Advances and challenges in direct additive manufacturing of Al2O3 and ZrO2-based Eutectic Ceramic Oxide

Al₂O₃-based directionally solidified eutectic ceramics have garnered significant interest over the past decades due to their exceptional high-temperature strength retention and creep resistance compared to metal alloys, as well as their superior oxidation resistance and microstructural stability relative to other ceramics. For these reasons, they have been identified as some of the most promising candidates for ultra-high-temperature structural applications. From a processing perspective, oxide eutectic composite ceramics have been produced through various solidification methods. However, these methods are often unable to achieve fine microstructures or fabricate large or complex-shaped components. To address these limitations, additive manufacturing (AM) presents a promising alternative for the production of monolithic and complex-shaped ceramic parts with fine and homogeneous microstructures. The aim of this study is to evaluate the feasibility of using L-PBF technologies for the production of Al₂O₃-based eutectic ceramics. In the initial phase of the study, the focus was on characterizing and optimizing the particle size distribution (PSD) of eutectic Al₂O₃-ZrO₂ based granules for use in various laser powder bed fusion (PBF) technologies. Initial characterization, performed using SEM imaging and laser granulometry, assessed the PSD, average particle size, and distribution width of the engineered batches. Subsequently, the optimized ceramic powders, with tailored size distributions, morphologies, and compositions, were selected for specific applications in L-PBF (fiber laser) and L-PBF (CO₂ laser) technologies. The addition of graphene to the studied compositions enabled an evaluation of its impact on laser beam absorption.