In Situ Experiment for Laser Beam Welding of Ti Alloys Using High-Energy X-Rays
The laser beam welding (LBW) process has many advantages for industrial production; however, it still has to be optimized for two-phase Ti alloys. Phase transformations and residual stresses play a crucial role for welding these alloys. Specific questions about the development of phase content during fast heating with a laser and rapid cooling can only be addressed with time-resolved in-situ experiments, avoiding artefacts from quenching. Also the residual stress development during cooling depends on the occurring phase transformations. Thus, an LBW chamber employing a fibre laser was developed for use with high-energy X-rays from a synchrotron source. Bead-on-plate welding experiments with 2.5 mm thick samples were carried out at the HZG high-energy materials science beamline (HEMS) at DESY, Hamburg. The first experiments focused on the solid-solid phase transformations in a Ti-6Al-4V alloy. Moreover, residual stresses developing during cooling were studied.
Thomas Holden, Tamas Ungar, Thomas Buslaps and Thilo Pirling
P. Staron et al., "In Situ Experiment for Laser Beam Welding of Ti Alloys Using High-Energy X-Rays", Materials Science Forum, Vol. 905, pp. 114-119, 2017