EXPANDABLE MANDREL FOR USE IN FRICTION STIR WELDING

摘要

A mandrel (72) that provides a counter-force to the pressure exerted on the outside of a pipe (90) or other arcuate surface by a friction stir welding tool, wherein the mandrel (72) is expandable through the use of a wedge (82), and wherein the mandrel (72) enables multiple friction stir welding heads to simultaneously perform welding on the arcuate surface.