Beam-Deflection Control System for Deposition-Based Manufacturing

E-beam fabrication and manufacturing:
Rapid prototyping
Custom part and small-batch manufacturing


Ion/E-beam processing:
Welding
Sputtering
Physical vapor deposition

NASA created this technology (as well as other related technologies) as part of its effort to develop an EBF3 system for manufacturing large, complex parts in remote locations. NASA’s EBF3 system uses an electron beam to melt a metal wire and then accurately deposit the molten metal onto a substrate, building a part layer by layer according to computer-aided design (CAD) data.

Similar manufacturing systems use a defocused beam, with all of its energy directed into the pool of molten metal. However, researchers at NASA’s Langley Research Center realized that controlling the beam would allow for more efficient use of its energy and better parts. It also could enable previously impossible manufacturing opportunities.

Tests show that this beam-deflection control system ensures that EBF3-manufactured parts meet metallurgical specifications consistently, with better surface properties and fewer residual stresses while using less energy.

How It Works

This thermal image illustrates how beam rastering was successfully used to direct the wire into the molten pool as well as to induce a square trailing edge on the molten pool.

NASA’s innovative technology uses advanced beam rastering (i.e., pulsing the beam off and on while moving it to a new focal coordinate) to control the beam’s direction and power. By precisely moving and focusing the beam in various locations during fabrication, the technology can selectively heat the metal being deposited, controlling multiple characteristics simultaneously.

In NASA’s EBF3 technology, which uses a metal wire as the feedstock, the rastering ensures that the wire does not move out of the molten puddle as it melts, resulting in consistent material delivery during deposition of each layer. Precise deposition is important to ensure high-quality parts because an error of as little as a few hundredths of an inch can become significant when repeated over multiple layers. In other deposition-based manufacturing systems, a similar approach can be used to control the temperature in the molten pool. (This aspect of the technology closely relates to the closed-loop process control technology, which also is available for license.)

Rastering also can be applied to the beam so that it provides more general heating. For example, directing the beam to apply a small amount of heat in front of (or behind) the melt pool provides pre-heating (or heat treatment) that yields a better deposition layer and, consequently, a better final part. Directing the beam also can reduce distortion and residual stress, strengthen the material by applying compressive stress, or aid in surface shaping.

Why It Is Better

Programming a rastering pattern on the beam ensures that the metal feedstock melts consistently and in a self-correcting manner without the need for sensors, although sensors and an adjustable raster pattern can be incorporated, allowing the system to be integrated into a closed-loop system. Regardless of the configuration, this approach successfully maintains process consistency and yields high-quality parts, as demonstrated in numerous tests.

Patents

NASA has filed for patent protection for this technology.

This technology is part of NASA’s Innovative Partnerships Program (IPP), which seeks to transfer technology into and out of NASA to benefit the space program and U.S. industry.

NASA invites companies to consider licensing the Use of Beam Deflection to Control Electron Beam Wire Deposition Processes (LAR-17245-1) technology described here for commercial applications.

Companies also may license any or all of the following additional technologies in conjunction with this technology:

• Wire-Feed E-Beam Freeform Fabrication (MSC-23518-1)
• Vapor-Barrier Vacuum-Isolation System (LAR-17695-1)
• Method for Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes (LAR-17766-1)

If you would like more information or want to pursue transfer of this technology, please contact us by e-mail or phone: or (919) 249-0327.

For more information about other technology licensing and partnering opportunities with NASA’s Langley Research Center, please visit:

The Technology Gateway
NASA’s Langley Research Center
http://technologygateway.nasa.gov/index.cfm (link opens new browser window)