Three dimensional analytical and finite element methods for simulating a moving melt pool with mass addition

Laser Direct Metal Deposition, alloying and similar additive processes are recognised as difficult to model because of the complicated mass and heat flow. This paper compares analytical and finite element approaches via a case study of the coaxial laser direct metal deposition of Inconel 718. The analytical models used are based on superposition of the quasi-stationary temperature fields of multiple moving heat sources, modified to account for the incoming mass. The finite element models used are based on element birth methods and utilize the anisotropic enhanced thermal conductivity method. The simulations are compared with experimentally results and results show that both methods can predict depth more accurately than width. The analytical method generally underestimates width and the finite element method overestimates it. The model inaccuracies can be explained in part by considering the increased effective conductivity within the melt pool.