Thermal Modeling of Laser Based Additive Manufacturing Processes within Common Materials

Abstract

Process optimization is an important area requiring further research in the field of rapid prototyping and manufacturing. Current research efforts are focused on enhancing metallic powder bed additive manufacturing processes such as Laser Melting and Electron Beam Melting (EBM). Optimizing this class of manufacturing processes can lead to revolutionary changes in part quality and repeatability. Modeling and simulation can be used as a facilitating tool to predict the behavior of materials and processes and alleviate the need for extensive random experiments. This paper presents finite element simulation of thermal modeling thermal modeling of laser melting process to determine the melt pool geometry and temperature distribution in powder bed. This model was used to compare these characteristics between commonly used powder materials to include Ti6Al4V, Stainless Steel 316L, and 7075 Aluminum powders. Initially, a common set of parameters were used for all materials and it was found that melt pool could not be sustained in aluminum and steel and only titanium process resulted deep and complete melting and solidification. Optimized process parameter sets are suggested to develop consistent melt pools throughout the build process for aluminum and steel. It was discovered that steel powder beds require higher beam power than titanium powder beds to establish a consistent melt pool. Aluminum powder beds need higher beam power than both titanium and steel powder beds and also require a reduced scan speed to maintain a consistent melt pool.