In situ 4D tomography image analysis framework to follow sintering within 3D-printed glass scaffolds.

Achintha I Kondarage,Nuwan D Nanayakkara,Gowsihan Poologasundarampillai,Thilina D Lalitharatne,Julian R Jones,Angelo Karunaratne,Amy Nommeots‐Nomm,Peter D Lee

doi:10.1111/jace.18182

Abstract

We propose a novel image analysis framework to automate analysis of X‐ray microtomography images of sintering ceramics and glasses, using open‐source toolkits and machine learning. Additive manufacturing (AM) of glasses and ceramics usually requires sintering of green bodies. Sintering causes shrinkage, which presents a challenge for controlling the metrology of the final architecture. Therefore, being able to monitor sintering in 3D over time (termed 4D) is important when developing new porous ceramics or glasses. Synchrotron X‐ray tomographic imaging allows in situ, real‐time capture of the sintering process at both micro and macro scales using a furnace rig, facilitating 4D quantitative analysis of the process. The proposed image analysis framework is capable of tracking and quantifying the densification of glass or ceramic particles within multiple volumes of interest (VOIs) along with structural changes over time using 4D image data. The framework is demonstrated by 4D quantitative analysis of bioactive glass ICIE16 within a 3D‐printed scaffold. Here, densification of glass particles within 3 VOIs were tracked and quantified along with diameter change of struts and interstrut pore size over the 3D image series, delivering new insights on the sintering mechanism of ICIE16 bioactive glass particles in both micro and macro scales.

Highlights

Additive manufacturing (AM) allows the fabrication of customized porous architectures with complex geometries and interconnected pores
We propose a new automated image analysis framework to analyze micro- and macrostructural changes that occur in AM bioceramic scaffolds using 4D image data solving image analysis challenges such as tracking volumes of interest (VOIs) and accurate segmentation of glassy phase
Image analysis plays a vital role in the characterization of dynamic processes using 4D imaging

Summary

Introduction

Additive manufacturing (AM) allows the fabrication of customized porous architectures with complex geometries and interconnected pores. Various AM technologies have been used to fabricate porous ceramic structures, including selective laser sintering (SLS),[10,11] selective laser melting (SLM),[12,13] stereolithography (SLA),[14,15] fused deposition modeling (FDM),[16,17,18,19] inkjet printing (IJP),[20,21] binder-based 3D-printing (3DP),[22,23,24] and Direct Ink Writing (DIW).[25,26,27] In most of these techniques, ceramic particles mixed with a binder are printed into a green body scaffold and sintered to obtain a fully densified scaffold, which results in shrinkage of the structure.[1,22,26]

Methods

Results

Conclusion