A basic study on the high power diode laser welding of a titanium alloy

High power diode lasers (HPDLs) have only recently been introduced for materials processing. The advantages of HPDLs include higher energy efficiency and lower running costs. Besides, because of the mass production possibility of semiconductors, the prices of HPDL are currently dropping fast, making these lasers very competitive for future largescale materials processing systems. This paper describes the application of High Power Diode Laser (HPDL), with maximum output power 2.3 kW and rectangular laser beam spot, for the welding of Ti6Al4V sheets, 1 and 1.5 mm thick. Bead on plate and butt welds were studied and tested using two different covering gases, He and Ar, and flow rates. A metallographic analysis of the crosssections of welded specimens was carried out in order to measure the morphological characteristics of the welded joint, micro-hardness and tensile tests were performed to complete the mechanical characterization. The results of tests showed that the shape of weld pool and mechanism of laser welding with a rectangular pattern of 808 nm laser radiation differs distinctly from other laser welding mechanisms, reported by the same authors in previous published works.