Material extrusion-based additive manufacturing of zirconia toughened alumina: Machinability, mechanical properties and biocompatibility

Material extrusion-based additive manufacturing (MEAM) has gained significant attention due to its versatile flexibility for fabricating a broad range of materials. In this study, fabrication of dense zirconia-toughened alumina (ZTA) ceramics with micro/nano powders of excellent mechanical and biological properties was investigated. The ZTA paste rheology was engineered to achieve appropriate rheological behavior. A novel machining scheme on MEAM produced ZTA green parts using CNC milling and high precision micro-milling was studied to investigate their effect on surface integrity and geometric accuracy. The MEAM produced ZTA ce-ramics show the highest relative density, Vickers hardness, bending strength, and fracture toughness of 99 %, 17.7 GPa, 422.5 MPa, and 6.2 MPa*m1/2, respectively. Biocompatibility of fabricated ZTA ceramics with different size of powders was investigated including cell adhesion, cell toxicity and cell proliferation, showing a good potential in biomedical usage. This framework provides a unique pathway for MEAM of ZTA ceramics to combine design and manufacturing freedom, multifunctionality, stability, and economical simultaneously.