Direct ink writing of CeO2-based composite ceramics with enhanced mechanical properties and thermal conductivity

CeO 2 ceramics, renowned for their high temperature resistance and other exceptional properties, have shown great potential in industrial applications. However, the practical applicability of CeO 2 is constrained by conventional forming processes, which often fail to meet the demands for intricate structural designs due to the requirement for costly molds. The direct ink writing (DIW) technique provides an economical option for the rapid production of CeO 2 ceramics with complex structures. Nevertheless, the presence of dispersants and binders in the DIW ink will affect the sintering process, leading to reduced mechanical performance in the final products. Herein, a strategy for preparing CeO 2 -based composite ceramics incorporating Al 2 O 3 additive to enhance comprehensive performance via the DIW technique is presented. The study investigated the rheological behavior of the ceramic inks and the effects of Al 2 O 3 addition on the mechanical properties of the samples. The findings demonstrated that the inclusion of 0.05 wt.% PVP and 0.9 wt.% PVA effectively prevented particle agglomeration and endowed the ink with outstanding printability. Ceramics containing 10 wt.% Al 2 O 3 (M82A10P59) achieved the highest relative density, resulting in superior mechanical properties, with flexural strength, fracture toughness, and Vickers hardness reaching 155 MPa, 4.60 MPa·m 1/2 , and 5.76 GPa, respectively. Notably, thermal conductivity values of M82A10P59 samples were 9.8021 W·m -1 ·K -1 , 6.9925 W·m -1 ·K -1 , and 6.2783 W·m -1 ·K -1 between 100 °C and 300 °C, surpassing those of pure CeO 2 . This work offers promising approaches to fabricating innovative and complex structures of high-performance CeO 2 ceramics for industrial applications.