Educate me on sintered metal 3D printing

[bkreigsr]

I've read where it's being used in the medical world, but how about automotive applications?
What says the brain trust?
Bill K

[mjohnson]

I'm a metallurgist.

The 3D stuff is going to have some interesting properties dramatically different from those that we've learned to live with for the last 150 years or so.

For one, the powder feedstock drags lots of exciting things into the mix. One of the benefits, and the downsides, of powders is that they have large surface:volume ratios. Lots of area there for interesting things to happen in your base materials.

We have generations of knowledge of blast furnaces and steel mills. We understand all of the inclusions, the defects and the anisotropy inherent to those processes. AM will be just as far from ideal but likely in many different ways.

As a materials guy it's exciting...

[bkreigsr]

Originally Posted by mjohnson

I'm a metallurgist.....As a materials guy it's exciting...

Thanks for that MJ.
So the key is to be able to filter out all contaminates that would be harmful?

A close friend of mine recently took the big jump and joined as one of the major players in a startup 3D print company.
All the research I've done points to this as being the next Silicon Valley.
But I've been wrong before.

Bill K

[aschen]

Its best for relatively small and intricate parts still, especially suited to parts that cant be made otherwise (odd internal passages or non homogeneous solid parts). The next decade or so will be exciting for mfg engineering. I do think the medial sort of blew up the relative significance of the tech a few years ago. Sure its a big thing but they acted like it was a brand new disruption. Additive mfg has been slow and evolutionary in my experience.

We had an SLS machine in our ME lab (Purdue) when I was in undergrad circa 1996. The metal machines and processes still seem quite involved Im not sure they will get down to the home gamer level like the plastics machines.

[Rikao4]

just watched something about this ..
Jay Leno's garage series..
his guys used fab & swag unobtanium parts..
now they just need a good picture / diagram or part..

Rika

[Marcup]

Being able to make a small part just by creating a solid model gives you the illusion that the part will be great.

Actually, it is difficult to insure the material properties are consistent and match what you are use to using.
You need a great deal of experience with the particular material, machine and materials testing to know what the properties are.

Typically the price for parts is much higher than for "normal" processes - assuming you are making more than a few.
The small lot can be cheaper, but there is the problem of knowing the material properties.

If you are going to make parts with cavities and the parts are going to be highly loaded, the rough interior surfaces can possibly cause cracking under repetative load.

Most of the powder not used in a production is treated as hazardous waste (Ti in the example I checked) and not reused due to product consistency issues.
Most metals cannot be used in this process. Ti and stainless steel are "common". Aluminum will not produce useful parts (low material properties and were not offered.

On the other hand, there have been some well developed "supermetal" alloys which were successful (jet engine parts) and cheaper in small production runs.

The technology is changing all the time. Lots of research

The Air Force thought they could make spare parts for old aircraft (out of production) by just copying the shape of the aluminum parts and make them in titanium.
They quickly realized that the increased stiffness of Ti would potentially cause increased loading in adjacent parts and cause them to fail - unless the adjacent parts were also redesigned. Which then progressed to the next parts, etc, etc.

This is not a one size fits all technology.

But very interesting. And very expensive machines.

[Marcup]

Another key point about the technology.

The parts have to fit in the cubic area built into the machine. So each machine has a distinct limit.

During parts manufacture, the entire volume that the part requires is filled with the powder. Any powder not consolidated is then scrap. This is expensive powder.

So good parts are not widely spaced frames like shown above. They are typically smaller and able to be packed tightly in the working volume of the machine.
The better packed and the better the fraction of the power used results in parts that are cheaper.

As an example, plastic printed parts were quoted to me on the basis of # of inches of powder required.
If you had a 1" high part, it cost $200 for either one part or 10 if they laid in that 1 inch space.

[intakexhaust]

As an outsider and one who enjoys looking at advanced tech, I become both skeptic yet want to see success. Totally get it for modeling though.

For example, looking at the OP and images, control arms, uprights, susp. pieces and being very skeptic for two reasons.

Material strength for application and the other is in time of fabrication vs. traditional methods.



Other:
Ford has an angle and new marketing concept coming. For a unique and personal touch, customers will be able to design their own bits and pieces and have Ford pop them.

[David]

I've seen some interesting gas turbine development work with 3D printing where the turbine nozzle internal cooling passages are pretty wild.

Something more useful for most of us is the 3D sand printing for castings. It makes it much easier to make one off castings. Think of 930 swing arms, out of production engine heads, etc.

[island911]

+1 to Marcup.

I'll add that the tech induces internal stresses, due to the generally high thermal gradients during the fusing process.

No doubt additive methods will continue to improve, as those machines get more and more sophisticated.

[BlueSkyJaunte]

Originally Posted by island911

I'll add that the tech induces internal stresses, due to the generally high thermal gradients during the fusing process.

That sounds like something a good heat treating regimen could easily resolve...but I come from the caveman school of metallurgy where we beat on hot steel with a hammer.

The most intriguing application of DMLS that I've seen is in firearm sound suppressor fabrication. The internal baffle structures can be made MUCH more efficient than the typical "k-baffle" and "monocore" designs that most manufacturers use. If these things weren't so damned expensive (not to mention the hoops you have to jump through to own one) I'd buy one just so I could saw it in half and see what the guts look like.

http://deltapdesign.com/