Today, we have two links for you that will expand your knowledge of what the DOD and Aerospace world is doing with additive manufacturing.
Additive Manufacturing for Armaments
The first is slightly dated, because it comes from the NDIA’s 2013 Armament conference. (Yes, 2013 was a long time ago in this rapidly developing field). It is the presentation slides of Stratasys’s John Dobstetter. Stratasys (SSYS) is one of the two large publicly traded firms in the field (the other is 3D Systems, whose ticker symbol fits: DDD).
Personally, we wouldn’t cross the street to whiz on Stratasys if they were on fire, because the company is firmly antigun and pro-gun-control, but Dobstetter’s presentation is an excellent one that starts out assuming that (1) his audience knows nothing about additive, but (2) it’s a bunch of smart people who know manufacturing and catch on quickly.
There’s fascinating stuff about when to use additive (see the Sweet Spot slide above) and how it can be applied to every phase or stage of manufacture (see the Lifecycle Applications slide to the right). Switched-on manufacturers, like Czech airplane manufacture Evektor, are using additive parts both as tooling and as end use parts.
There are some extremely clever uses of additive, either alone or hybridized with other tools, for composite layup tooling, producing some very interesting carbon, glass and aramid (Kevlar) parts. Likewise, end uses can be hybridized, with additive-manufactured complex ends added to shafts or beams made by winding filament or tow around a simple metal mandrel.
A .pdf of Dobstetter’s presentation is found here in the archives of the 2013 Armament conference.
Additive Manufacturing for Aerospace
MIT Technology Review has an interesting article (aren’t they all? Well, in MIT Tech Review, maybe) called Additive Manufacturing Is Reshaping Aviation. In this case, they’re not talking about little piston-plane builders like Evektor or Cirrus, but the big gorillas of jet-engine production, Pratt & Whitney and GE.
Pratt & Whitney already uses two additive manufacturing techniques to make some engine components. Instead of casting metal in a mold, the methods involve forming solid objects by partially melting a metal powder with either a laser or an electron beam.
Additive manufacturing processes can reduce waste, speed up production, and enable designs that might not be feasible with conventional production processes.
Ding ding ding… we have frequently mentioned this benefit, the ability to design things free of the shackles of traditional subtractive manufacturing.
The novel shapes and unusual material properties the technology makes possible—such as propeller blades optimized for strength at one end and flexibility at the other—could change the way airplanes are designed.
Of course, propeller blades are already optimized that way, by having taper in three dimensions. And a company named Carter Aviation Technologies has developed revolutionary propellers that use a flexible composite skin around two spars that flex like the bones in your forearm to change the delta of pitch in the propeller, whereas conventional propellers can only change the pitch itself, not its rate of change. (Hey, you could use the additive tooling that Dobstetter showed in the first cite to make all the iterations of a Carter-patent propeller that you could possibly use).
Meanwhile, engineers hold out hope for today’s amazing technology to be supplanted by better machinery — finer resolution, faster printing, better-understood statics & mechanics. Even as great as the state of the art is, the engineers must push it:
…additive manufacturing techniques need to improve to allow for higher precision. Once researchers understand the fine, molecular-scale physics of how lasers and electron beams interact with powders, [P&W engineer Frank Prelli] says, “that will lead to the ability to put in finer and finer features, and faster and faster deposition rates.”
Whatever happens with the jet engine makers and the airframers that are their major customers, we can expect more and better from additive manufacturing. While the whole thrust of the article is aerospace, it has clear applications to defense and firearms manufacturing.
And A Bonus from MIT Tech Review: Nanosteel
What happens to steel when you apply nanotechnology to it?
MIT Tech Review’s Kevin Bullis (same guy that wrote the additive article linked above) is saying things that scarcely seem possible:
An inexpensive new process can increase the strength of metals such as steel by as much as 10 times…
Can you think of a firearms application for that? Or about 100 of them? We sure can. (Saving 90% of the weight of a Browning MG in .338 LM?)
But wait! It turns out it doesn’t just strengthen the steel… it also makes it much more corrosion-resistant. It works by electroplating nanometer-thing material onto a part in nano-engineered layers. It has the effect of changing the apparent properties of the now-hybridized part.
And it’s not significantly more expensive than current plating and coating processes.