Fused Filament Fabrication Additive Manufacturing of 17-4 PH Stainless Steel: Process–Structure–Property Relationships in Magnetic Materials

Abstract

Additive manufacturing (AM) enables the fabrication of complex metallic components through layer-by-layer processing directly from digital models. Among AM techniques, material extrusion–based processes such as fused filament fabrication (FFF) provide an accessible method for producing metal parts using filament feedstocks composed of metal powders and polymer binders. When applied to precipitation-hardening stainless steels such as 17-4 PH, the processing route and heat treatments can influence the resulting microstructure and functional properties. This work investigates the magnetic behavior of 17-4 PH stainless steel fabricated using FFF and evaluates how heat treatment conditions influence measured magnetic properties. Samples were produced and analyzed under multiple conditions, including the as-printed state and aging treatments of H900, H1025, and H1150. Magnetic properties were characterized using vibrating sample magnetometry (VSM), with coercivity (𝐻𝑐) and saturation magnetization (𝑀𝑠) used as primary metrics for comparison across samples. Phase analysis was performed using X-ray diffraction (XRD) to examine the crystalline structure and identify dominant phases present after processing and heat treatment. The results describe how coercivity and saturation magnetization vary across samples and heat treatment conditions. The as-printed samples exhibited soft ferromagnetic behavior, with a mean coercivity of approximately 5.64 Oe and a mean saturation magnetization of approximately 152.77 emu/g. Heat treatment had a stronger influence on the magnetic response, with the H900 condition increasing mean coercivity to approximately 43.91 Oe and the H1150 condition reducing mean saturation magnetization to approximately 144.86 emu/g. Together, magnetic and phase characterization clarify the magnetic response of FFF-fabricated 17-4 PH stainless steel.