Evolution of High Temperature Metal Molten Pool Based on VOSET Method

The study of the evolution phenomena of the melt pool during additive manufacturing (AM) process is a hot topic in current. However, due to too much model simplification and an imprecise interface capture in the numerical study of the melt pool, the forecast precision is relatively low. In order to improve the accuracy of predication, a VOSET interface capture method is introduced and based on which a numerical metal melt pool model is established. Meanwhile, the corresponding experimental studies are carried out for validation. At last, the basic evolution phenomena and its formation mechanisms of the melt pool are clearly revealed. The main results are drawn. During the laser deposition on metal surface, tangential Marangoni convection is induced by a sharp rise in temperature gradient, the convection effect increases rapidly and gradually dominates the evolution of melt pool. Both of the deformation of the free surface and the size of melt pool increase rapidly, and the tangential evolution is more vigorous. After a while, the heat deposition and dissipation in melt pool are dynamically balanced, and the melt pool evolution enters a quasi-steady state.