Numerical Modeling of Powder Flow During Coaxial Laser Direct Metal Deposition: Comparison Between Ti-6Al-4V Alloy and 316L Stainless Steel

S. Morville[1], M. Carin[1], D. Carron[1], P. Le Masson[1], M. Gharbi[2], P. Peyre[2], R. Fabbro[2]
[1]Université de Bretagne-Sud/UEB-LIMATB, Lorient, France
[2]PIMM, Arts et Métiers ParisTech, Paris, France

This paper presents a 3D numerical model to predict the whole process of coaxial powder flow, including the particle stream flow in and below the nozzle and also the laser-particle interaction process. The Particle Tracing Module of COMSOL Multiphysics is used to solve the coupled momentum transfer equations between the particle and gas phase while incorporating particle temperature evolution. A turbulence k-epsilon model is employed to describe the behavior of the gas flow. The trajectory of the discrete phase particle is calculated by integrating the force balance on each particle while taking into account gravity and drag forces. Heating of powder particles accounts for laser intensity, convection and radiation losses. The powder concentration and particle heating process are analyzed for two materials: Ti-6Al-4V alloy and 316L stainless steel. The influence of laser power distribution is analyzed. The numerical results are compared with experimental data.