Engineers at NASA’s Langley Research Center in Hampton, VA, have developed an environmentally friendly manufacturing process called Electron Beam Freeform Fabrication (EBF3). “You start with a drawing of the part you want to build, you push a button, and out comes the part,” said Karen Taminger, technology lead for the project. EBF3 works in a vacuum chamber, where an electron beam is focused on a constantly feeding source of metal, which is melted and then applied as called for by a drawing — one layer at a time — on top of a rotating surface until the part is complete.
To make EBF3 work, there are two key requirements: A detailed 3D drawing of the object to be created must be available, and the material the object is to be made from must be compatible for use with an electron beam. First, the drawing is needed to break up the object into layers, with each cross-section used to guide the electron beam and source of metal in reproducing the object, building it up layer by layer. Second, the material must be compatible with the electron beam so that it can be heated by the stream of energy and briefly turned into liquid form, making aluminum an ideal material.
The EBF3 can handle two different sources of metal at the same time, either by mixing them together into a unique alloy or embedding one material inside another. The potential use for the latter could include embedding a strand of fiber optic glass inside an aluminum part, enabling the placement of sensors in areas that were impossible before. Future lunar base crews could use EBF3 to manufacture spare parts as needed, rather than rely on a supply of parts launched from Earth. But the immediate and greatest potential for the process is in the aviation industry, where major structural segments of an airliner, or casings for a jet engine, could be manufactured for about $1,000 per pound less than conventional means.
Environmental savings also are made possible by deploying EBF3. Normally, an aircraft builder might start with a 6,000- pound block of titanium and machine it down to a 300-pound part, leaving 5,700 pounds of material that needs to be recycled and using several thousand gallons of cutting fluid used in the process. With EBF3, the same part can be built using only 350 pounds of titanium and machine away just 50 pounds to get the part into its final configuration.
For more information, visit www.nasa.gov/topics/aeronautics/features/electron_beam.html.