Formulation and Characterization of Stainless Steel-Based Feedstocks for Fused Deposition Modeling: Effects of Binder Composition on Rheology, Printability, Physical, and Mechanical Properties

This study investigates how feedstock composition affects the performance of 17-4 PH stainless steel (SS) parts produced by fused deposition modeling (FDM). Feedstocks consisted of 91–93 wt.% SS, with varying amounts of polyethylene glycol (PEG), paraffin wax (PW), and stearic acid (SA). Rheological analysis revealed shear-thinning behavior, with viscosity predominantly affected by PEG content at lower metal concentrations and increasingly governed by metal loading at higher concentrations. Thermal debinding confirmed that feedstocks with at least 91 wt.% metal and 3 wt.% PEG maintained structural integrity. Among tested formulations, 93 wt.% SS provided the best print quality, achieving 4.31 g/cm³ density, 1154 MPa flexural modulus, and 5.8 MPa flexural strength. Overall, the results highlight the importance of balancing metal and binder content for optimal FDM outcomes.