Friction stir weld (FSW) inspections in aerospace manufacturing are challenging for ultrasound technicians not necessarily because they require specialized computations or complex techniques but because scanning with conventional probe setups can be so time consuming.
FSW is used for aluminum lap-joint and butt welds on many of the industry’s biggest aluminum alloy structures, from rocket boosters and fuel tanks on launch vehicles to fuselage panels and wings on airplanes. The process uses a machine to firmly clamp two workpieces together and press a rotating spindle into the joint line. It moves quickly along the seam, creating friction and heat that cause the adjacent metals to become plastic. They flow from the front of the tool to the trailing edge where the grains mix together and recrystallize to produce a strong, highly efficient bond.