Enhanced density and microstructural integrity of binder jetting manufactured ceramics through cold isostatic pressing

Binder jetting (BJ) is a type of additive manufacturing (AM) process that enables fabrication of complex zirconia (ZrO2) ceramic components. However, there are significant challenges in fabricating ceramic parts with high relative density and superior performance. In this study, cold isostatic pressing (CIP) process was integrated into BJ, successfully producing high-performance ZrO2 ceramics. Comprehensive study was conducted on ZrO2 granules, binder, and their interactions. In addition, effects of CIP process on relative density and mechanical properties of sintered samples were investigated. Results indicate that CIP process significantly enhances green body density and reduces spacing between particles, thereby facilitating subsequent densification during ceramic sintering. Moreover, debinding followed by CIP treatment yields superior mechanical properties compared to the methods where CIP was performed prior to debinding, as it prevents defect formation during debinding. Subsequently, differences in performance between ZrO2 ceramics treated with and without CIP were compared at various sintering temperatures. After sintering at 1400 degrees C, relative density and flexural strength of ZrO2 ceramics reached 98.75 +/- 0.19 % and 1047.80 +/- 88.45 MPa, representing significant improvements of 53.24 % and 100fold increase compared to those without CIP treatment, respectively. These findings indicate that proposed method is highly promising for fabrication of high-density and high-performance ZrO2 components.