Effect of filler metal feed rate and composition on microstructure and mechanical properties of fibre laser welded AA 2024-T3

Prediction and measurement of residual stresses and distortions in fibre laser welded Ti-6Al-4V considering phase transformation

“…The unit cell volume for each phase was determined from the real time in-situ synchrotron X-ray diffraction measurements of the lattice parameters of the α and β phases during heating of Ti-6Al-4V by Elmer et al [34]. The lattice parameters were measured from the bcc {110} reflection for β phase and hcp {101} reflection for α phase and the volume of α phase was calculated using a0 2 csin60° assuming c/a = 1.5963 and a0 3 for β phase as shown in Figure 7. The volumetric strains during phase transformation due to the differences in unit cell volumes between these two phases was therefore calculated by multiplying the volume fraction of each phase in the microstructure by its respective unit cell volume as a function of temperature during welding.…”

“…A good understanding of the welding process and information about residual stresses and distortions in welded components are of great interests for quality control and improvement of structural performance of integral structures so that in service failures can be avoided [3]. It is therefore, important to investigate the effect of residual stress and distortion on the structural performance and mechanical properties of the welded joints such as the tensile, fracture and fatigue behaviour and reduce them to acceptable levels by using optimised welding parameters, joint geometry and well characterised welding procedures [3].…”

“…It is therefore, important to investigate the effect of residual stress and distortion on the structural performance and mechanical properties of the welded joints such as the tensile, fracture and fatigue behaviour and reduce them to acceptable levels by using optimised welding parameters, joint geometry and well characterised welding procedures [3]. Determination of residual stresses and distortions by experimental measurements is complex, expensive, time consuming and requires significant amount of resources.…”

The effect of Ar and He shielding gas on fibre laser weld shape and microstructure in AA 2024-T3

“…Recently, Ahn et al [11,12] and Chen et al [13] investigated the effect of varying filler metal feed rate on weld pool chemical composition and the resulting hot crack sensitivity and porosity formation of fibre laser welded 3 mm thick AA 2024-T3. It was found that micro hot cracks and porosities were reduced by diluting the weld pool with less than 0.6% silicon content so that the fraction of Mg2Si, the solidification temperature and total shrinkage during freezing all decreased.…”

“…As fibre laser welding of AA 2024-T3 is relatively untested and unproven, investigations still need to be conducted to study the properties and performance of fibre laser welded AA 2024-T3, optimise the welding procedure and processing parameters to consistently produce high quality welds with no welding defects and with good mechanical properties [11].…”