In this study, the influence of pulse shaping on hot cracking susceptibility in pulsed Nd:YAG welding was investigated. The experimental results showed that it was possible to eliminate solidification cracking in AA 6082-T6 by using pulse shapes with a linear ramp down rate. The experimental investigations were supplemented by a numerical analysis. A two-dimensional axisymmetric thermal finite element model of pulsed laser beam welding was developed. The results showed that pulse shaping affects the thermal conditions during the weld pool solidification. These thermal changes result in coarser microstructure and therefore easier feeding of liquid in to the interdendritic cavities.

Topics
Laser beam welding, Finite-element analysis
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