Using forging pressure combined with intense frictional heating, a cutting edge manufacturing process known as friction stir welding transforms metal from a solid into a nearly plastic shape. Once a rotating pin is used to soften and stir the metal, a bond can be created between two metal plates that’s free of defects, uniform, and incredibly strong. The technology behind friction stir welding is considered a signature feature and vital component of next generation shuttle systems and other space hardware.
In the 1990s, an aluminum lithium alloy was used to create external tanks, since at the time, this was the material that best fit requirements for light weight and high durability. But unfortunately, the new alloy was expensive and very difficult to weld. Friction stir welding, a new and experimental process at that time, was used on the space shuttle external tanks that were designed to hold propellant for the main engine. The process worked well, and was not only easy, reliable, and defect free, but also cost effective.
The first friction stir welded tanks were created in 2001 and flew and 2009. Since that time, the process has been applied to an increasingly wide range of aerospace hardware and is now considered a crucial technology for the future of hardware fabrication.
Metals joined by friction stir welding are considered more reliable, predictable, more environmentally friendly, and safer than those joined by older methods. The process is also more efficient than standard fusion arc welding, since it requires a lower number of weld passes, and it’s expected to significantly cut back the release of welding fumes, high voltage and radiation.
At this point, the Boeing company has been contracted by NASA to develop an SLS core and upper stage using friction stir welding, for a finished core that will store liquid hydrogen and oxygen and will stand over 200 feet tall. This equipment will be manufactured at a plant in New Orleans using one of the largest friction stir welding robotic systems in the world.
Boeing and NASA both believe that this new welding technology will leverage the benefits of existing processes while taking advantage of promising new innovations. For more information about friction stir welding and the impact this process may have on modern manufacturing techniques, contact the Little Rock staffing and business information experts at CSS.