Design of a debinding process for polymetallic material green parts fabricated via metal paste injection 3D printing with dual nozzles

Debinding is one of the most critical processes in metal paste injection 3D printing technology (MPI). In order to design the optimal debinding parameters, the debinding temperature, debinding time and heating rate were discussed from the perspective of dynamics. The results showed that there was a peak in liquid phase mass transfer during debinding, exhibiting the characteristics of migration with debinding temperatures. For gas phase mass transfer, when the temperature was 300 °C, the thermal debinding diffusion coefficient was the largest (9.7 × 10−5 cm2 s−1) and the corresponding debinding time was 3.5 h. By analyzing the activation energy of the debinding reaction, when the heating rate was 10 °C min−1, the activation energy required for the thermal debinding reaction was the smallest. Combined with the sintering process, the interwoven structural parts of the copper and cupronickel components were finally obtained. The average hardness of the polymetallic parts was 78.8 HV, and the density was 8.1 g cm−3.