PROTECTIVE COATINGS FOR CERAMIC MATRIX COMPOSITE SUBSTRATES AND METHODS FOR IMPROVING THE WEAR RESISTANCE THEREOF AND COATED ARTICLES PRODUCED THEREFROM

摘要

Coated articles adapted to be subjected to direct and sustained mechanical contact are provided. The coated articles include a ceramic matrix composite (CMC) substrate. A solid coating is disposed directly on and adheres to the substrate during such direct and sustained mechanical contact. The solid coating is formed from a precursor comprising a liquid binder, which may be sodium silicate, a basic colloidal alumina solution, aluminum hydroxide, aluminum oxychloride, aluminum hydroxylchloride, aluminum phosphate, and phosphoric acid. The coating may also include a filler material such as solid powder, chopped fibers, and combinations thereof.;Methods for improving the wear resistance of an article made from the CMC substrates are also provided. A CMC substrate is provided and covered with a slurry. The slurry includes the liquid binder and optionally, the filler material. The slurry is consolidated, for example, by annealing to form a wear-resistant solid coating on the article.