Solidification crack initiation and propagation in pulsed laser welding of wrought heat treatable aluminium alloy

Abstract

The effect of preheating on strain rate and liquid flowrate is analysed to develop a model for solidification cracking in successive laser weld spots in 2024 aluminium alloy. It is shown that the lower tendency for solidification cracking with preheating can be attributed to the lower strain rate but not the feeding rate. It is also shown there is a strong tendency for solidification crack propagation through the fusion lines between the consecutive weld spots where there is already a crack present at the fusion line. This observation can be attributed to the higher local strain rate and lower feeding rate.