NightHawkInLight Posted July 14, 2011 Posted July 14, 2011 It probably does contain quite a bit more oxide than mgal that is cooled into one solid ingot would. The reason being that the mgal is exposed to the air and water while still very hot and reactive, whereas an ingot cooled inside a crucible with very little air, and far less exposed surface area would build up much less oxide prior to milling. The additional oxide may or may not be of any noticeable consequence in compositions, but I suspect it's there. As far as the crystal structure and that goes, I know enough about metallurgy to know that I don't know enough about metallurgy. Just a guess, but I would bet that water quenched mgal is more brittle than air cooled because the quick cooling wouldn't allow the time for a stable and consistent crystal structure to form. As with any crystal growth, it seems that rate of formation would relate directly to size and structure. Again, that may or may not be noticeable in the milling or use in compositions.
50AE Posted July 14, 2011 Posted July 14, 2011 A friend of mine is frequently milling magnesium powder, remotely.He told me he decided to do a test one day.He almost emptied his jar, letting his stainless steel media milling dry with a very little Mg powder between them."I was sure it was going to explode" he said. "But I did it from curiosity. I started my ball mill remotely and I waited, doing some other work" Then after a few minutes, he said he heard a slight BOOM. He went to check his ball mill to see the PVC endcaps blown and shattered, but the drum and media were ok, as was the ball mill.
NightHawkInLight Posted July 14, 2011 Posted July 14, 2011 As I've mentioned here before, I personally know someone who was hospitalized for a number of days after a coffee mill full of mgal powder exploded in his face. You need to be very careful milling reactive metals in the presence of oxygen.
Bonny Posted July 15, 2011 Posted July 15, 2011 (edited) I just was at a loss and misspelled it. Got a little worked up about the welding helmet eh? Edited July 15, 2011 by Bonny
dagabu Posted July 15, 2011 Posted July 15, 2011 Got a little worked up about the welding helmet eh? But I like my Selstrom!
Bonny Posted July 16, 2011 Posted July 16, 2011 (edited) But I like my Selstrom! I use a Selstrom too, but not a (wussy) auto dark type Edited July 16, 2011 by Bonny
Bilbobaker Posted July 16, 2011 Posted July 16, 2011 Excellent idea on the water quenching. Most any metal will crumble easily of cooled too fast from a molten state.
dagabu Posted July 16, 2011 Posted July 16, 2011 I use a Selstrom too, but not a (wussy) auto dark type Auto-darkening and battery free to boot! -dag
oldguy Posted July 17, 2011 Author Posted July 17, 2011 Auto-darkening and battery free to boot!-dag True, Mg & Al gets a little darker when you alloy them togather.But, how do you install the battery in it, once water quenched, blended & screened.Do you put it in the ball mill?
dagabu Posted July 17, 2011 Posted July 17, 2011 True, Mg & Al gets a little darker when you alloy them togather.But, how do you install the battery in it, once water quenched, blended & screened.Do you put it in the ball mill? Smarty-pants! -dag
guntoteninfadel Posted July 21, 2011 Posted July 21, 2011 And I thought makin black powder was a job! I know its more expensive but for the time saved and the lack of "infernos" I think I am going to stick with buying it!
oldguy Posted July 21, 2011 Author Posted July 21, 2011 And I thought makin black powder was a job! I know its more expensive but for the time saved and the lack of "infernos" I think I am going to stick with buying it! A few “inferno’s” in life, is what makes it exciting. Lesson learned was, don’t add antimony trisulfide to the mix. But, often idea’s come from bad lessons learned. Water quenching molten mgal creates a thin popcorn like material that is both quickly & easily reduced to small sized particles of about any mesh size you want. With a high quality blender, you can quickly reduce it so fine, there is little, if any need for ball milling. What comes to mind is how to achieve equivalent mgal properties without water quenching it. I imagine foaming molten mgal would effectively accomplish the task. http://en.wikipedia.org/wiki/Metal_foam Certainly, foaming metal is not something the average Joe would do. Because of the equipment required. But, the process is simple, straight forward and not expensive, if one had the equipment.
Givat Posted August 1, 2011 Posted August 1, 2011 Great idea Oldguy!tried it today with 1 kilo magnalium.the magnalium came out more brittle then usual I think. the water barrel:http://i1111.photobucket.com/albums/h479/questl/MgAl/watervessel.jpg the product:http://i1111.photobucket.com/albums/h479/questl/MgAl/1kiloMgAl.jpghttp://i1111.photobucket.com/albums/h479/questl/MgAl/MgAl.jpg I let it dry for about 4 hours and crushed it more with meat grinder.
oldguy Posted August 1, 2011 Author Posted August 1, 2011 Great idea Oldguy!tried it today with 1 kilo magnalium.the magnalium came out more brittle then usual I think. It was a surprise to me also how brittle it when water quenched.Being that brittle makes it VERY easy to reduce to fines.
Bonny Posted August 1, 2011 Posted August 1, 2011 Can't wait to try it!! I've always found MgAl nice and easy to break up, but to make it even easier is awesome!
50AE Posted August 2, 2011 Posted August 2, 2011 I remember my first time, I was so excited breaking the pop corns with my hands. Afterwards of course, my skin was a little cut, but I enjoyed it anyway
oldguy Posted August 2, 2011 Author Posted August 2, 2011 8 gallon stock pot the molten mgal was poured into.Once cooled, I ran a hose in it to clear the water.Then poured off most of the water.Simple to use any hammer or blunt heavy object to crush the mgal while still in the water.Only took about 30 or 40 seconds to reduce it all very small while still in the water.After drying, I used a remote control stainless blender to reduce it further.
oldguy Posted August 2, 2011 Author Posted August 2, 2011 (edited) Magnesium wheelsScore @ garage sale $25One is damaged from running on a flat tire. 68 lbs total weightSeems a shame to cut them up.But, thats life & I would rather have the mgal. Edited August 2, 2011 by oldguy
oldguy Posted August 2, 2011 Author Posted August 2, 2011 Cutting aluminum molding, cooling fins, etc down to crucible size is easy with a skill or chop saw & metal cutting blade.
50AE Posted September 7, 2011 Posted September 7, 2011 I got very familiar with this beast.I made 3kg of MgAl today. The stuff burns only while floating on the water. It hungers to get the water in a vapor state. But when it sinks, it extinguishes. So while pouring MgAl, have a rod next to you to quickly submerge stubborn floating and burning particles. It's scary though. If you don't have a rod, you will witness a powerful propagation of the MgAl flame.
dagabu Posted September 7, 2011 Posted September 7, 2011 I got very familiar with this beast.I made 3kg of MgAl today. The stuff burns only while floating on the water. It hungers to get the water in a vapor state. But when it sinks, it extinguishes. So while pouring MgAl, have a rod next to you to quickly submerge stubborn floating and burning particles. It's scary though. If you don't have a rod, you will witness a powerful propagation of the MgAl flame. I have not had any flame from the flow when quenching, only once when I had the lid off and before I put a layer of charcoal did I have any flame. -dag
Recommended Posts