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Advisor(s)
Abstract(s)
In the areas of aeronautics and aerospace, ceramic composites play an essential and increasing
role due to their superior performance and tailorable properties, exhibiting highly specialized
mechanical, thermal, and electric features1. Their main applications include thermal protection
systems (TPS), thermal barrier coatings (TBC), and dielectric barrier discharge (DBD) plasma
actuators, both for instrumentation and control purposes2. This work reports the manufacture and
characterization of three ceramic composites capable of fulfilling the multifunctional ceramic
condition according to the aforementioned applications. Accordingly, MgO-Al2O3 (MA), MgOCaZrO3
(MCZ), and Y2O3 stabilized ZrO2 (YSZ) are introduced for TPS, TBC, and DBD dielectric
elements. To this aim, MA, MCZ, and YSZ ceramic composites were fabricated via a sequential
process, encompassing the selection of raw powders and milling, die pressing, and sintering. Further,
the samples were polished for surface optimization.
Overall, the results obtained, including mechanical (Young’s and shear moduli, flexural strength,
hardness, and fracture toughness), thermal (thermal conductivity and thermal expansion (CTE)), and
electrical (dielectric constant) properties, report evidence that the developed ceramics show suitable
multifunctional characteristics and therefore fulfil the aeronautical and aerospace demands for
increased materials performances. The combined analysis of the Young’s and shear moduli (Fig.1a)
with the CTE – the latter over a wide range of temperatures (Fig. 1b) – allows concluding that the
cost-effective and widely used alumina appears suitable for bulk monolithic (TPS) and joint
applications (TPS, TBC, and DBD).
Description
Keywords
Ceramic composites Multifunctional advanced ceramics Thermal protection systems Thermal barrier coatings Dielectric barrier discharge