, that's so 1910.

"Space Age" materials are where it's at. Developed for NASA.

MrSleepy
08-30-2011, 11:33 AM
Just wait a few minutes. Shortly we will be seeing "C60 carbon Nanotube reenforced polyaxial crosslinked mettalo-organic composite billet".


Formula 1 banned the use of Metal Matrix Composites (a mixture of aluminium and ceramic fibre) due to the cost, for the 2010 season.
It was used to produced extremely stiff lightweight components for suspension components etc..

Rob