Experimental study of effect of infill density on tensile and flexural strength of 3D printed parts

Abstract

Additive manufacturing (AM) is an innovative procedure that can quickly create complex structures. By layering a material, a three-dimensional object is created using this technique. Every deposit of liquefied or partly liquefied material abides by the previous deposit. Fused deposition modelling’s (FDM) objective is to comprehend how varied interior structures influence the bending resistance of the printed samples and to investigate the impact of various infill patterns and percentages. The term “infill” describes the pattern of solid material used to fill a 3D-printed object's interior. It is utilized to give the printed part structural support and strength. Acrylonitrile butadiene styrene (ABS) material was chosen for this study as it offers a greater and superior finished plane along with dimensional stability. The infill pattern chosen for the flexural test study was the triangular pattern which includes different densities of infill percentages precisely, 25%, 50%, 75%, and 100%. A few specimens of ABS material having 100% infill density are put through a tensile test according to the ASTM D638. The ASTM D790 standard was used to make a model and test the flexural strength of the specimen. Line and triangle patterns provided the most ideal tensile and bending strength properties. This is likely because the deposited rasters are associated with the direction of loading. For line patterns with 100% infill, scanning electron microscopy (SEM) analysis showed a convincing connection between the microstructures and the rasters (porosity, voids, gap between beads and hole due to polymer pulled out). Furthermore, SEM analysis showed matrix failure and significant voids in a triangular pattern at infill densities of 25%, 50%, 75%, and 100%.