Studies on the role of total welding rotation in friction welding of tube-to- tube plate using an external tool

摘要

Friction welding of tube-to-tube plate using external tool (FWTPET)(1) is an innovative friction welding process wherein a friction stir welding tool is used to join tube and tube plate. This work investigates the combined effects of tool rotation speed and plunge duration in terms of a parameter named Total Welding Rotation (TWR)(2), on the quality of FWTPET joints. A mathematical model is proposed to understand the upper and lower limits of TWR, beyond which the process is inclined to give defective joints. This model is verified using experimental studies on joints between AA6061 plate and AA1060 tube. The welded specimens are non-destructively evaluated using Digital Radiography (DR)(3) and Phased Array Ultrasonic Testing (PAUT)(4), which show that above and below certain TWR values the process leads to defective joints.