Impact of ‘core-shell’ mode of printing on properties of 3D binderjet printed zirconia-alumina based bioceramics

Abstract

3D binderjet printing of bioceramics remained a major challenge, and powder specific-binder development and processing strategies still follow certain ‘black box’ approaches. In this study, for the first time, we report the efficacy of an acrylic based proprietary binder system to 3D print zirconia based bioceramics. Machine limited ‘core-shell’ mode of binder deposition resulted in heterogeneous distribution in particle arrangement from ‘shell’ to ‘core’, with higher binder saturation at the ‘shell’ region and less saturation at the ‘core’. A series of post-processing strategies like ‘presintering – salt infiltration – phase conversion – final sintering’, post-printing binder infiltration etc. were adapted to develop 3YSZ alone or together with ZrSiO4 or Al2O3, although with limited success. Despite poor strength properties (compressive/tensile/flexural), the acceptable strength reliability with modest Weibull modulus (m ​≈ ​5–9) was obtained in post-processed ceramics. While explaining the microstructure-property correlations, the contributions of different powder modification strategies and novel processing steps (‘dual powder deposition’ for non-macroporous powder bed) are discussed in particular reference to the porous architecture formed in 2D space or 3D volume, as investigated using SEM or micro-computed tomography.

Keywords

• 3D binderjet printing
• Zirconia alumina bioceramics
• Acrylic binder
• Core-shell saturation
• Micro-CT
• Weibull modulus