Evolution and convection mechanism of the melt pool formed by V-groove laser cladding

Abstract In comparison to planar-oriented laser cladding, non-planar laser cladding also deserves to be discussed. A numerical model of non-planar laser cladding was constructed for V-grooves with different tension angles. The simulation results show that the melt pool generated at the bottom of the V-groove undergoes an oscillatory expansion phase similar to that of planar laser cladding and ends up in a periodic steady state. As the tension angle θ of the V-groove decreases, the absorption of laser energy by the bevels on both sides becomes more and more, and the melt pool volume starts to decrease. However, after θ is reduced to a certain threshold, the melt pool volume starts to become larger instead, and this change brings about a complex melt pool convection pattern. Finally, the mechanism of cavitation generation at the bottom of the V-groove when θ is less than 60° and the possible avoidance measures are also analyzed.