Supersonically sprayed clay, silica, and silica aerogel hybrid films as thermal and electrical barriers

A thermal barrier coating (TBC) provides protection from thermal damage. While sufficiently thick coatings facilitate thermal protection, space limitations often require the use of high-performing barrier materials, such as clays, silica, and aerogels. Herein, we demonstrate the fabrication of thin TBCs of clay, silica, and silica aerogel microparticles deposited by supersonic cold spraying. The coated films were characterized by scanning electron microscopy and transmission electron microscopy. The effects of varied coating thicknesses from 1 to 5 mm on the TBC performance of each material were studied for both heating and cooling scenarios. We found that the hybrid clay–aerogel coating provided the best thermal insulation. Deposition by supersonic cold spraying is rapid and scalable, with potential applicability for the commercial production of TBCs.