determing material

Date 02-24-2004 13:50

Using Table 6.1.9, published in "Marks Standard Handbook for Mechanical Engineers, 10th edition, here are some numbers that may help:

Aluminum has a density of approximately 175 lb/cubic feet
Magnesium has a density of 111 lb/cubic feet

Cut equal size pieces from the material you are interested in, and from a piece you know to be aluminum. If the weights are equal (or very close) you may assume the material is aluminum. If magnesium, the piece will be about 2/3 the weight of the aluminum piece.

I hope this helps. If someone has a better method, I would be interested in knowing it.

Charles Hall

By bmaas1

Date 02-24-2004 14:22

I'm trying to remember years ago when I welded a lawnmower deck( I believe it was a lawnboy) with TIG it would have a blueish type of color to the arc if it was magnesium. I may be way off on this.

Brian J. Maas

By jsuder Date 02-25-2004 04:41

I found some info out from the local welding supply. Place a small amount of silver nitrate on the material in question then add a drop of water to it, if it turns black it's magnesium if it remains clear, then it's aluminum.

By 357max

Date 02-25-2004 22:08

Aluminum's GTAW arc should be white. Magnesium should be green. If you have zinc die cast (pot metal, white metal) that should be a violet/purple arc. Now the only thing to determine is the alloy. Aluminum with high amount of magnesium will show a greener arc than white.