[HN Gopher] 3D printed titanium structure shows supernatural str...
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       3D printed titanium structure shows supernatural strength
        
       Author : gmays
       Score  : 60 points
       Date   : 2024-03-03 16:54 UTC (6 hours ago)
        
 (HTM) web link (www.rmit.edu.au)
 (TXT) w3m dump (www.rmit.edu.au)
        
       | SubiculumCode wrote:
       | Rockets of the future
        
       | LegitShady wrote:
       | cool now perform a repair on something inside of it.
        
         | eastbound wrote:
         | Can you repair your hairdryer? It's literally a Chinese motor
         | with a Chinese resistor, the two most frequent objects in the
         | world.
         | 
         | Objects in the industrial world can't be repaired. But Titanium
         | can be melted.
        
           | justinclift wrote:
           | > Objects in the industrial world can't be repaired.
           | 
           | That makes no sense to me, as industrial things commonly
           | _are_ repaired. Sometimes many times across decades as one
           | part or other wears.
        
             | almostnormal wrote:
             | From a certain point of view repairing is fixing things
             | that are literally broken, which involves glueing, welding,
             | screwing, ...
             | 
             | Replacing parts is not repairing from that point of view,
             | even if at a macroscopic level it returns something back to
             | working condition.
        
           | TaylorAlexander wrote:
           | > Can you repair your hairdryer? It's literally a Chinese
           | motor with a Chinese resistor, the two most frequent objects
           | in the world.
           | 
           | Most hair dryers don't come with parts manuals so we wouldn't
           | know exactly which replacement part to get. And there's more
           | to it like a switch, a cord, etc. These things could be
           | designed for repair but they would have to provide reliable
           | part numbers for the internals, which they currently do not
           | do.
           | 
           | > Objects in the industrial world can't be repaired.
           | 
           | Objects in the industrial world most certainly can be
           | repaired and it happens all the time. For example here is how
           | a giant excavator tire is repaired:
           | 
           | https://youtu.be/p0R-YWQCfdQ?si=iGagfyttgO5vTvDr
        
         | PeterisP wrote:
         | How do you perform repair on something inside a solid steel,
         | titanium or aluminum block, which is what this structure
         | replaces?
         | 
         | These are structural components that don't have anything
         | "inside" but are used as material for carrying/distributing
         | loads, and their strength and weight is the thing that matters.
         | If their integrity is compromised, you generally don't repair
         | structural components if the repaired seam wouldn't have the
         | same strength as the original material, but replace them.
        
           | spectaclepiece wrote:
           | Do you think there will be a market for typical household
           | electronics items such as the hairdryer specifically made
           | with repairability in the near future? Perhaps driven
           | (unlikely) by consumer demand or more likely by resource
           | prices or legislative pressure.
        
           | 13of40 wrote:
           | I think a real-life example that might illustrate the
           | difference is a car that's been in an accident. A good body
           | shop can do a lot as far as straightening components, doing
           | new spot-welding, etc. in a car that's made with contemporary
           | techniques, but imagine if it had a chassis or unibody
           | components made out of this material. They would need to be
           | replaced, because straightening won't repair the micro-
           | structure, and they probably can't be welded. Replacement is
           | going to be far costlier as well, because you'd have to
           | disassemble the whole car and put it back together. plus the
           | replacement part has to be meticulously 3D printed instead of
           | stamped/forged/welded.
           | 
           | That said, I can imagine it being good for applications like
           | fighter jet components where it's probably considered scrap
           | after the first accident.
        
         | iancmceachern wrote:
         | That's like saying, cool, now make a repair of a small Crack in
         | the middle of the center later of a sheet metal panel.
         | 
         | There is no need to do so. You would replace the part.
        
       | ethagknight wrote:
       | It would make sense that a complex structure that mimics the
       | molecular structure would be stronger per unit of mass than a
       | lump of the same material, in the same way that a simple i-beam
       | or a truss is stronger that a solid rod of steel in specific
       | design applications. In both cases, its strength where you need
       | it; nothing where you don't
       | 
       | Really neat stuff.
        
         | goodSteveramos wrote:
         | Do you think this team invented that idea? Im struggling to
         | understand how large their contribution is.
        
       | goodSteveramos wrote:
       | The author seems to confuse what an alloy is with the shape of a
       | metal part. The alloy is the chemical composition, the shape is
       | just the shape. The basis of comparison is likewise flawed. It
       | seems like they compare their shape printed in titanium to a
       | solid block of magnesium, but they should really compare it to
       | the best known titanium lattice as that would show how much of an
       | improvement their design is. For all we know their design is
       | worse than the existing state of the art
        
         | zokier wrote:
         | The article has whole section called "2.3 Comparison with
         | Existing Metal Lattices"
        
       | gimmeThaBeet wrote:
       | At first with the kerning on my screen I was wondering why MIT
       | had an Australian TLD.
       | 
       | They seem most interested in the thin band running through the
       | lattice, my curiosity is how well can the 3D printer make that
       | consistently? I would assume it's contribution to strength might
       | be pretty significant, and might be quite non-linear with any
       | variance.
       | 
       | A common frustration I've had with 3d printing is even keeping
       | within specs on thin planes and walls can turn out suboptimally,
       | but maybe thats some bike shedding, I'm ceratinly not doing
       | anything in metal.
        
