Effect of Different Powder Bed Thermal Conductivity Models on the Melt Pool Characteristics and Solidification Parameters during Laser Powder Bed Fusion of Ti6Al4V.

Artificial material properties assignment is usually adopted in the computational modelling of laser powder bed fusion (LPBF) process to obtain better agreement between the simulated and experimental results. In this context, various mathematical models are used in the literature to calculate the thermal conductivity of the powder bed in the continuous domain computational analysis of the LPBF process for metallic materials like Ti6Al4V, irrespective of the impact they have on the melt pool thermo-hydrodynamics and solidification parameters. In this study, a comparison of two different powder bed thermal conductivity models—linear and power law, was conducted. Computational analyses were conducted using each of the two models for powder bed thermal conductivity, and the melt pool dimensions, temperature field and solidification parameters were calculated and compared. It was seen that the power law model resulted in slightly larger melt pool dimensions with higher temperatures and solidification parameters, compared to the linear model for the powder bed thermal conductivity. The present study shows that the arbitrary assignment of material properties during computational analysis of LPBF process may lead to widely different results. [ABSTRACT FROM AUTHOR]