Need some help on Aluminum.

hungdynasty · Oct 4, 2006

I have some questions about Aluminum and I'd appreciate it if any of you can give me some ideas.

1.Is Aluminum = Aluminium?
2.Is those structure material(metal) used in Audi or Aston Martin Aluminum or Aluminum Alloy?
3.If those is Alloy, what is the ingredient other than Aluminum?

Thanks!

chas3 · Oct 4, 2006

some countries prefer the alternate (original perhaps) spelling of aluminum. i believe it was changed to be consistent with other -um elements.

pure aluminum is fairly soft and has other undesirable properties (as i recall). it is almost certainly an alloy if its aluminum.

http://www.world-aluminium.org/production/processing/alloys.html

Pablo · Oct 4, 2006

Indeed there are many Al alloys. Al pre WWII was considered exotic, and up until the late 1990's was fairly unavailable in mainland China. The recent spike is the continued demand for Al in China.

I still find it a great alloy. More cars are using it. I believe Audi does use Al frame pieces. There were some horror stories from the 70's/80's about some 4x4's (Land Cruiser/RR??? I can't remember - with some issues of stress corrosion, etc of Al frame parts. Maybe do a search.

Kestas · Oct 4, 2006

First of all, aluminum = aluminium. The second is a British spelling.

One of my colleagues joked about a problem they had with a part that checked out okay in England, yet failed during testing in the US. They said "during the trip overseas, the material changed from aluminium to aluminum!"

Anyhow, pure aluminum is rarely used in engineering applications. It is too soft and has relatively little strehgth. As a rule of thumb, any pure metal is relatively soft and weak.

Are you talking about the space frame or the sheet metal on the body? Working from memory, the space frame is made of forged, extruded, and the nodes are made of cast aluminum.

Chas3 is correct, nearly all engineered aluminum is alloyed. Many different elements are used to alloy aluminum.... Si, Cu, Mn, Mg, Zn. Chas3 provided a good link to detail on these alloys.

hungdynasty · Oct 4, 2006

So what kind of Alloy( Si, Cu, Mn, Mg, Zn...??) is used to build the car's chassis or monocoque(like Audi cars)? Thanks a lot!

Pablo · Oct 4, 2006

I don't know which alloy is actually used. Maybe you can find it at an Audi forum. I suspect something like a 6061 or 6063 in the T6 condition for the extruded pieces. For the cast pieces maybe one of the 200 series.

moribundman · Oct 4, 2006

Audi developed the Audi Space Frame beginning in the early '80s. They teamed up with US aluminum manufacturer ALCOA and the ASF was ready for mass production in '97. ALCOA is making parts of the Audi ASF in its manufacturing facility in Soest, Germany. Over 7 aircraft-grade aluminum alloys, each with different properties, are used. I doubt you will find information on what exact alloy was used for any particular component.

AW article

Kestas · Oct 4, 2006

I don't know which specific alloys are used, either. It's a good bet that 6061 or 7075 could be included. These are very popular structural alloys. Like moribundman said, they could be using any number of alloys for the space frame.

If you could get a hold of some old Ward's Auto World or Automotive Engineering magazines, they usually give that kind of info when they talk about new designs.

If I may ask, why do you need to know this detail?

mechtech2 · Oct 5, 2006

Aluminum has a metallic color. Or, in English:
Aluminium has a metallic colour.

Bret Chase · Oct 5, 2006

an important thing to know about aluminum is (I'm grasping for the proper term) that it doesn't have unlimited fatigue strength. (unlike steel) for example if you take an aluminum bolt and put a 50% load on it, eventually it WILL fail. this is very unlike steel, which will hold that 50% load indefinately (unless corrosion takes its toll). that particular property of AL is why such careful inspection is made of AL airframes.

moribundman · Oct 5, 2006

Quote:

some countries prefer the alternate (original perhaps) spelling of aluminum. i believe it was changed to be consistent with other -um elements.

You mean like plutonum and uranum?

It's actually the other way around. "Aluminum" is the older version of the word. Later it was changed to "aluminium" to match the suffix "-ium" of most other newly discovered elements. Of course, there have been calcium, platinum, molybdenum, magnesium etc. There seems to be no rule written in stone.

Pablo · Oct 5, 2006

It's numb.

rpn453 · Oct 5, 2006

The 6000 and 7000 series' are commonly used aluminum alloys, so it's probably one of those. As others have mentioned, pure metals are rarely used in a structural application.

