Effect of Debinding Method and Sintering Atmosphere on Fused Filament Fabrication Printed 17-4PH Stainless Steel at Intermediate Sintering Temperatures

Fused filament fabrication (FFF) of 17-4PH stainless steel provides a cost-effective route for producing complex components, but the final properties strongly depend on debinding and sintering. Unsuitable conditions may cause incomplete binder removal, oxidation, and poor densification; thus, optimized debinding strategies and atmosphere selection are essential to balance strength, stiffness, and toughness. Existing studies on FFF 17-4PH limited, particularly regarding the comparative influence of debinding method, and sintering atmosphere. This study aimed to study solvent–thermal debinding combined with sintering at ~ 1100°C under argon and vacuum atmospheres. Characterization included dimensional and mass changes, microstructural evolution, and mechanical testing. Vacuum-sintered specimens exhibited 7–13% linear shrinkage, 74.4% relative density, and 25.6% porosity, achieving superior tensile performance: 112 GPa Young’s modulus, 40.6 MPa yield strength, 167 MPa ultimate strength, and 0.629 strain at break. By contrast, argon-sintered specimens showed only ~ 1% shrinkage, reduced density (55.7%), and higher porosity (44.3%), resulting in tensile properties nearly 25-fold lower. Load-bearing model predictions agreed with experiments with a correction factor of 1.426. Despite higher strength, vacuum-sintered specimens suffered toughness limitations due to voids and carbon-induced embrittlement, causing brittle fracture under impact. Conversely, argon-sintered specimens, though weaker, displayed more uniform porosity and reduced internal stresses, enabling better energy absorption during Charpy testing. These findings highlight a trade-off: thermal debinding alone is unsuitable for this filament, while combining solvent with controlled thermal profiling is recommended. Vacuum sintering improves strength and stiffness, whereas argon sintering enhances impact tolerance, emphasizing the importance of atmosphere selection.