Theoretical and experimental investigations on laser hybrid wire ARC additive manufacturing

Abstract

Wire arc additive manufacturing (WAAM) is one of the metal additive manufacturing method in which rapid fabrication is possible for components of big size. A significant amount of heat energy is transferred to the work piece during this process, with defined idle period between each deposition layer so that the workpiece cools down during the subsequent layer deposition. This variable cooling rate technique keeps the workpiece from collapsing and maintains a proper inter-pass temperature. The main challenge is to choose an inter-pass ambient cooling time to mitigate the residual stresses induced in the workpiece. The optimum inter-pass cooling time can be outlined by employing experimental and computational iterations. However, before experimental iterations, the material’s thermal and mechanical behaviour were investigated using finite element analysis, by introducing DFLUX SUBROUTINE within ABAQUS 6.20 SOFTWARE. The simulation results were analysed and the optimum inter-pass cooling time obtained was 800 sec. These optimized parameters are used for WAAM based 10 Layers stack deposition. The WAAM model developed is also used for preheating thing with mild modifications to observe the change in residual stress. Uniaxial compression test simulation and experiment is done to observe the compressive strength of the experimental samples with various cooling time and pre-heating.