Droplet impact-induced molten pool dynamics and particle migration patterns during TIG-assisted droplet deposition manufacturing of SiC particle-reinforced Al–Si alloy

Abstract

A three-dimensional droplet-pool coupled model with dispersed phase was developed to simulate the TIG-assisted droplet deposition manufacturing (DDM) of silicon carbide (SiC) particle-reinforced aluminum (Al) matrix composites (AMCs), which was employed to calculate the surface morphology of the deposited layer, the thermal-flow fields and the distribution state of reinforcing particles in the molten pool. The cross-section profile of a single-track SiC-reinforced AMC deposit and the distribution state of reinforcements were examined and compared with the findings predicted by simulation, a good agreement was achieved. It is found that the falling Al droplet produces an obvious crater on the curved surface of molten pool. The viscous damping and simultaneous solidification are the main factors that dissipate the kinetic energy of the droplet. In addition, we discuss quantitatively how impact-induced thermodynamic within molten pool can change the migration behaviors and the distribution state of SiC reinforcement. The heterogeneous distribution of reinforcement particles can be attributed to the thermocapillary micro-convection and the velocity difference in the spreading and recoiling stages.