| Abstract Scope |
Highly porous metal parts for filtration and biomedical applications are commonly manufactured from sintered powder precursors. Binder jet printing has the potential to develop in this area as porosity can be controlled through design, layering defects, and partial sintering. However, the porosity is limited by powder packing (~50%). Introduction of a space-holder to the metal powder feedstock allows to pack the powder during printing while retaining higher porosity after space-holder burn-out. In this study, Inconel 625 is used as a model alloy, together with poly-methyl methacrylate (PMMA) as powder space-holder. Different volume fractions of PMMA (0-70 vol.%) were sintered at various temperatures (1200-1290 °C). Their impact on porosity, pore size distribution, and connectivity were evaluated, along with part shrinkage, surface deformation, and permeability. Permeability measurements were performed with a falling head test on selected samples to observe the combined effect of space-holder addition and sintering on filtration potential. |