Overcoming the penetration–saturation trade-off in binder jet additive manufacturing via rapid in situ curing

Binder jetting (BJ) enables the production of green parts for structurally complex ceramic, metal, or composite parts. However, the existence of a penetration–saturation trade-off (PSTO) in conventional BJ 3D printing hinders its development. Since an increase in saturation is often accompanied by an increase in penetration distance of binder (P), it is difficult to produce high strength and high precision green parts; this limitation is not conducive to the development of new material systems. To overcome this limitation, a methacrylate-based, thermally activated free radical polymerization system was used in this study as a binder to produce green parts under in situ curing conditions, created by increasing the temperature of the powder bed. The penetration of the powder bed by the binder is controlled by regulating its curing status during printing. The proposed rapid in situ curing printing process overcomes the PSTO associated with conventional BJ and can inform the optimization of binder formulation, equipment design, and binder jet printing. • Acrylate-based binder cures by thermally activated free radical polymerization. • The binder cures rapidly in a heated powder bed, limiting penetration distance. • In situ cured green parts demonstrate high dimensional accuracy and strength.