Fuentek's Tech Transfer Blog

Defect Detection for Friction Stir Welding

FSW uses frictional heating combined with forging pressure to produce high-strength bonds virtually—but not completely—free of defects. (NASA photo)

If you are an expert in friction stir welding (FSW), this is an opportunity to contribute to the U.S. space program. But you must act quickly – by April 30, to be specific.

NASA’s Marshall Space Flight Center in Huntsville, Alabama is looking to improve its capabilities in detecting and managing critical defects in FSW. Specifically, Marshall is planning a study to better understand how flaws are created during different FSW processes and how they affect the welded material. Most importantly, they want to learn which faults are mission-critical, subsequently causing breach of pressure and catastrophic loss of the spacecraft.

In the past decade, due to the adoption of lightweight aluminum-lithium alloy combinations, as well as the high-strength bonds FSW produces without consumables or toxic fumes, NASA has begun using FSW in more of its construction. However, the technique is open to new and difficult-to-diagnose flaws in the welded materials. These defects include kissing bonds, where the welded components are in intimate contact but are not sufficiently welded, and sub-surface tears.

Through a Request for Information (RFI), Marshall is soliciting data from companies and experts in the field regarding the types of defects created by the three FSW processes NASA uses: self-reacting friction stir welding, conventional friction stir welding and friction plugs. The center is also interested in information on the methods of detecting and evaluating the extent of these defects on aluminum-lithium alloys, and methods of consistently creating specific defects so that methods to address them may be developed.

Interested in learning more or responding to this request? Contact Fuentek at (919) 249-0327 or

And check out our Web site for more opportunities to partner with NASA in collaborative R&D.