Quote:

for example if you take an aluminum bolt and put a 50% load on it, eventually it WILL fail

. . . provided you cycle the load!

hungdynasty · Oct 5, 2006

Quote:

If I may ask, why do you need to know this detail?

My father was making a fence this morning using Aluminum bars and when I took a close look at it, I found that at the angle(bent) area, there were some scratch which really means these area were actually damaged. I was wondering how soft or weak Aluminum is and how it can be used to make automotive structure. However, I wasn't sure what kind of Aluminum(or Alloy) my dad was using and that's why I made this thread. Anyway thank you all for your info.

moribundman · Oct 6, 2006

Quote:

I was wondering how soft or weak Aluminum is and how it can be used to make automotive structure.

The properties of a material, including its weaknesses, can be exploited. Shape, profile, alloys and how components interact is very complex. Working with aluminum is not easy, and the effort and time creating the ASF design took demonstrates that. When the Audi A8 first came out, one main concern was how to repair the frame, should it get bent in an accident. In '97 I talked to the guy who had the back then only body shop in northern California with the required equipment for repairing the ASF.

When aluminum frame mountain bikes (Kettler) came out, I got one. I ruined it within a week, and I broke the replacement bike just as quickly. It's not until now, more than 15 years later that I trust aluminum frames on MTBs. The materials, production methods and design have gotten a lot better. That said, I don't care much for the rise quality an alu frame gives. Steel's still best.

Matt_S · Oct 6, 2006

Quote:

The 6000 and 7000 series' are commonly used aluminum alloys, so it's probably one of those. As others have mentioned, pure metals are rarely used in a structural application.

Quote:

for example if you take an aluminum bolt and put a 50% load on it, eventually it WILL fail

Click to expand...

. . . provided you cycle the load!

I was going to point out the same thing. Fatigue strength is a measure of how much load a piece can take for a given number of cycles. It tends to be much higher, though certainly not infinite, for steel, but certain aluminum alloys can come close. For the most part, however, that rule holds true.

1sttruck · Oct 6, 2006

For the same weight of steel you can get a larger cross section of aluminum in a frame, making it stiffer. It won't be as robust as steel with respect to repeated loading, so more inspection may be required. 2011 is a common aluminum 'aircraft alloy', but it's more prone to corrosion than say the 6000 to 7000 series. Aluminum is the primary material in most airplanes, one doesn't see many steel framed and steel skinned aircraft. One doesn't see many aluminum cars as they'd be more expensive, and less forgiving with the typical abuse and without the required regular inspections.

moribundman · Oct 6, 2006

I found a little more on the aluminum Audi uses, especially regarding fatigue testing, which is apparently extensive. Also, it seems that some of the aluminum alloys used are "short-fiber reinforced" (composites?). Self-piercing rivets are also increasingly being used in addition to laser MIG welding and pressure-injection-molded joint pieces.

The The Formula Palmer Audi Car sports a full aluminum honeycomb monocoque that meets all FIA F3 safety requirements.

benjamming · Oct 6, 2006

Quote:

Quote:

Click to expand...

The properties of a material, including its weaknesses, can be exploited. Shape, profile, alloys and how components interact is very complex. Working with aluminum is not easy, and the effort and time creating the ASF design took demonstrates that. When the Audi A8 first came out, one main concern was how to repair the frame, should it get bent in an accident. In '97 I talked to the guy who had the back then only body shop in northern California with the required equipment for repairing the ASF.

When aluminum frame mountain bikes (Kettler) came out, I got one. I ruined it within a week, and I broke the replacement bike just as quickly. It's not until now, more than 15 years later that I trust aluminum frames on MTBs. The materials, production methods and design have gotten a lot better. That said, I don't care much for the rise quality an alu frame gives. Steel's still best.

mori,
Not everyone can handle aluminum welding & many people still do not have a lot of faith in it. Case in point is the Honda 1800 Goldwing aluminum motorcyle frames that have had several problems. I can't remember exactly which aluminum alloy it is. Did the airline industry not give up welding that alloy back in the 1970s?

moribundman · Oct 6, 2006

Quote:

mori,
Not everyone can handle aluminum welding & many people still do not have a lot of faith in it.

Didn't I literally say working with alu was complex?

Need some help on Aluminum.

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