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 ceramics 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.