OUT OF POSITION FRICTION STIR WELDING OF CASING AND SMALL DIAMETER TUBING OR PIPE

摘要

A system for friction stir welding small diameter tubing, where the tubing is held in a correct position and can be rotated by the positioning and holding system while a FSW tool is held stationary, or vice versa. Internal mandrels are also described which can fit inside the smaller dimensions of the small diameter tubing and expand to provide a counter force to prevent deformation of the tubing when forces are applied by the FSW tool, A new FSW tool enables the FSW tool to direct more heat on a tool/workpiece interface to counteract a lack of contact between the FSW shoulder and the workpiece because of tube curvature. The FSW tool is positioned on a small diameter tube by trailing the joint to provide desirable heating at the joint/workpiece interface and surface finishing.