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Desktop Metal gets $115M in funding to deliver metal 3D printing

techcrunch.com

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Re: Desktop Metal gets $115M in funding to deliver metal 3D printing

#4

Post by zwieback »

elihu wrote: post #3

Sounds interesting; any details on how it works, what materials it can be used with, what are the consumables, strength, accuracy/resolution, maximum size, etc..?

Here's a little more detail: https://www.theverge.com/circuitbreaker/2017/4/26/15440744/d...

The important thing to remember is that the 3D printing doesn't generate the final part, the plastic binder in the filament has to be burned out and then the part has to "densify", e.g. the actual sintering where the metal particles fuse together creates the final material properties of the part.

The final part will be a lot smaller than the thing coming out of the 3D printer, controlling uniform shrinkage is probably a lot of the secret sauce.

Re: Desktop Metal gets $115M in funding to deliver metal 3D printing

#5

Post by dogma1138 »

elihu wrote: post #3

Sounds interesting; any details on how it works, what materials it can be used with, what are the consumables, strength, accuracy/resolution, maximum size, etc..?

Looks like fused jet deposited powdered metal printing.

Strong but not nearly as strong as casting (especially without secondary processing), as for materials powdered metal printing is usually either ferrite alloys or nobel metals the former is much more common.

Resolution is in single digit microns or finer.

This is based on similar products not this specific one, it might be faster which is important but there is only that much you can improve on the process.

The speed also to me looks like a result of very limited market in terms of competitiveness. Existing products are few and they rather sell you more machines than drastically improve the printing speed by making it much smaller and focusing on smaller parts.

I don't know if they use induction or optical fusing based on the size I would go for optical so they might have found a good laser or a absorption facilitating epoxy/flux to go with the powder.

Edit: based on a comment here it looks like they don't do fusing as part of the print.

In this case its metal powder with a chemical binder (glue) which usually contains flux and vaporizes at a fairly low temperature.

After the printing the parts go into an oven (usually encased in sand for temperature control)

The oven brings the part to a high enough temperature for the crystal formation but not close to the melting point.

In this process larger crystals can form but not nearly as large as with cast forging.

Re: Desktop Metal gets $115M in funding to deliver metal 3D printing

#6

Post by dogma1138 »

zwieback wrote: post #4
elihu wrote: post #3

Sounds interesting; any details on how it works, what materials it can be used with, what are the consumables, strength, accuracy/resolution, maximum size, etc..?

Here's a little more detail: https://www.theverge.com/circuitbreaker/2017/4/26/15440744/d... The important thing to remember is that the 3D printing doesn't generate the final part, the plastic binder in the filament has to be burned out and then the part has to "densify", e.g. the actual sintering where the metal particles fuse together creates the final material properties of the part. The final part will be a lot…

Does it actually has to go trough forging and tempering? They don't have a fusing element in the head?

Re: Desktop Metal gets $115M in funding to deliver metal 3D printing

#8

Post by ortusdux »

dogma1138 wrote: post #5
elihu wrote: post #3

Sounds interesting; any details on how it works, what materials it can be used with, what are the consumables, strength, accuracy/resolution, maximum size, etc..?

Looks like fused jet deposited powdered metal printing. Strong but not nearly as strong as casting (especially without secondary processing), as for materials powdered metal printing is usually either ferrite alloys or nobel metals the former is much more common. Resolution is in single digit microns or finer. This is based on similar products not this specific one, it might be faster which is important but there is…

I don't see the advantages to this over lost-PLA casting. Am I missing something?
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