Fuchs are mostly Magnesium

[SC-targa]

Originally posted by banjomike
Paul Frere refers to some cast Al wheels with a high Si content introduced in '73. I don't belive I have ever seen these. What do they look like? Are they the 914 wheels?

The Si is added to improve the flow of the molten metal during the casting process. Even when aluminum is juiced up with lots of Silicon, it still can't be cast into such intricate shapes as magnesium, which is phenominal.

regarding designation of Magnesium alloys...No classification system for magnesium alloys has international acceptance. That of the American Society for Testing Materials (ASTM) is the most widely used. In this system, the first two letters indicate the principal alloying elements as shown in the table below. The letter corresponding to the element present in the greatest quantity is used first; if they are equal, they are listed alphabetically. The letters are followed by numbers which represent the nominal compositions of the principal alloying elements in weight% rounded to the nearest whole number; thus AZ91 means the alloy Mg-9Al-1Zn.

Regards,

Jerry Kroeger

[89911]

Originally posted by nick-moss
From that web address above

Metal Polishing Myths, Half Truths and Lies
21. All metals can be polished

Not to make them shine they can't.

There are some people out there that say they have a mag and aluminum polish. Well magnesium doesn't shine. Not bright anyway. It's a white metal. You can clean it. You can remove oxidization, But you can't polish it! In mag alloys it depends on the amount of magnesium content as to how well it shines.

I'm not sure what the % of Magnesium is in the fan blade, but is can easily be polished to a mirror finish. It soon turns into the matte finish withing a month or so. Still better then the dirty intial look. The fuchs finish last for months. In fact is doesn't change much over the course of a year. It just looses some of that "chrome" finish look that comes after initial polishing.

[GDSOB]

Anyone have access to a mass spectrometer? That will settle it!

[ChrisBennet]

Originally posted by Wayne at Pelican Parts
Hmm, I thought someone would have been able to come up with a definitive answer by now...

-Wayne

Where is T*d when you need him?
-Chris

[JTO]

Hey guys,

Magnesium burns pretty easily (you can light finely divided powder or ribbon with a match). Lets sacrafice a Fuch, scrape a pile of the metal onto a surface, and try to light it?

Good idea, eh?

Troy

[jwetering]

I have acces to a ICAP /MS - for those not in the know that's an Inductively Coupled Argon Plasma / Mass Spectrometer.

It migh take a while, but eventually I promise I will shave a hair off of the back of one of my Fuchs and submit it for analysis.

I also have a XRF (X-Ray Fluorescence Spectrometer) in my own lab here, but I'm not sure I can grab enough sample from the back of a wheel to make a decent measurement.

What would be easier though is for someone to find a copy of: ASTM A01.91 - E527-83(2003) Standard Practice for Numbering Metals and Alloys (UNS) and look up AS10.62

That said...the Euros might use their own standard for naming alloys. Contrary to popular belief, North America does not set the standard for the entire world (do I have to bring up the metric system).

I'll get to that little metalurgical experiment by the end of the year I hope.

[Randy Webb]

That's great! I can think up lots more projects for you....

I'd bet there's a DIN std. on that, but who knows maybe its ref'd in the ASTM docs.

So, what do you do? I take it youare an anal. chemist?
(I am a biologist but also have a chem degree and have been known to hang out on the other side of the RR tracks).
- Randy

[DanS911]

Meantime while we wait for Jasper to give the specs... what is the best way to peep the shine on a set of polished Fuchs? Mine were polished almost a year and always looked great until I had the brilliant idea to polish them again myself :-( now in about a week they look dull! Wax?? what kind of wax on bear metal, be it Aluminum or Magnesium?
BTW I used Mothers Mag and Aluminum Polish

[Jens]

Paul Frere, Porsche PET, Factory manuals, Factory Parts Lists, and on and on...differentiate aluminum (Fuchs) and magnesium,pressure casting (Mahle) with all the pertinent Part numbers. I researched this all a while ago in a go-round with a respected colleague who insisted that the Mahle Gas Burners were NOT magnesium. After presenting him with all the reference bibliography, he just har-r-r-rumphed and insisted all my soueces were WRONG! Heh-heh. A matter of pride at that point I guess. He never offered any substantiation of his claim.

Jens

[Jens]

oops, that is *sources* not soueces. The reading is all out there (and on my shelves), but it would be great to find out the exact mix in the alloys. By the way, aluminum shavings/filings burn very well indeed, don't ask *how* I know, but I know.

Jens

[JTO]

Jasper and Randy,

We don't need a MS or ICP. All that needs to be done is that a sample of Fuch metal be taken up in sulfuric or hydrochloric acid and shot it on a graphite furnace AA or flame AA. We can quantify the magnesium and aluminum easy enough. I won't sacrifice my Fuchs, but maybe Jasper can do this anaylsis.

Although I too am an analytical chemist, I no longer work in an analytical laboratory so I can't easily do the testing.

Troy

[masraum]

My fuchs taste much more like aluminum ("aluminium" for you Brits) than magnesium!

[island911]

AlMgSil or AA6082*; Al 0.9Mg 1.0Si 0.7Mn

edit: those are % . .. .w/ the balance in Al.
(read: "Fuchs are predominantly Magnesium" is total BS . . . though the confident manner sure was convincing )

*per Excellence article on Fuchs, pg 107, issue#93

[JTO]

Yea Jens, but Al is much harder to ignite than Mg. You can't light Al with a match.

Troy

[Wayne 962]

Where's Warren when you need him anyways...

-Wayne

[jwetering]

take it youare an anal. chemist?

Well, I get a little picky once in a while maybe...but anal is a bit harsh



I figure ICP or ICP/MS is the way to go so we can get the whole list of metals. The GFAAS I'm familiar with is kind of a one element at a time intrument.

What's with your post Island ? Maybe it's me but it doesn't seem clear.

So if Island doesn't come through with a reliable reference then I figure a 0.05 gram sample in 50 mL hydrochloric/nitric acid solution will give us what we need to know. Give me a couple of weeks. I've got a xmas coming up and I have to take my wheel off anyway to have new rubber mounted

[island911]

"not clear" Hmmm, okay. . .

Excellence article on Fuchs, (issue#93 pg 107) says the alloy used to make Fuchs is "AlMgSil or AA6082."

AA6082 is; Al 0.9Mg 1.0Si 0.7Mn

--OR--
0.9% Mg (Magnesium)
1.0% Si (Silicon)
0.7% Mn (Maganese)
97.4% Al (Aluminum) [implied balance]

Therefore; the original assertion of this thread "Fuchs are predominantly Magnesium" is total BS.

[dvkk]

OK, so why is the wheel marked with AS10.62, a magnesium alloy specification?

[nick-moss]

I have 5.5" Fuchs marked AS1.08

[mb911]

Ok

Its time for me to pipe up.

Fuchs are a magnesium-Silicon aluminum alloy Which would make it fall in the 6 series aluminums. They weld excellent and can be repaired very easily with your standard TIG rod not a fancy Mag rod. I KNOW this as this is covered in my classes at the local college where I teach welding and metal science. As for polishing Magnesium will polish but will fade quickly and gray out or marblize to its natural state. I have a set of fully polished 6X15s that have not had any up keep for a year and they still look great. Just really my thoughts good luck with the debate

Ben

77 911 3.0
75 914-6 2.7