Numerical Investigation of Transient Temperature Distribution during Ti-6Al-4V Selective Laser Melting

The transient temperature field in the powder bed has a crucial effect on the quality of parts fabricated using Selective Laser Melting(SLM). In this study, a finite element model is established regarding the variance of temperature-dependent thermal properties and transformation latent heat. The temperature distribution and melt pool dimensions of a laser scan track were obtained by varying multiple parameters(layer thickness, laser power and scan speed). The effects of transition of material state and heat source model are also analyzed in this paper. The finite element simulation results show that an increased laser power and/or decreased scan speed results in an elevated maximum temperature of the powder layer and a larger melt pool size. Furthermore, it is found that the maximum temperature is significantly lowered due to the heat diffusion into the previous sintered zone. The heat source model has to be selected properly according to the element size.