Dispersion of reinforcing micro-particles in the laser welding of metal matrix composites: High-fidelity modeling with experimental characterization

Understanding the interaction mechanism between keyhole, solid phase (ceramic particles), and liquid phase (metal matrix) will offer key insights into laser welding/additive preparation of high-performance metal matrix composites. The laminar SiC particle-reinforced Al matrix composite, which is extensively used in aviation structural parts, is utilized as the experimental model. The effect of the keyhole mode on the migration behavior of SiC particles in the weld pool was revealed by simulating the multiphysical thermal fluid flow during the laserwelding process. The simulation results revealed that the flow of the molten pool and the keyhole mode have significant effects on the migration behavior of particles. The variation of keyhole mode leads to considerable changes in molten pool dynamics and corresponding SiC particle distributions in the molten pool. The observed selective distribution of SiC particles is due to the flow characteristics of the molten pool. In addition, results showed that the keyhole mode can maximize the uniform distribution of SiC particles in the melt pool, thereby addressing the nonuniformity problem of SiC particles. This work is a fundamental advancement in the modeling of laser-welded SiC particle-reinforced Al matrix composites and provides unprecedented details on the effects of keyhole patterns on weld pool dynamics. This work can further offer practical guidance for "temperature field-regulating reaction behavior" and "velocity field-regulating distribution behavior."