4 ms·

So does this mean that at the macroscale, the 3D-printed metal will be 3x as strong? Could this result in a car that's 1/3rd the metal weight? (I'm guessing "n

So does this mean that at the macroscale, the 3D-printed metal will be 3x as strong? Could this result in a car that's 1/3rd the metal weight? (I'm guessing "no", but I want to understand why.)

hutzlibu 3y ago
I am guessing yes. It just would be really, really slow and expensive to build, so you might as well switch to something more cheap, like diamonds.. Edit: but it is not clear to me, whether this technic can be applied to macroscopical objects at all, or if you would have to do it in steps - and then have structural weaknesses at the connection points.
zweifuss 3y ago
It probably needs several military applications first. For example, you very rarely see transparent aluminum (also known as ALON®) in windows 30 years after its invention, but we wouldn't even be making it, for example for IR missile domes, if its development hadn't been funded by the U.S. Department of Defense. The next step would then be special medical applications. For example, as a synthetic material for implants. And there you wouldn't want ultra strength, but a certain bounciness and relatively low density.
xeonmc 3y ago
I'm guessing that the UTS would be the same, it just moves up the yield strength to be closer to UTS.
rsfern 3y ago
In principle, I think so, but there a lot of technical barriers to learning how to actually make the structures you’d need to do it. (I haven’t read the actual paper because of the paywall) From my understanding, there are (at least) 3 factors responsible for the high strength - nanoscale geometry, basically the can 3D print nanoscale truss structures - nanocrystalline base metal. There are established methods for fabricating bulk nanocrystalline metals [0], but doing it in an additive manufacturing process at bulk scale I think is a totally open question - they’re getting extra strength from residual porosity in the metal grains (the pores pin dislocations, stopping one of the principal deformation mechanisms [1]). This is a well known phenomenon, but getting uniform nanoscale pore structure sounds really hard, especially in a bulk metal, and extra especially in an additive setting 0: https://en.m.wikipedia.org/wiki/Nanocrystalline_material# https://en.m.wikipedia.org/wiki/Nanocrystalline_material# 1: https://en.m.wikipedia.org/wiki/Dislocation https://en.m.wikipedia.org/wiki/Dislocation 1b: https://en.m.wikipedia.org/wiki/Zener_pinning https://en.m.wikipedia.org/wiki/Zener_pinning

So does this mean that at the macroscale, the 3D-printed metal will be 3x as strong? Could this result in a car that's 1/3rd the metal weight? (I'm guessing "no", but I want to understand why.)

hutzlibu 3y ago

I am guessing yes. It just would be really, really slow and expensive to build, so you might as well switch to something more cheap, like diamonds.. Edit: but it is not clear to me, whether this technic can be applied to macroscopical objects at all, or if you would have to do it in steps - and then have structural weaknesses at the connection points.

zweifuss 3y ago

It probably needs several military applications first. For example, you very rarely see transparent aluminum (also known as ALON®) in windows 30 years after its invention, but we wouldn't even be making it, for example for IR missile domes, if its development hadn't been funded by the U.S. Department of Defense. The next step would then be special medical applications. For example, as a synthetic material for implants. And there you wouldn't want ultra strength, but a certain bounciness and relatively low density.

xeonmc 3y ago

I'm guessing that the UTS would be the same, it just moves up the yield strength to be closer to UTS.

rsfern 3y ago

In principle, I think so, but there a lot of technical barriers to learning how to actually make the structures you’d need to do it. (I haven’t read the actual paper because of the paywall) From my understanding, there are (at least) 3 factors responsible for the high strength - nanoscale geometry, basically the can 3D print nanoscale truss structures - nanocrystalline base metal. There are established methods for fabricating bulk nanocrystalline metals [0], but doing it in an additive manufacturing process at bulk scale I think is a totally open question - they’re getting extra strength from residual porosity in the metal grains (the pores pin dislocations, stopping one of the principal deformation mechanisms [1]). This is a well known phenomenon, but getting uniform nanoscale pore structure sounds really hard, especially in a bulk metal, and extra especially in an additive setting 0: https://en.m.wikipedia.org/wiki/Nanocrystalline_material# https://en.m.wikipedia.org/wiki/Nanocrystalline_material# 1: https://en.m.wikipedia.org/wiki/Dislocation https://en.m.wikipedia.org/wiki/Dislocation 1b: https://en.m.wikipedia.org/wiki/Zener_pinning https://en.m.wikipedia.org/wiki/Zener_pinning