Sciencemadness Discussion Board

Magnesium & Aluminum turnings, filings & chips - which alloys are acceptable?

RogueRose - 23-1-2016 at 16:33

I've had a difficult time finding Mg or Al in pure form anywhere as it is all some kind of an alloy, even if it is 95-97 Al or Mg (for the higher Al/Mg percentages). There are so many different alloys of Al that I'm wondering when Al powders are purchased whether it is of an alloy or if it is 100% Al.

Does anyone know if there are any acceptable alloys for either Al or Mg? Any idea what aluminum foil composition is, or soda cans?

blogfast25 - 23-1-2016 at 17:09

https://en.wikipedia.org/wiki/7068_aluminium_alloy

Scroll down for an extensive list of Al alloys.

Morgan - 23-1-2016 at 17:22

This might be acceptable.
"This listing is for one pure magnesium ingot (99.9%) weighing approximately 1lb. This item is manufactured in the United States, and is delivered with a certificate of analysis."
http://www.ebay.com/itm/Magnesium-Metal-Ingot-99-9-Pure-1lb-...

"These 99.95% minimum guaranteed. Pure magnesium metal ingots are quite impressive. We have these materials in just about any form and quantity that you might be seeking, from shavings to metric tons. This listing is for one ingot that weighs about 16-18 pounds (typically between 16 and 17 pounds) and measures about L 21.5" x W 5.75" (base)/W 4.25" (top) x H 2.75". This will be shipped by FedEx Ground. We now allow international orders on this item. It will be shipped by USPS International Priority Mail Flat Rate."
http://www.ebay.com/itm/Magnesium-Metal-Ingot-Large-99-95-Pu...

[Edited on 24-1-2016 by Morgan]

Sulaiman - 23-1-2016 at 23:32

Since about 80% of magnesium production is from China, eBay is your best bet.
For my electrochemistry experiments I bought magnesium

powder, 99.8%
ribbon, 99,95%
rod, 99.99%

of course by the time that you receive it there will be some surface oxidation,
the rods were oiled and clingwrapped, very little visible oxidation, but not shiny,
the most visibly oxidised was the ribbon edges,
the powder is grey, not shiny, so must also be oxidised somewhat.
So if you count oxides, it is probably very difficult to get high purity,
cutting the middle out of rods would probably be best, but I've only got two so I shall not try.

99.8% aluminium on eBay but I can't think of anything domestic that is pure aluminium
maybe cooking foil that does not include recycled aluminium,
which would contain magnesium from drink can tops.

careysub - 24-1-2016 at 15:39

Aluminum foil is almost all 1235 alloy which is 99.35% aluminum. This is pretty much guaranteed because the aluminum does not roll out into a foil as easily if it has a higher alloy content, and this one alloy is produced in huge amounts for this purpose. Grocery foil is optimized for cheap production.

There are higher alloy foils that have greater strength that are used in manufacturing, but you won't find them on a roll in your grocery store.

[Edited on 24-1-2016 by careysub]

MrHomeScientist - 25-1-2016 at 07:59

Quote: Originally posted by RogueRose  

Does anyone know if there are any acceptable alloys for either Al or Mg? Any idea what aluminum foil composition is, or soda cans?

Define "acceptable." Your intended use dictates the grade of aluminum you need.

According to several people in this thread, soda cans use alloys in the 3000 series for the body and alloys from the 5000 series for the ends. I think actually the bottom is the same as the walls, and only the lid uses the 5000 alloy. The 3000 series are alloyed with about 1% manganese, and the 5000 are alloyed with around 5% of magnesium. There's a nice table here.

UC235 - 25-1-2016 at 21:57

All commercially purchased metal is going to be named as an alloy. Consider alloy series 11XX aluminum. These are substantially pure aluminum metal. The alloy number designates the acceptable levels of other metals not removed in refining. Alloy 1100 is min. 99% Al up to 99.5%. Alloy 1199 is 99.99% which is excellent purity.

Unfortunately you are very unlikely to see 11XX series aluminum for sale anywhere common because it is mechanically weak.

As mentioned above, aluminum foil is an alloy but the drug cooks seem to have made it work fine in application as mercury amalgam at least.

For magnesium I suggest buying turnings from galliumsource or somewhere similar. Pure magnesium isn't used in consumer applications. The few places it is used tend to be alloyed with aluminum to give more favorable mechanical properties. They do sell small blocks as a mediocre firestarter to be lit with a flint and steel but the cost would be quite high compared to just buying bulk turnings.