NSF Award
0512257
The research aims to tailor the electrostatic self-assembly technique towards buildup of hybrid, functionally graded ceramic nanocomposites with unique combinations of heat resistance, thermal insulation and oxygen barrier qualities, hot-corrosion and erosion resistance, fatigue life, resistance to adverse coating/substrate interaction, thermal expansion mismatch effects, adhesion capacity, and high-temperature mechanical performance. Electrostatic self-assembly offers powerful and practical means of processing diverse nanosize ceramic (and other) constituents (nanotubes, nanofibers, nanoplatelets and nanoparticles) into highly compact nanolayers which, upon sintering, yield dense nanolayered composites of near-perfect structure, that are functionally graded to meet the multi-faceted demands on various aspects of thermal barrier coating performance The self-assembled coatings with functionally graded nanostructures will be tested in order to validate the merits of electrostatic self-assembly as a practical approach for controlled and thorough integration of nanosize constituents into near-perfect, functionally graded nanocomposites. The experimental effort will also verify that self-assembled nanolayered composites complement the tremendous performance attributes associated with the near-perfect structure of nanosize constituents with the gains in thermomechanical and barrier qualities brought about by nano-spaced interfaces in nanolayered composites.<br/><br/>Commercially, electrostatic self-assembly offers major economic, environmental and energy advantages over alternative coating techniques. The new class of nanostructured, functionally graded coatings can also be tailored to meet broader requirements in the fields of corrosion protection and wear resistance. Thermal barrier coatings with substantially enhanced performance attributes are critically needed to meet the increasingly stringent requirements in gas turbines, solid rocket nozzles, reentry vehicles, and many other applications. The emerging designs in these applications generally involve further temperature rise for enhanced performance and efficiency; breakthrough technological developments are needed to meet the demands on thermal protection systems in the increasingly severe service environments of future systems.
