Three-dimensional printing is being used to make metal parts for aircraft and space vehicles, as well as industrial uses. Now NASA is building engine parts with this technique for its next-generation heavy-lift rocket.
The agency says that its Space Launch System (SLS) will deliver new abilities for science and human exploration outside Earth's orbit by carrying the Orion Multi-Purpose Crew vehicle, plus cargo, equipment, and instruments for science experiments. It will also supply backup transportation to the International Space Station, and it will even go to Mars.
NASA is using 3D printing to build engine parts for its next-generation Space Launch System. Shown here is the first test piece produced on the M2 Cusing Machine at the Marshall Space Flight Center. (Source: NASA Marshall Space Flight Center/Andy Hardin)
NASA's Marshall Space Flight Center is using a selective laser melting (SLM) process to produce intricate metal parts for the SLS rocket engines with powdered metals and the M2 Cusing machine, built by Concept Laser of Germany. NASA expects to save millions in manufacturing costs and reduce manufacturing time. SLM, a version of selective laser sintering, is known for its ability to create metal parts with complex geometries and precise mechanical properties.
The SLS will weigh 5.5 million pounds, stand 321 feet tall, and provide 8.4 million pounds of thrust at liftoff. Its propulsion system will include liquid hydrogen and liquid oxygen. Its mission will launch Orion without a crew in 2017; the second will launch Orion with up to four astronauts in 2021. NASA's goal is to use SLM to manufacture parts that will be used on the first mission.
The rocket's development and operations costs will be reduced using tooling and manufacturing technology from programs such as the space shuttle. For example, the J-2X engine, an advanced version of J-2 Saturn engines, will be used as the SLS upper stage engine. Some SLM-produced engine parts will be structurally tested this year and used in J-2X hot-fire tests.
In a NASA video, Andy Hardin, engine integration hardware lead for the Marshall Space Flight Center SLS engines office, discusses the initial testing and building stages:
We do a lot of engineering builds first to make sure we have the process [worked] out. There's always weld problems that you have to deal with, and there's going to be problems with this that we will have to work out, too. But this has the potential to eliminate a lot of those problems, and it will have the potential to reduce the cost by as much as half in some cases on a lot of parts.
Since final parts won't be welded, they are structurally stronger and more reliable, which also makes for a safer vehicle.
Ken Cooper, advanced manufacturing team lead at the Marshall Space Flight Center, says in the video that the technique is especially useful for making very complex shapes that can't be built in other ways, or for simplifying the building of complex shapes. But geometry is not the deciding factor; whether the machine can do it or not is decided by the size of the part.
Thanks, ruffel, glad you liked the article. That's a good question. NASA didn't say what kind, if any, post-sintering processes they're using. They probably haven't figured that out yet, since this is still in the prototype stage.
are these componets used right out of the printer (except the obvious) or do they go through post scintering processes like hot isostatic pressing HIP to improve the density and grain strcture. thanks for a awsome publication
@ChasChas - good question. My guess is that the old design would be printed first so they get an apples-to-apples comparison for their evaluation of the basic mechanical properties.
Robespierre, thanks for your comments on nomenclature. As I posted in the comments section of a different article http://www.designnews.com/author.asp?section_id=1392&doc_id=251754 the term "3D printing" is now used, confusingly, to refer to all types of additive manufacturing. One of the reasons for this is no doubt the fact that the term "3D printing" gets a lot more attention than the term additive manufacturing, probably because it's immediately easier to visualize what's meant, at least by those not familiar with AM. It's also true that much of the actual 3D printing done in the beginning of that version of AM used (and uses) inkjet technology, very similar to the printers that sit on our desks, so it's a valid term for that sector of AM. I'm not sure what you mean by "these types of parts have been manufactured via additive manufacturing for years." NASA using AM to make rocket engine parts is pretty darn revolutionary.
Excellent post! The porous areas intentionally left in the titanium parts are called "net structures". It won't be long before a larger % of all implants are produced in the metal part printers.
Cabe, the term "3D Printing" only confuses people, doesn't explain the various technologies and is a very weak term to encapsulate an entire industry. Supposedly, the term "3D Printing" was supposed to replace the term "Rapid Prototyping" and does a weak job at it because people assume the machinery are printers, such as some cheap thing sitting on a desk. The more powerful term is "Additive Manufacturing" and encapsulates the host of part producing technolgies with strength. Some Additive Manufacturing technologies produce plastic parts i.e. made in Nylon; ABS; Acrylic, etc. and some of these parts are perfectly fine for use as a Rapid Manufactured functional part and are present on space aircraft to this day. Within the Additive Manufacturing industry exist systems that produce parts in metal, layer by layer, and the parts go directly into the human body, or into jet engines. Turbine blades for commercial aircraft are made directly in a select couple of additive manufacturing technologies, with the welds being stronger than the titanium itself. Some parts require the HIP (Hot Isostatic Process) prior to final stamp of approval, but nonetheless, they are functional parts ready for installation. The article here is factual, with the only exception that these types of parts have been manufactured via additive manufacturing for years. It is not new news within the industry but is now coming out as giant leaps in the additive manufacturing metals process has now become better, cheaper and faster.
You probably aren't aware that 3D printing of titanium hip replacements have already captured a large percentage 30%? of the market already. They leave the structure somewhat porous so that the bone can actually grow into it. CT scans are used to create the 3D model used to make the part specifically for your joints. What a great use of this process!
You raise a number of good points, William K. I, too, was impressed by the fact that NASA would consider this process for a functional part. This could be a sign that 3D printing is finding its niche in low-production-volume parts.
As the CAFE standards deadline looms and EPA midterm review begins, automotive engineers are broadening their materials use to help vehicles shed weight and using more fuel-efficiency technologies.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
0 
