Numerical Modeling of Metal-Based Additive Manufacturing Using Level Set Methods

Abstract

The advance in computational science and engineering allows people to simulate the additive manufacturing (AM) process at high fidelity, which has turned out to be a valid way to model, predict, and even design the AM processes. In this paper, we propose a new method to simulate the melting process of metal powder-based AM. The governing physics is described using partial differential equations for heat transfer and Laminar flow. Level set methods are applied to track the free surface motion of the molten metal flow. Some fundamental issues in the metal-based AM process, including free surface evolution, phase transitions, and velocity field calculation, are explored, which help us gain insight into the metal-based AM process. The convergence problem is also examined to improve the efficiency in solving this multiphysics problem.

Computational modelling of process–structure–property–performance relationships in metal additive manufacturing: a review

“…For pure powders, the specific heat capacity of the powder beds can be identified from the powder bulk density, and for powder mixtures, it can be obtained from the law of Kopp-Neumann [93]. The material in the powder form has a different specific heat capacity than that in the solid form [94,95]. In contrast, the same value of specific heat capacity is assumed for both solid and powder forms for reducing the computational cost, time, and memory needed for the numerical modelling of AM processes [96].…”

“…In this approach, when a molten pool stability analysis is carried out, the specific heat capacity is defined for both solid and liquid phases [87,88,94]. Material density, as a temperature-dependent property, changes during the process, and at most times, the density of the final part is higher than the powder bed density [68,95]. However, in several studies, the density has been considered to be constant, to decrease the complexity of the analysis [98].…”