Laser sintered metals how good are they?

Hi Guys,

I’ve been reading about laser sintering, which is a CAM process, and
am wondering if the hype is just hype.

In that :-

“Laser Sintering provides a wide range of part properties, from
controlled porosity for venting or filtering to fully dense
structures which can have a higher strength than castings and
forgings.”

So how true is this?

Regards Charles A.

Charles,

it is a very neat process, however. the process isn’t exactly a pure
one.

Generally, what happens is a powder alloy (I think a bronze) is
sintered and then baked. this is a porous material. That then is then
impregnated and fused with the metal of your final choice.

You can get a sample of the materials for a price.

http://www.ganoksin.com/gnkurl/ep7zvj

Cheers,
Chris

"Laser Sintering provides a wide range of part properties, from
controlled porosity for venting or filtering to fully dense
structures which can have a higher strength than castings and
forgings." So how true is this? 

It depends on the alloys being sintered but yes these are some of
the properties that can be achieved.

James Binnion
James Binnion Metal Arts

I am asking questions along these lines as well Charles. Some very
interesting claims are being made for lasers to cut and shape and
engrave metal and stone.

If you think of this in terms of robotic end-effectors, there is a
three-way competition now between grinding end-effectors, water-jet
and laser.

I would suggest that those interested invite the laser suppliers to
contribute their comments and we can take it from there. If there is
enough interest I will post further from my findings to date.

As for “hype” as you wisely alert us to below, there is no better
test of proof v hype than the product of the machine.

Generally, what happens is a powder alloy (I think a bronze) is
sintered and then baked. this is a porous material. That then is
then impregnated and fused with the metal of your final choice. 

Nah not that Shapeways stuff, that’s very crude in comparison to the
stuff that’s coming out now.

The reason I posted this discussion topic, was because of this :-

http://www.ganoksin.com/gnkurl/ep7zv9

Kindly provided by another list member. I’ve sent of an information
request to see if I can get some to share.

This level of tech is a vast improvement on the shapeways tech.

I checked out a few other industrial sites using sintered metals.
They are stating the same thing, that the level of porosity can be
controlled, and that the resultant items are stronger than castings
and forgings.

Just wondering if anyone on the list has tried the new tech yet?

Regards Charles A.

"Laser Sintering provides a wide range of part properties, from
controlled porosity for venting or filtering to fully dense
structures which can have a higher strength than castings and
forgings." So how true is this? It depends on the alloys being
sintered but yes these are some of the properties that can be
achieved. 

That is very interesting, it may replace the CAD → Wax casting
pipeline with CAD → Laser sintering pipeline for jewellery if it
can provide a superior product.

I’ll have to see if it’s available in Australia for testing
purposes.

Regards Charles A.

That is very interesting, it may replace the CAD -> Wax casting
pipeline with CAD -> Laser sintering pipeline for jewellery if it
can provide a superior product. 

Oh it is not really a superior product. There are a couple of
issues, first the surface quality is much worse than what you can
get from a good RP model that is molded, wax injected and then cast.
Hell even straight to invest and cast RP models have better surface
finish. The laser is melting little bits of powder, this makes for a
chaotic surface as the exact size of the melt puddle is based on the
powder stacking in the immediate area of the laser focus. It is not
a horrible surface but one would need to do a lot of finishing to a
piece to get a typical jewelry quality surface. The pictures they
are showing of the nice shiny parts have been through a major amount
of cleanup and polishing. I have held the raw parts in my hands they
are rough. The second really big problem is cost. The machines are
in the $300,000 US range and the build cavity holds about $400,000
US in 18 K powder and you need more than that on hand to actually
make parts. So one has over $700,000 US in machine and material that
has to be amortized, the machine is not terribly fast so the cost
per hour for the use of that machine is going to be astronomical.
Even the machines that are producing stainless parts are way too
expensive in cost per hour for consumer items. I really don’t
believe the proper market research has been done if they think they
will sell many of these machines into the jewelry business.

I dont see them being used for anything other then the wow factor.

James Binnion
James Binnion Metal Arts

Very cool!

I checked out a few other industrial sites using sintered metals.
They are stating the same thing, that the level of porosity can be
controlled, and that the resultant items are stronger than
castings and forgings. 

wonder if it is essentially the same (just newer refinement) or are
the sintering the final alloy directly.

Christopher Lund
Neurascenic - Industrial design

What application did you have in mind for sintering (low temperature
fusing), Charles? I got imaginative and studied the pictures of
projects at http://www.ganoksin.com/gnkurl/ep7zw6 (I have no vested
interest in the company - this is arms length). Here is an
application I thought of. First the laser could be used at a higher
temperature to engrave the metal or stone. The laser etched grooves
and pits of the art work could then be filled with powders for
sintering (“powder metallurgy” as it is sometimes called) and a lower
temperature stage of laser could then be applied to sinter the
powder. Is that what you had in mind? Sintering could also be used
to bond pieces in a large stone or metal sculpting.

If so, I think this might be like kiln enamelling without the kiln.
You could be sintering in all sorts of enamels for artistic purposes
as well as simple structural joining. I have no experience with this
so I was hoping others on Orchid do and might share their experiences
with laser technologies. One plus for sintering is that it might
preserve the integrity of the granite, marble etc. whereas the kiln
would destroy it which means a lot of jewelry applications.

The bigger picture here is that I have to wonder if laser will win
out over grinding and water-jet CNC (Computer Numerical Control)
applications. All seem amazing capable of surpassing human visual
discrimination for precision work. All can be used for cutting and
shaping material. But the laser has a big plus - an amazing
temperature range. Affordable desk top lasers are now on the market.
CAM (Computer Assisted Machine) with laser peripheral/end effector
might become standard, everyday jewelry equipment in the near future.
What do you think?