LAUSR

Abstract Prevention of solidification cracking is a major concern in pulsed laser welding of aluminium-magnesium alloys. Laser parameters can affect both Mg evaporation and the solidification rate. In this study the interactive effects of Mg evaporation and solidification rate on solidification cracking susceptibility (SCS) is investigated. It is shown that due to the rapid solidification of Al-Mg alloys in pulsed laser welding, SCS increases and the maximum cracking susceptibility occurs at alloy with higher Mg composition in comparison to a casting process. Hence, the range of the composition susceptible to solidification cracking is expanded. The calculations on Al –Mg alloy 5083 showed that when the laser pulse frequency is increased, SCS is decreased due to reductions in the solidification rate. On the other hand, by increasing laser pulse frequency due to successive evaporations, the Mg concentration of the final weld metal is decreased, and that increases SCS. However, interactive analysis of SCS shows that the effect of decrease in solidification rate is more pronounced than the effect of the decrease in the Mg content of weld metal on SCS.