Metal expansion joints manufacturing by a mechanically assisted laser forming hybrid method – concept

This paper presents the concept of metal expansion joints manufacturing using a mechanically assisted laserforming hybrid method. The metal expansion joints are made of a metal tube of an appropriate diameter and wall thickness with a combined bellow-lens shape. The concept assumes using a CO₂ laser to implement such expansion joints. The laser beam heats the selected area of the rotating tube, mounted on a swivel handle on one side and the actuator handle on the other end. After reaching the plasticising temperature, the actuator compresses the element. As a result, a bellow-lens shape is formed at the plasticization area. Initial experimental studies confirmed the validity of the concept. The bellow-lens metal expansion joint (type DN20) was obtained as a final result. The presented idea and the element manufacturing method were submitted to The Patent Office of RP.