Identify the process

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Hi All,What's the process at 2:31, anyone?ThanksAndy
Reply:Tooling animation of FSW friction stir welding.  FSW is a solid state welding process used to join materials in the plastic state."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:http://blog.aws.org/welding-wonder-1/excerpt from above article....NASA and Lockheed Martin Engineers faced several difficulties as they learned to form, weld, and repair the new material. Myron Pessin, former Chief Engineer for the External Tank Program, noted that weld repairs were a significant challenge.Many weld lands on the Super Lightweight Tanks were increased in thickness by up to 0.35″ to allow more margin for potential weld repairs. A “second generation” of the Super Lightweight used a different alloy in the intertank thrust panels. The change allowed for even more weight savings – though they were offset by the conversion back to Al 2219 for the dome gores – which were easier to weld, and which drastically reduced repairs.With repair welds becoming more difficult to make, and production costs increasing on the tank, NASA began researching alternative welding techniques. Project Managers eventually chose the friction stir process, which produced a stronger joint than the fusion arc welding used in the earlier Lightweight Tank. Another significant benefit of friction stir welding was that it had far less elements to control. For example, in fusion welding you must control purge gas, voltage, amperage, wire feed, travel speed, shield gas, and arc gap. However, in friction stir there are only three process to control: rotation speed, travel speed, and pressure.Friction stir welding works by rotating a dowel between 180 to 300 revolutions per minute depending on the thickness of the material.  The tip of the dowel is forced into the material, and as it continues rotating, friction heat softens the area around the pin and forces it to forge and create a bond with the other material.