[HN Gopher] How to 3D-Print One of the Strongest Stainless Steels
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How to 3D-Print One of the Strongest Stainless Steels
Author : sizzle
Score : 62 points
Date : 2022-09-26 17:49 UTC (5 hours ago)
(HTM) web link (www.nist.gov)
(TXT) w3m dump (www.nist.gov)
| SV_BubbleTime wrote:
| An annoyance, but if they're heat treating in the printing
| step... that's 17-4 steel, but it will never be 17-4 PH, as there
| is no perception hardening step.
|
| Also, "one of" should be emphasized there. 17-4 is very good
| common steel. But there are tons like inconel (a tradename for a
| 600 series), or maraging steels that beat in strength
| applications. It's good, but it's common good. Not common great.
| And certainly not exotic good.
|
| As a machinist, you had better have a good plan before get into
| inconel. For 17-4, you can pretty much just have at it.
| kansface wrote:
| This isn't my area of expertise. The article mentioned that
| they could skip some sort of tempering/annealing step. Is that
| distinct from the PH step here?
| adrian_b wrote:
| Non-pay-walled version of the research paper:
|
| https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=93265...
| bozhark wrote:
| 2nd page of the paper has a decent description with data and a
| visual diagram of the process, it's worth checking out.
|
| "Characterization of phase transformation dynamics of
| commercial additively manufactured 17-4 stainless steel
| (C_17-4) during laser melting. (a) Schematic illustration of
| in-situ laser-melting X-ray diffraction experiment. A vertical
| laser beam scans the sample to create a localized melt pool.
| The micro-focused high-energy X-ray beam is used to probe the
| phase transformation dynamics with a frame rate of 250 Hz. (b)
| Room temperature XRD pattern of as-solidified C_17-4 after
| laser melting. (c) XRD intensity map (XRD peak intensity
| evolution as a function of time) during laser melting of C_17-4
| from 0 s to 20 s. The liquid gap near 0.15 s without any
| diffraction peaks denotes the period when all the material in
| the X-ray path was fully melted. The time axis is enlarged in
| the 0-1 s range to highlight the phase transformation details
| during the initial solidification stage. (d) EBSD of as-printed
| C_17-4 microstructure displayed in inversed pole figure (IPF)
| coloring. (e) EBSD of as-printed C_17-4 microstructure
| displayed in image quality (IQ) map. Martensite (a') phase and
| a mixture of austenite (g) and d-ferrite (d) phases were
| pointed out in the microstructure. (f) EBSD phase map of as-
| printed C_17-4. (g) XRD intensity evolution from (c) during
| solidification. The time axis is enlarged in the 0-1 s range.
| The uncertainty for BCC intensity measurement is 1 %. The
| uncertainty for FCC intensity measurement is 2 %."
| abdullahkhalids wrote:
| Anyone have a rough idea of how much such a printer would cost?
| ezekg wrote:
| A direct metal laser sintering (DMLS) machine costs >$100k.
|
| Maybe someday it'll be as affordable as FDM is now.
| abdullahkhalids wrote:
| That doesn't sound too expensive, given the temperatures and
| safety features involved.
|
| But the raw parts are probably an order of magnitude cheaper,
| so price should come down to those levels if production
| scales up.
| TOMDM wrote:
| Are there any pictures of a finished part?
|
| I'm assuming there would be features that need to be cleaned up
| after a print, but this looks incredible.
|
| I wonder what the cost savings are like vs a 6dof CNC mill for
| parts that can be made that way.
| SV_BubbleTime wrote:
| >6dof CNC mill
|
| 6-axis, dof is the wrong term here.
| defterGoose wrote:
| 5-axis. No one uses Stanford arms for milling strong
| materials. The sixth axis would be redundant with the spindle
| rotation anyway.
| monkpit wrote:
| Not only that, but if you can print finished parts you can
| engineer parts that cannot be physically machined.
| TOMDM wrote:
| Yeah, the ability to rapid prototype parts with occluded
| cavities that can't be machined by a CNC makes this a
| compelling capability all on its own.
| dekhn wrote:
| Example: https://www.thingiverse.com/thing:1068443 if not
| impossible, would be very difficult to machine, but is
| straightforward for a printer.
| etrautmann wrote:
| Great point, though I think this isn't a great example - it
| should be straightforward to machine that part with a 5
| axis cnc since all of the suns rays pass straight through
| and an end mill could approach from each of those angles as
| well.
| amelius wrote:
| I wonder if you can make screw threads and how fine using this
| technique.
| monkpit wrote:
| > As a bonus, some compositions resulted in the formation of
| strength-inducing nanoparticles that, with the traditional
| method, require the steel to be cooled and then reheated.
|
| Is this just a fancy way of saying it doesn't require heat
| treatment?
| ezekg wrote:
| If this is interesting to anybody, CGS recently created 3D
| printed suppressors using direct metal laser sintering (DMLS),
| but with Titanium instead of SS [0]. It allows for new geometries
| to suppress the expanding gasses that just weren't possible with
| CNC'd parts welded together. SIG also started producing
| suppressors with DMLS [1].
|
| I don't have one (yet), but the results on sound signature look
| to be pretty impressive [2].
|
| [0]: https://cgsgroup.com/product/hyperion/
|
| [1]: https://www.sigsauer.com/suppressors.html
|
| [2]: https://pewscience.com/sound-signature-reviews-
| free/sss-6-71...
| adolph wrote:
| I wonder if the methods could be used for acoustic suppression
| of other things, like fans.
|
| For example the foam used in the below one wouldn't be useful
| for a kitchen hood fan.
|
| https://www.amazon.com/VIVOSUN-Noise-Reducer-Silencer-Inline...
| pvarangot wrote:
| I'm in California so I can't suppress my firearms because that
| would put the rest of the population in grave danger. That
| being said, the most impressive thing of the sintered
| suppressors rather than the sound signature for me was the
| reduction in blowback. I heard them on pistols and semi-auto
| rifles though, I suppose to truly hear it I should have seen it
| on a bolt action.
| convolvatron wrote:
| thats insane. its animated crystallography.
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