Rigorous emission regulations call for more efficient passive control catalysts for exhaust gas aftertreatment without affecting the internal combustion process and CO2 emissions. Although the state-of-art ceramic honeycomb substrate designs provide high surface area and a degree of flexibility for heat and mass transfer adaptations, additional emission reduction benefits can be achieved when more flexible designs to provide effective thermal management are introduced. The conventional cordierite honeycomb substrates are manufactured by extrusion; therefore, only substrates with straight channels can be fabricated. This study aims to highlight any design limitations of conventional substrates by employing additive manufacturing as the main method of manufacturing diamond lattice structures using DLP (digital light processing) technology. Both conventional substrates and diamond lattice structures are studied numerically and experimentally for flow through resistance and temperature distribution. Numerical predictions and experimental results showed good agreement. The results show the increase of the axial temperature distribution for diamond lattice structures and a significant decrease of the pressure drop (38–45%) in comparison with the benchmark honeycomb with similar surface area.

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Digital Light Processing (DLP) technology exhibits the capability of producing components with complex structures for a variety of technical applications. Postprocessing of additively printed ceramic components has been shown to be an important step in determining the final product resolution and mechanical qualities, particularly with regard to distortions and resultant density. The goal of this research is to study the sintering process parameters to create a nearly fully dense, defect-free, ceramic component. A high-solid-loading alumina slurry with suitable rheological and photopolymerisable characteristics for DLP was created. TGA/DSC analysis was used to estimate thermal debinding parameters. The sintering process of the debound parts was studied by employing a numerical model based on thermo-viscoelasticity theory to describe the sintering process. The validated Finite Element Modelling (FEM) code was capable of predicting shrinkage and relative density changes during the sintering cycle, as well as providing meaningful information on the final shape. Archimedes’ principle and scanning electron microscope (SEM) were used to characterise the sintered parts and validate the numerical model. Samples with high relative density (>98.5%) were produced and numerical data showed close matches for predicted shrinkages and relative densities, with less than 2% mismatch between experimental results and simulations. The current model may allow to effectively predict the properties of alumina ceramics produced via DLP and tailor them for specific applications.

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