Analysis of Dendrite Formation under Laser Welding Conditions of Ti-6Al-4V Alloy and Removal through Annealing Conditions

This study investigates the microstructure and mechanical properties of Ti-6Al-4V alloys after laser welding and subsequent heat treatment. Core and ring beam laser welding was used, followed by mill annealing(MA) and beta annealing(BA). The microstructure analysis revealed that in the case of MA, α'-martensite transformed into Widmanst?tten α + β and α phases, with the base material exhibiting an equiaxed α + β phase. BA resulted in a consistent Widmanst?tten α + β phase throughout the entire structure. Hardness tests showed the highest values in the welding area, and decreased as it moved towards the base metal. BA completely eliminated the dendritic structure and achieved uniform mechanical properties, outperforming MA in both efficiency and material performance. BA was found to be the optimal heat treatment for dendritic removal.