Effect of the Process Parameters on the Geometrical Defects of Ti-6Al-4V Hot Rolled Sheets Laser Beam Welded

Abstract

Ti-6Al-4V is an alloy that is increasingly used in aeronautics due to its high mechanical properties coupled with the lightness. An effective technology used to manufacture titanium components with a reduced buy to fly ratio is the laser beam welding. Previous studies showed that the key factor that rules the mechanical properties and the fatigue life of the joint is its morphology. The aim of this paper was to investigate the influence of the main process parameters, such as welding speed and laser power, on the geometrical features of the joint, in terms of undercut, underfill, reinforcement and so on. 3.0 mm thick Ti-6Al-4V rolled sheets were welded in butt joint configuration by using a Nd-YAG laser source. The joint performances were studied in terms of weld morphology, microstructure and Vickers microhardness. Then, defects such as underfill and reinforcement, controlling the whole weld morphology, were observed, and the relationship between the occurrence, the entity of these defects and the process parameters was studied.

Numerical Simulations and Experimental Validation on LBW Bead Profiles of Ti-6Al-4V Alloy

“…Cai et al (2017) have used pure Ti-filler with laser to improve the welding properties of γ-Ti-Al alloy. Boccarusso et al (2015) have examined the influence of LBW parameters on defects in Ti-6Al-4V hot rolled sheets. Junaid et al (2017) have performed pulsating laser welding of Ti-5Al-2.5Sn alloy to examine the effect of LBW parameters on weld pool shape, pulse overlap, oxide formation and microstructure (using Scanning Electron Microscope (SEM) and Optical Microscope (OM)).…”