NASA Engineer
HUNTSVILLE, Alabama — Twenty years ago, it was a revolutionary idea for welding metal together. Ten years later, it was critical technology for America’s space shuttle.
Today, the technology called “friction stir welding” is widely used to join aluminum alloy components – particularly in the transportation field where alloys save weight and weight costs money.
“Anything light that travels – trains, boats, cars, planes,” explained Jonathan Martin of The Welding Institute of Cambridge, England.
Martin is organizer of an international friction stir welding conference that opened Tuesday at the Von Braun Center. About 250 scientists and engineers from 22 countries will spend the week learning new developments in tool design, modeling and other aspects of the welding technique.
Marshall Space Flight Center Acting Director Gene Goldman addressed the conference Tuesday, which concludes Friday with a tour of Marshall’s high-bay welding facility.
That facility is where NASA is developing and testing welding techniques for assembling the core section of its upcoming heavy-lift rocket.
Tuesday morning, NASA friction stir welding expert Jon Street and Greg Riddle, lead engineer for Boeing’s stir-welding team in Huntsville, gave an early tour of the facility.
Friction stir welding joins pieces of metal together by a deceptively simple technique. Patented clamps – key to the operation – hold the plates together while a rotating steel rod penetrates the plates at the seam and moves along the seam “stirring” the plates together. The two plates aren’t melted together but they are fused in a way that creates a joint of incredible strength and flexibility.
“No filler wire, and no gas,” Street said, to mention just two of the advantages over traditional fusion arc welding techniques.
Goldman told the conference that the technique, which NASA adapted and used for the first time in 1995, saved money and increased quality in the production of space shuttle external tanks.
The technique “had high reliability, a low number of defects and gave us a practically perfect weld,” Goldman summarized.
NASA’s facility at Marshall has developed the technique so well now that commercial space companies such as SpaceX, Blue Origin, Lockheed, Dynetics and Aerojet are following its work.
For NASA, friction stir welding’s next big challenge is assembling the core fuel tanks for the heavy-lift rocket that flies for the first time in 2014.
Riddle and Street are working together with teams of scientists and technicians to meet that tight deadline.
“We’ll get there,” Riddle said, thanks in large part to friction stir welding.
