Fabrication and Characterization of Dense Ceramic Coatings by Aerosol Deposition

Advanced ceramic coatings are attractive in many industries, ranging from microelectronics to aerospace. Fabricating dense ceramic coatings using established techniques is challenging due to the brittleness and high melting temperature of ceramics. Aerosol deposition (AD) is a solid-state coating process capable of producing dense nanocrystalline ceramic films. AD has attracted attention in the ceramic coating field due to its unique features, including the room temperature nature, high film density with crack-free structure, controllable coating thickness, relatively high deposition rate, good mechanical properties, and a wide choice of substrates. However, as a novel technique, the deposition mechanism has not been fully understood yet. This study aims to analyze the adhesion mechanism of AD, focusing on the effect of powder size and substrate properties on the first layer formation, also called the anchoring layer. A deposition system has been designed and assembled. Raw alumina (Al₂O₃) powders were pre-treated to obtain different particle sizes and size distributions. To illustrate the effect of substrate roughness and hardness, stainless steel, alumina, and glass plates were used.