3D Printing by Selective Activation of Geopolymer-Based Binders

The powder bed-based technique of selective activation, combined with proper material formulations, can effectively address challenges related to over-hanging parts and intricate detailing in additive manufacturing with mineral-based materials. While there is extensive research on cement-based materials, a notable gap remains in understanding geopolymer-based materials in the context of addi-tive manufacturing. This investigation focuses on the material parameter aspect with respect to printability performance, presenting a novel perspective.
Geopolymer binders require further investigation to establish a comprehensive understanding on the correlation between various material and printing parame-ters. On the side of metakaolin-based binder, gap-graded particle gradation is con-sidered to study their effect on dimensional accuracy in relation to the activating agent used. A single layer analysis is conducted to investigate the interrelations between the material and printing parameters. In particular, this study aims to comprehensively investigate the influence of several key printing parameters, in-cluding feed height (FH), layer height (LH), and the orientation of specimens rela-tive to the print head along with loading direction, on both the mechanical prop-erties and dimensional accuracy of printed parts. By systematically varying these factors and conducting thorough analyses, the research elucidates their individual and collective impacts on the performance and quality of printed components. Additionally, quantitative analysis of the powder bed features are performed using microscopy. The study aims to crease a base for producing facade elements and load-bearing elements with geopolymer binder in the near future.