Numerical simulation of dynamic analysis of molten pool in the process of direct energy deposition

Abstract

Laser direct energy deposition (L-DED) can improve the forming efficiency of parts by controlling laser power, scanning speed, powder flow rate, and spot size. It is a good way to complete the processing and repair of complex parts. In this paper, a three-dimensional numerical model is established to study the dynamic cladding process (pool geometry, energy transfer, and dynamic solidification) of Inconel718 alloy during direct energy deposition. The fluid of volume (VOF) method is used to track the free surface of the melt pool, and the powder source model is established by discrete method. The results show that the molten pool size (area, width, height, depth) of the model is relatively uniform and can predict the shape of the molten pool well. The energy transfer in the molten pool is disturbed to some extent by the metal powder flow. The temperature gradient and cooling rate of the cladding layer are relatively large near the mushy area during the solidification process.