Boeing Dreamliner Gets $3M Cheaper Thanks to Rapid Plasma Deposition | Hacker News Reader

Boeing Dreamliner Gets $3M Cheaper Thanks to Rapid Plasma Deposition

pcmag.com

62 points6stringmerc32 comments

That's a very clever trick. Titanium is a really difficult material to machine and by doing it this way they only have to do the final couple of passes rather than to start from a blank. And for a part that would turn most of the blank to chips the reduced cost in tooling (and material, contaminated Titanium scrap is worth a lot less than Titanium stock) must be enormous.

The press release linked by the article has an image of the production facility ...

Norsk Titanium to Deliver the World’s First FAA-Approved, 3D-Printed, Structural Titanium Components to Boeing

http://www.norsktitanium.com/norsk-titanium-to-deliver-the-w...

When can I afford one for my home office?

Hmmm... do you have any first-order relatives who's names begin with "Count" or "Duke", or something along those lines?

Kidding aside though, what an amazing machine; wouldn't it be great if they were in the price-range where a group of hobbyists could pitch in to rent one together?

It's great to see 3D printing winning on cost, because this is normally a great reason to adopt a new technology. Norsk's RPD process looks to be built for high speed and low cost (plasma torch, argon gas, titanium wire).

I think processes like RPD, Sciaky's EBAM, and Arcam's EBM are generally going to win on price compared to traditional laser sintering like EOS DMLS in the long term, especially for big parts. They replace expensive metal powder with cheaper powder (EBM) or wire (EBAM, RPD), and expensive fiber lasers with more powerful and cheaper electron beams or plasma torches.

It's hard to get fast large-scale metal deposition with a laser: the EOS M400-4 seems one of the highest power laser based solution with 4x 400W fiber lasers (Concept Laser has a 2x 1 kW model). Sounds fancy until you realize that's about as much power as a nice microwave. For comparison, Hypertherm sells 80 kW plasma torches, and Skiaky sells 42 kW electron beam welding systems.

Cooling the parts being printed is a big problem since printing a big glowing puddle isn't very useful, but increasing build volume / part size helps drop the power density.

Is there some kind of equivalent power rating for the purpose of comparing plasma cutters and lasers?

Wherever it comes from, the power is used to melt metal, so the power puts an upper limit on how fast material can be printed.

I don't know what percentage of the plasma energy in RPD is transferred to the metal, but fiber or CO2 lasers are significantly less efficient than electron beams (~40% vs ~70% absorption based on a very brief search).

It's worth noting that in the picture from the article of the printed piece, what they're actually doing is building up a near-net part and then sending it off to be machined down to it's final spec. It appears similar to the process of using a TIG welder to rebuild a severely damaged engine block or other metal part and then machining it back to spec.

Yes that's correct. You could call it Laser Cladding, Directed Energy Deposition, or Laser Metal Deposition

If I'm not mistaken, it's cheaper to build titanium in a hybrid process like this, compared to milling a large block of titanium. 3D printing has found it's cost efficiency with titanium and it's not even because of complex geometry. The industrial potential is massive.

Yep. Machining large volumes of Ti is a PITA. You'll burn through (expensive) tooling super fast.

How strong is the new material compared to the old approach?

Since they're using it for wiring harnesses, sounds like these parts are extremely numerous and can add a lot of weight if a cheaper material like aluminium was used. No doubt they have some pretty strict strength requirements, but they're not holding the plane together per-se.

A plastic part would probably work but for issues of fire safety, wear from friction, and other factors like that.

I remember reading that getting good 3D printed/sintered titanium was a big thing for spacex rapid assembly - I wonder if they use the same techniques...

e.g. http://hackaday.com/2016/05/19/its-time-for-direct-metal-3d-...

SpaceX 3d prints the entire SuperDraco engine, which is used for orbital aborts of their crewed Dragon, and eventually for landings of crewed Dragon and cargo Dragon 2.

Oh neat! I live not too far from Plattsburgh, where Norsk Titanium has its US facilities. They're doing very good things for an otherwise pretty depressed economy up here.

Titanium is very corrosion resistant, AFAIK it can be directly bonded to carbon fiber.

On the boats I used to work on, it was common to bond Mg or Ti ribs to a carbon shell for increased durability. I bet they're using a similar process with the wing roots/spars in the airliners.

Thoughts on reinforcing the bow of a sailboat with titanium to prevent vessel loss due to collisions with floating cargo containers while blue water cruising?

I thought containers don't float anymore these days because of built in flood valves?

You're assuming the contents isn't buoyant. What happens if its a container full of polystyrene beads or something? :)

Depends on the bow shape really. If its a newer one with a relatively squared up bow, you're kinda screwed since it's much harder ride over hard objects. If the bow is rather shallow you can just add a few layers of carbon and you'll have no problem riding over any objects with minimal damage. That said, you'll still probably screw up your keel.

What is the probability of that happening? I know it occurred in a really poor movie[1][2], but I cannot believe this is common enough to warrant the effort. Also, wouldn't early detection be a better / cheaper alternative?

1) http://www.imdb.com/title/tt2017038/

2) https://youtu.be/YwmVpHJeqgY?t=7m27s

It's basically not going to happen but hitting flotsam in general is a concern in some situations. I used to boat on the Cuyahoga for instance and floating microwaves will fuck you up.

Also, detection of floating objects is actually really hard. Waves create a ton of noise and if you google "floating shipping container" you'll see they typically float with a corner sticking up, making them a somewhat inefficient radar reflector (there's a reason the F117 is shaped the way it is).

I was more thinking sonar. There seems to be quite a few companies selling obstacle avoidance sonar that have some pretty cool displays.

Sonar doesn't typically work very well looking forward near the surface. For larger craft the transducer could be mounted low enough to look up slightly but even then you have surface interference issues. A container might be a big and deep enough target to pick up on something mounted to the bottom of a sailboat keel perhaps but definitely not the bow.

From a signals perspective, things that live right on the edge of the water/air boundary are kind of a pain to detect. Unless the water is perfectly still, there's so much noise that you need a lot of spatial resolution to actually see anything useful

That's unexpected: one would assume use carbon for the ribs too.

What titanium is better for is high point loads and abrasion.

They use carbon now. This was an old design (mid 2000s)

Are you sure? Titanium sublimation pumps exist because Ti is so reactive. Perhaps the reactivity is self limiting with depth

Like aluminium, it's extremely reactive with oxygen and nitrogen. It rusts almost instantly. The rust also creates a protective barrier that prevents further corrosion.

Titanium oxide isn't very reactive.

Yes, this is one reason titanium is used in implants. It corrodes quickly on the surface, but the thin corroded layer protects the metal underneath.

Might this technique also be applicable for bicycle frames?

Boeing will be overjoyed at that news being publicised. All its customers will be asking for a $3m discount on their orders now.

If it's anything like the automotive industry, their customers already have a contract that specifies the price going down for the next decade. Customers know that you'll improve your process, get more efficient, develop a supply chain, learn to spot problems before they surface, automate repetitive actions, and train your technicians as the years go by.

The contracts specify prices and quantities years in advance - with later years at lower cost than the first years. I suspect that someone guessed years ago that while these titanium parts might need to be made with expensive machining initially, they could eventually be built using EDM, casting, or 3D-printing, and factored that into their budget at Boeing or their contract as a customer.

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