19 Aug 13
Originally posted by sonhouseDo you know why it is 30% lighter? Its atomic mass is only about 10% less. Are the atoms spaced further apart perhaps?
http://phys.org/news/2013-08-poisoning-corrosion-stainless-magnesium-closer.html
About 30% lighter than aluminum, this new metal can be a game changer for transportation of all kinds.
19 Aug 13
Originally posted by twhiteheadhttp://chemical-elements.findthedata.org/compare/2-53/Aluminum-vs-Magnesium
Do you know why it is 30% lighter? Its atomic mass is only about 10% less. Are the atoms spaced further apart perhaps?
Yes, the atomic radius is greater for Mg, which I would guess contributes to the fact that the density of solid Mg is 1.7g/cm^3 vs 2.7g/cm^3 for Al
19 Aug 13
Originally posted by humyThere are other considerations vis a vis composites vs metals.
This would never be the material of choice for construction in the far future because light-weight composite materials of multiwalled carbon nanotubes and resin/polymer would have vastly greater strength for both less weight and less volume.
If a composite breaks it often does so catastrophically. Metals might be more resilient and able to bend instead of breaking.
Of course with this new idea in magnesium, like aluminum, it starts out not being the strongest material around. Pure aluminum, elemental aluminum, sucks bigtime as a structural material. I found that out the hard way when I was charge with designing a small gas manifold. We had some pure aluminum hanging around and I thought I would give it a try. I actually succeeded but it was not fun trying to drill small holes and such in my design. I got the thing to work but you could dent the aluminum block with a fingernail, it was so soft. As it turned out, in my application, being soft wasn't a big deal as long as the device wasn't stepped on🙂
If I had to design it again, I would learn from that mistake and use a proper aluminum allow ten times stronger than the pure version.
I expect research to now pick up on this magnesium alloy and stronger versions will come out of it.
Look at the progress made with aluminum, which in the pure state can be bent by hand, you could bite the stuff in half with your teeth it is so soft but the material science guys have made the stuff now stronger than steel.
I expect the same from magnesium research.
19 Aug 13
Originally posted by sonhouse
There are other considerations vis a vis composites vs metals.
If a composite breaks it often does so catastrophically. Metals might be more resilient and able to bend instead of breaking.
Of course with this new idea in magnesium, like aluminum, it starts out not being the strongest material around. Pure aluminum, elemental aluminum, sucks bigtime a ...[text shortened]... uys have made the stuff now stronger than steel.
I expect the same from magnesium research.
If a composite breaks it often does so catastrophically. Metals might be more resilient and able to bend instead of breaking.
Arr but wait; I am not talking about any type of composite but rather just one type that gets all its strength from multi-walled carbon nanotubes, the material that has by far the greatest tensile strength of any known substance! I believe that, in the far future, ways would surely be found of making a composite so strong and reliable that it would never break unless very unnaturally massive load is placed on it.
20 Aug 13
quiOriginally posted by AThousandYoungI don't think that would be possible without quantum computers, present technology is way too slow, even the fastest of the fast. These computers would need to be millions of times faster than the fastest machines on the planet to come CLOSE to solving all the simulations required.
We can. Nobody who is wealthy enough to do that wants to spend the money.
20 Aug 13
Originally posted by sonhouseShould we invest in this and retire in a custom to which we are not accustomed?
http://phys.org/news/2013-08-poisoning-corrosion-stainless-magnesium-closer.html
About 30% lighter than aluminum, this new metal can be a game changer for transportation of all kinds.
20 Aug 13
Originally posted by humyhttp://www.sciencenews.org/view/generic/id/352497/description/Toylike_blocks_make_lightweight_strong_structuresIf a composite breaks it often does so catastrophically. Metals might be more resilient and able to bend instead of breaking.
Arr but wait; I am not talking about any type of composite but rather just one type that gets all its strength from multi-walled carbon nanotubes, the material that has by far the greatest tensile strength of any k ...[text shortened]... ong and reliable that it would never break unless very unnaturally massive load is placed on it.
Look at this report. Interesting.
20 Aug 13
Originally posted by sonhouseI wasn't talking about simulating it. I was talking about actually creating small amounts of alloys then running them through tests.
I don't think that would be possible without quantum computers, present technology is way too slow, even the fastest of the fast. These computers would need to be millions of times faster than the fastest machines on the planet to come CLOSE to solving all the simulations required.
You could for example create an alloy of magnesium with arsenic in a given proportion, role out sheets of of it, cut it into small pieces then test each piece for different properties such as electrical conductivity, magnetism, corrosion to different substances, strength, pliability etc.
Then repeat thousands of times for different proportions of magnesium and arsenic.
Then repeat for different metal combinations.
The article you linked suggests nobody had ever tested magnesium with small amounts of arsenic for corrosion.
20 Aug 13
1 edit
Originally posted by humyCatastrophic failure due to stress probably isn't the only consideration. Carbon burns readily which may rule out carbon nanotube based materials for some applications. Since an obvious application is in the exploitation of off planet resources, what are the properties of the two materials under solar radiation?If a composite breaks it often does so catastrophically. Metals might be more resilient and able to bend instead of breaking.
Arr but wait; I am not talking about any type of composite but rather just one type that gets all its strength from multi-walled carbon nanotubes, the material that has by far the greatest tensile strength of any k ...[text shortened]... ong and reliable that it would never break unless very unnaturally massive load is placed on it.
Originally posted by DeepThoughtthere are many different forms of carbon and they vary greatly in their combustibility. For example, soot generally burns very readily while diamond doesn't burn so readily although it can burn if it gets hot enough. It just so happens that carbon in the form of a solid mass of multi-walled carbon nanotubes are one of the most fire resistant forms of carbon. In addition, I am not talking about pure carbon here but rather a composite material of multi-walled carbon nanotubes embedded in another substance that helps to 'glue' the fibers together such as a polymer or some similar substance. Where fire is an issue, that other substance can be a none combustible fire resistant substance such as a silicon compound thus making the whole composite material fire proof.
Catastrophic failure due to stress probably isn't the only consideration. Carbon burns readily which may rule out carbon nanotube based materials for some applications. Since an obvious application is in the exploitation of off planet resources, what are the properties of the two materials under solar radiation?
(sorry, I don't know the answer to your question )