3D Printing in Metal: the Laser and Metal Powder Printers We Saw at IMTS

Last week I went to the International Manufacturing Technology Show (IMTS) and it was incredible. This is a toy store for machinists and showcases the best of industrial automation. But one of the coolest trends I found at the show are all the techniques used to 3D print in metal. The best part is that many of the huge machines on display are actually running!

It’s probably better to refer to this as additive manufacturing, because the actual methods can be significantly different from your 3D printer. Below you’ll find examples of three different approaches to this process. I had a great interview with a company doing actual 3D printing in metal using a nozzle-based delivery often called cladding. There’s a demo video of powder layer printing using lasers. And a technique that uses binders as an intermediary step toward the final metal part. Let’s take a look!

BeAM is Using Directed Energy Deposition

It was great to run into Tim Bell who was showing off this huge jet engine cone at the BeAM Machines booth. The cone itself was spun out of stainless steel as the fastest and most economical way of producing it. The isogrid was printed on the outer surface of this cone, a structure that is usually machined out of a larger part in a subtractive process.

BeAM is using a nozzle-based approach that carries metal powder in a stream of argon gas. As it exits at the tip of the nozzle, a high-powered laser fuses the material. Tim mentioned that any material that can be laser welded can likely be used in this process. That includes titanium alloys , steel, nickel alloys, and cobalt alloys. They are also working on aluminum.

Adding to an existing part is really cool, but of course you can also print entire objects like the ones shown here. Tim did mention that printing an entire jet engine cone in INCONEL 625 (a nickel-chromium alloy) would have been prohibitively expensive.

BeAM didn’t have a machine on site that was up and running, but there was one company demoing laser cladding so let’s take a look at that.

Laser Cladding: Metal Deposition for Building Up Parts

It’s pretty awesome to see these machines in action on the show floor. Here is a laser cladding machine by O.R. Lasertechnology that was demonstrated building up a helix on some bar stock. I shot some video which shows the powder coming out of the nozzle before the laser fires up. Once that happens, the spinning of the jig and linear movement of the nozzle build up the spiral.

The machine wasn’t too large, about the size of a refrigerator. You can see what a finished rod looks like. I believe this one has been polished to get this finished look.

The Toshiba booth didn’t have a laser cladding machine on display, but they brought along some sample parts. Here you can see how these have been built up and then machined back down to tolerances.

Laser Sintering: Renishaw renAM 500Q

This Renishaw printer has four 500 W lasers. Yes, two kilowatts of laser in this relatively small machine! The video I shot shows off the laser ballet as it fuses a layer of metal powder. At the end there’s a gantry that sweeps a fresh layer into place for the next iteration.

The printed manifold on display is just fantastic. I wouldn’t have been able to pick it out as laser printed. It’s titanium and took about 40 hours to print the two parts that make it up. Parts that come out of this machine need to be bead blasted to clean them up — perhaps that’s why it doesn’t look 3D printed — and titanium parts, like this one, need to be heat cured.

Renishaw was also showing off a delta bot that they built as a gauging system for checking the specifications of parts. Seeing the resolution demo is eye-popping and operating on those scales illustrates the need for confirming the precision of the parts that come out.

3D Systems Laser Sintered Metal Printing

3D Systems had a big direct metal printing machine which is used in aerospace and medical technology. (Get your custom hip here!) It wasn’t running but I got a great look at the print bed and an explanation of how it works.

The center part of the bed sinks into the machine as each layer is printed, and powder is swept in from either side. The laser is mounted above, pointing downward. Parts are printed on a raft that adheres to the bed. This serves as a jig for post-processing steps, after which the part is removed using EDM.

HP Enters the Metal Printing Market

Hackaday’s Al Williams just wrote about the HP Metal Jet on Friday, I got to see it in person! This is a brand new line of metal printers and I’m including it here even though there are no lasers involved. This sprays a binding agent onto the powder and applies a bit of heat to cure the binder as the layers are built up. The fully printed part needs to be run through an oven curing process before it’s complete. Apparently it was running while I was there, although the machine is designed so that you can’t see inside so there’s not much to show you on this one.

Metal Printing is Already In Use

These metal printers are currently relegated to aerospace, medical, and high-end prototyping; think automotive industry. The important thing to keep in mind is that with the exception of the HP which was just unveiled, these machines are all in use already. It was a ton of fun to see all of the metal printing on offer at IMTS, and to realize that these technologies are only going to get better!

Keep your eye on Hackaday as we have a few more really interesting machines from the show that we’ll be sharing in future articles.

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