Investigating the Feasibility of Preparing Metal–Ceramic Multi-Layered Composites Using Only the Aerosol-Deposition Technique

Abstract

The preparation of metal–ceramic layered composites remains a challenge due to the incompatibilities of the materials at the high temperatures of the co-firing process. For densification, the ceramic thick-film materials must be subjected to high-temperature annealing (usually above 900 °C), which can increase the production costs and limit the use of substrate or co-sintering materials with a low oxidation resistance and a low melting point, such as metals. To overcome these problems, the feasibility of preparing dense, defect-free, metal–ceramic multilayers with a room-temperature-based method should be investigated. In this study, we have shown that the preparation of ceramic–metal Al2O3/Al/Al2O3/Gd multilayers using aerosol deposition (AD) is feasible and represents a simple, reliable and cost-effective approach to substrate functionalisation and protection. Scanning electron microscopy of the multilayers showed that all the layers have a dense, defect-free microstructure and good intra-layer connectivity. The top Al2O3 dielectric layer provides excellent electrical resistance (i.e., 7.7 × 1012 Ω∙m), which is required for reliable electric field applications.

Temperature‐induced changes of the electrical and mechanical properties of aerosol‐deposited BaTiO3 thick films for energy storage applications

“…The latter condition can only be attained by increasing carrier gas pressures that in turn leads to particle interaction with ambient atmosphere, which severely reduces the deposition efficiency. 14,15 Alternatively, AD is a room-temperature, additive manufacturing method that is capable of fabricating scalable ceramic thick films in multilayered structures 16 with high density and nanograined microstructures applicable to a wide variety of substrates, including base metals, glasses, ceramics, and semiconductors. In contrast to cold spraying, the AD process is based on deposition in vacuum conditions, significantly enhancing the applicability of ceramic starting powders.…”

Room temperature deposition of freestanding BaTiO3 films: temperature-induced irreversible structural and chemical relaxation

“…During the deposition process, the kinetic energy of the particles is initially based on the pressure difference between the aerosol generator and the deposition vacuum chamber as well as the nozzle geometry, particle size, and particle morphology. The resulting thick films are nanograined with densities in excess of 97% [2][3][4][5][6][7]. In addition to being a room temperature process, it also requires no process additives, such as binders or plasticizers, common with traditional high-temperature ceramic processing methods.…”

Direct Electrocaloric Characterization of Ceramic Films

“…During the AD process, the powder particles were mixed with a nitrogen carrier gas and formed an aerosol, which was subsequently ejected by a pressure difference and deposited on a substrate (deposition details in Ref. [54]). A 125 µm thick polyimide foil (Kapton ® HN, DuPont, USA) with a pre‐sputtered ≈1 µm thick Au bottom electrode (RF‐magnetron sputtering equipment, 5Pascal, Italy) was used as substrate.…”