Role of Binder Ductility in Enhancing the Green Body Integrity of Ceramic Vat Photopolymerization

Abstract

This study investigates the influence of photocurable acrylate binder mechanical properties on the fabrication of high-density zirconia ceramic parts via vat photopolymerization (VPP) to resolve persistent defects in green bodies by shifting focus from traditional slurry rheology to binder mechanics. By evaluating the transition from rigid to ductile acrylate binders in high-solid-loading zirconia VPP, the research focuses on the mechanical response of green bodies and validates performance through the assessment of relative density, hardness, and fracture toughness of sintered components. A critical trade-off was identified where binders with high neat mechanical strength led to early particle percolation and microcracking, whereas flexible binders created a pliable network that effectively dissipated internal stresses. Although flexible binders slightly reduced theoretical packing density by 5–10%, they enabled the production of defect-free zirconia parts sintered to 98% relative density, achieving a hardness of 13.4 GPa and fracture toughness of 4.8 MPa·m1/2. Ultimately, the study establishes binder flexibility rather than neat mechanical strength as the decisive design parameter for highly loaded suspensions, providing a validated framework for developing versatile binders suitable for both ceramic and metallic VPP systems.