Abstract
The objective of this work is to study, through a simple test, the influence of process parameters on microstructure and mechanical loading in order to minimize hot cracking risk. An original test was developed, consisting of applying a controlled tensile preload in the welding direction on a thin sheet of 6061 aluminum alloy, before making a fusion line with TIG process. Microstructure soldification analysis has permit to identify characteristic lengths reflecting process parameters influence on grains morphology. Microstructure modeling, using data from thermal simulation, has allowed to predict microstructure obtained in different welding conditions. Hot cracking criterion is applied on the predicted microstructure and show grains morphology influence on crack initiation. To end, solutions to optimize welding process, with respect to hot cracking phenomenon, are proposed taking into account the process / material interaction.