An additive process developed mainly by NASA Langley Research Center materials engineer Karen Taminger uses an electron beam and solid wire feedstock to fabricate structures out of aerospace alloys such as aluminum and titanium. The welding industry has used a similar technique for years, but merely to join parts together. The idea is that the new technique, dubbed electron-beam free-form fabrication or EBF3, will let astronauts on extended missions build replacement parts rather than relying on spare parts that must be carried with them. EBF3 generates no waste and builds parts better than can be done in cast iron and similar to wrought iron. The process, which is said to be fast and economical, can also change microstructures and chemistries as well as build components such as sensors into parts.
The challenge is to build an additive machine small enough to take on space flights, yet versatile enough to handle different types of materials while making a single part. A proof-ofconcept EBF3 machine has been tested in zero gravity and found to work well. The next step is to build smaller machines that can be tested on the International Space Station.