Dimensional Accuracy of Compressive Specimens Obtained by SLS Technology

Abstract

The objective of this study is to examine the accuracy of dimensional measurements for parts produced using Additive Manufacturing (AM) technology. The specific 3D printer employed in this research is Fuse 1 (FormLabs, Summerville, MA). The printer operates on the Selective Laser Sintering (SLS) method, enabling the simultaneous creation of objects with diverse shapes and sizes, as long as they are printed at a minimum separation distance of 5 mm. The printing process involved a layer thickness of 110 microns. To assess the dimensional accuracy, a particular type of specimen adhering to the ISO 604 standard for compressive specimens was analyzed. These compressive specimens possess dimensions of Ø10 × 20 mm. Four sets of specimens were fabricated, differing in their printing orientation (horizontal or vertical) and printing location (edge or middle of the powder bed). Polyamide (PA 12) was the chosen material for printing the specimens, known to exhibit compressive strength values of 13/24/55 MPa at 1%/2%/5% strain, respectively. After printing, the specimens were subjected to a 3D scanner Atos Core 200. The most significant deviations observed across all four series of specimens were primarily in terms of height, ranging from 0.1 to 0.15 mm. In the case of vertically printed specimens positioned in the middle of the powder bed, variations in the width of the specimens were also noted.