3D-printed rocket parts stand up to the heat in NASA hot-fire tests
3D printing technology has already made the move from engineering workshop to the home, and now it's set to make its mark in space. NASA has hot-fire tested 3D-printed rocket engine components, which have managed to withstand incredibly high temperatures and pressures to the same standard as traditionally manufactured parts. Being cheaper and faster to produce, 3D-printed parts have the potential to revolutionize the manufacturing of rocket engine components and save the space agency considerable time and money.
Obviously, reliability is a key factor when it comes to rocket engine components, so engineers at NASA’s Marshall Space Flight Center have been putting two 3D-printed subscale injectors to the test and comparing their performance to components manufactured the traditional way. In 11 different hot-fire tests, the two 3D-printed injectors were subjected to a total of 46 seconds of firing time at temperatures nearing 6,000° F (3,316° C).
"We saw no difference in performance of the 3D printed injectors compared to the traditionally manufactured injectors," says Sandra Elam Greene, the propulsion engineer who oversaw the tests. In fact, the 3D-printed parts stood up so well to the tests that engineers at the Marshall Space Flight Center will continue to put them in the line of fire in further testing.
The Marshall Center engineers built the subscale injectors as a one-piece component in just three weeks and at a cost less than US$5,000 by sintering Inconel steel powder using a state-of-the-art 3D printer. In comparison, traditional subscale rocket injectors are made up of four parts and take six months to fabricate, weld, and machine at a cost of more than US$10,000 each.
"It took about 40 hours from start to finish to make each injector using a 3D printing process called selective laser melting, and another couple of weeks to polish and inspect the parts," explained Ken Cooper, a Marshall materials engineer whose team made the part.
NASA has been testing 3D-printed parts for some time now. The J-2X engine exhaust port was the first 3D-printed component that was hot-fire tested by NASA, back in 2012, but its repertoire is growing quickly.
"Rocket engines are complex, with hundreds of individual components that many suppliers typically build and assemble, so testing an engine component built with a new process helps verify that it might be an affordable way to make future rockets," says Chris Singer, director of the Marshall Center's Engineering Directorate. "The additive manufacturing process has the potential to reduce the time and cost associated with making complex parts by an order of magnitude."
Additive manufacturing and 3D printing appear to not only be the wave of the future when it comes to making things at home, they are improving the design process for the world's top engineering minds at NASA.
The video below is one of the hot-fire tests.
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The question remains as to what kind of wear an tear the printing nozzles will undergo with the abrasiveness of the metal powder.
Nickel and chromium normal ingredients in stainless steal therefor Inconel steel would presumably be a high alloy stainless steel.
Sintering is a process of welding together a metallic powder to form solid pieces. If you lay down a thin layer of metallic powder and use a laser or particle beam to weld in only the material needed for the part you are building it is 3D printing. You could also lay down differing powders if you needed to heat the building material to a higher level of fluidity without having extra material stick to it. In which case you will need a printer head.
You could at least in theory 3D print with a MIG or TIG welder. But since the only ark welding I have done is with a stick welder I do not know what level of precision you could achieve.
There was a correction in the article after my comment. And from what you describe this is exactly how the process was done. I am a retired person and have not kept up with the current technologies in manufacturing processes. I just stated what I knew from my past experiences.
Thanks for the info. I learn a lot from this site as well as from comments of knowledgeable people like you. It at least keeps the grey matter going completely black !
No, stainless steel is mostly iron with much lesser amounts of chromium and nickel, the exact proportion of the ingredients depending on the final purpose of the alloy and how much you're willing to pay.
For example, common stainless alloys might be 18/8 or 18/10, the numbers representing the percentages of chromium and nickel respectively. Throw in a few percent of molybdenum if you want salt water stainless, and no doubt there are dozens of other mixes for specific purposes.
According to Wikipedia, Inconel is mostly nickel and chromium, and iron is a strictly optional extra among many choices, depending on the properties and mix that you want.