Robotic Nd:YAG Fiber Laser Welding of Ti-6Al-4V Alloy

摘要

In the present study, Ti6Al4V titanium alloy plates were joined using a robotic fiber laser welding method. The laser welding process was carried out at two different welding speeds. Effects of different heat input conditions on the microstructure and mechanical properties of robotic fiber laser welded joints were investigated. Some grain coarsening was observed in the microstructure of weld metal in samples joined using high heat input, compared to those using low heat input, and volume rates of primary α structures increased in the weld metal. The microstructure of weld metal in samples joined using low heat input was made of basket-weave or acicular α' grains and primary β grains in grain boundaries. Tensile and yield strength of samples joined using low heat input were higher than for those joined using high heat input, but their ductility was lower.