         | rawfan wrote:
         | Those industrial titanium powder printers are not comparable at
         | all what you know, I assume. They're used at scale to produce
         | airplane parts. Usually also utilising bionic structures, e.g.
         | to make brackets that are much lighter and sturdier, than their
         | conventional counterparts.
        
       | larsrc wrote:
       | Are these properties unique to printing in titanium? Doesn't
       | sound like it. So hopefully we will see this as an infill option
       | soon.
        
         | Animats wrote:
         | Right. This should be helpful for all 3D printing. Finite
         | element analysis on infill patterns looks like it helps.
         | 
         | This pattern looks like it's designed for an isotropic
         | material. Sintered metal printers ought to produce solid metal.
         | Extrusion printers, though, tend to have weaker inter-layer
         | bonds than bonds within the layer. So this may not work as well
         | in PLA. Might need a pattern that compensates for the weaker
         | inter-layer bonds.
        
           | jayyhu wrote:
           | Also helpful for Stereolithographic printers (SLA/DLP/LCD),
           | since they also don't have inter-layer adhesion issues like
           | extrusion printers.
        
           | interstice wrote:
           | Recently saw an interesting infill/layer pattern that offset
           | the layers and spaced them (think hexagonal pattern when
           | viewed from the side) - might help with the single plane
           | delaminating issue. Combined with this style of infill
           | pattern we could be getting somewhere.
           | 
           | Makes me wish I had time to mess around with GCODE
        
             | krasin wrote:
             | This sounds a lot like "brick layers" by CNC Kitchen:
             | https://www.youtube.com/watch?v=5hGm6cubFVs - I believe
             | that something like that will be a must for future 3d
             | printing slicers, as it increases mechanical strength with
             | no extra hardware needed.
        
         | thfuran wrote:
         | No, I know I've read an article about 3d printed steels being
         | stronger if arranged _just so_.
         | 
         | Edit: it was probably about
         | https://www.science.org/content/article/3d-printing-doubles-...
         | 
         | It looks like there might be enough difference in relevant
         | scale that both techniques could be applied.
        
       | OvbiousError wrote:
       | The hollow struts are interesting, I've worked with lattices but
       | that's not something I saw before. I guess they are stronger than
       | solid struts with a smaller diameter so they have the same amount
       | of material.
        
         | TaylorAlexander wrote:
         | I'm very curious if they can actually empty the un-fused
         | material out of those tiny struts. They said they printed it
         | with a powder bed printer, so voids would be filled with powder
         | unless they can be emptied. I'm curious how that affects
         | weight. I wonder if they used the theoretical empty weight or
         | the actual manufactured weight in their calculations, and how
         | different that makes things.
        
       | passwordoops wrote:
       | This is awesome, but did they really need to use "supernatural"?
       | There's an explanation for the strength using the laws of physics
       | (or, dare I say, Nature) ergo it is not "supernatural"
        
         | mym1990 wrote:
         | If the outcome is stronger than what would be found in nature,
         | I would find this to be "supernatural". Of course the term
         | could get watered down as anything manipulated and altered by
         | human or machine could be deemed supernatural I guess.
        
           | thfuran wrote:
           | But elemental titanium doesn't occur in nature in the first
           | place, so the straining of terminology seems ill-founded
           | unless we want to call my titanium spoon supernatural as
           | well.
        
             | blagie wrote:
             | I do.
             | 
             | https://www.youtube.com/watch?v=XO0pcWxcROI
        
           | CyberDildonics wrote:
           | In your real life then, would you tell someone to their face
           | that an aluminum can is "supernaturally" strong?
        
           | anigbrowl wrote:
           | We already have 'artificial' for this.
        
       | blagie wrote:
       | This is step 0.
       | 
       | I suspect the real power will come in with composites. Even with
       | metals, metal matrix can have very nice properties
       | (https://en.wikipedia.org/wiki/Metal_matrix_composite) compared
       | to a base metal.
       | 
       | The key thing of interest here, to me, are the holes. The holes
       | can be filled with something other than air.
        
         | DanHulton wrote:
         | Wouldn't that just raise the density of the structure and
         | defeat the purpose?
        
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       (page generated 2024-03-03 23:00 UTC)