Measurement of precision and quality characteristics of lattice structures in metal-based additive manufacturing using computer tomography analysis

Abstract

Additive manufacturing, especially lattice structure fabrication, has garnered interest for its potential in high-precision aerospace and medical applications. Due to porosity and dimensional variation, obtaining mechanical characteristics and accuracy remains a research priority. This study addresses the current knowledge gap by providing a comprehensive methodology for the qualitative evaluation of cellular structures in additive manufacturing, focusing on the critical parameters of relative density, dimensional deviations, and porosity characteristics. The research utilizes advanced μCT analysis to investigate the impact of these factors on the overall quality and functionality of printed objects, particularly in metallic lattice structures fabricated using Laser Powder Bed Fusion (LPBF) technology. The cell structures were constructed using MS1 tool steel as the material base. An extensive investigation was carried out on a diverse array of lattice configurations, including Body-Centered Cubic (BCC), Diamond, Fluorite, Kelvin, Schwarz, and Fischer – Koch. It was observed that discrepancies between actual and designed relative densities in structures such as BCC, Diamond, and Kelvin indicate densification attributable to the manufacturing process, particularly in smaller cell structures. Furthermore, global porosity analysis demonstrated a clear relationship between increased density and reduced porosity. Optimal manufacturing conditions for minimizing defects and enhancing the precision and quality of additive manufactured metallic lattice structures were identified as a cell size of 3 mm and a 50 % relative density.