The influence of Volumetric Energy Density on the mechanical behavior of PA12 parts produced by Powder Bed Fusion: An experimental and numerical study

Abstract

Powder Bed Fusion (PBF) consists of a widely used and very promising Additive Manufacturing (AM) method, which is typically employed in the process of polymer and polymer-based materials. Polyamide 12 (PA12), due to its inherent properties, finds several applications in various industries, including aerospace, medical and automotive, while it is the most commonly applied polymer for this PBF AM method. It has been proved that the SLS process parameters directly and strongly impact the mechanical properties of the fabricated parts, and although significant research has been carried out in the relevant field, the optimization and the in-depth understanding of the process is still an active research topic. In the current research article, an experimental and numerical study regarding the PBFFF of PA12 is presented with the main aim investigation of how different Volumetric Energy Densities (VEDs) affect the process, as well as the impact of the process parameters combination (i.e., different Laser Power and Laser Scanning Speed) on the quality of the print, even if the VED is kept constant. The quality of the process was assessed based on the printed specimens' tensile properties, whilst a modeling methodology that considers overheating and degradation phenomena are presented. From the simulation of the process, it is deduced and explained the non-linear behavior of the process. The experimental results indicate a threshold VED and some favorable parameter combinations that significantly increase mechanical properties.