Experimental and numerical analysis of solidification cracking behaviour in fibre laser welding of 6013 aluminium alloy

Abstract

Experimental observation and numerical modelling were employed to investigate the solidification cracking behaviour during fibre laser welding of 6013 aluminium alloy. The solidification cracking initiation location and propagation path were studied using a high speed camera system and via metallurgical analysis. A three-dimensional thermomechanical finite element model of fibre laser welding of aluminium alloys was developed, which considered cylindrical volumetric heat source, temperature dependent material properties, solidification shrinkage and stress relaxation in the weld molten pool. The transient evolution and distribution of mechanical strain in the brittle temperature range (BTR) were analysed in detail to find the factors which drove the crack initiation and propagation. The results showed that the solidification cracking initiated near the fusion line and then propagated along the centreline of the weld, which was the result of the strain distribution characteristic in BTR.

Joining Technologies for Aluminium Castings—A Review

“…In general, a high solidification/freezing range will cause a high susceptibility to hot cracking, and a high fraction of eutectic phase in the microstructure and a eutectic phase with sufficient wettability will result in a decreasing susceptibility to hot cracking [196]. Solidification cracking was observed to initiate near the fusion line, grow into the weld centre, and then propagate along the centreline of the weld when fibre laser welding of AA6013 was studied by Wang et al [197].…”