Oxidation resistant fibre coatings on the basis of lanthanum phosphate for CMCs

This internship report of second year study in engineering school deals with Ceramic Matrix Composite manufactured by polymer infiltration and pyrolysis process (PIP). In order to improve the behavior of CMCs in oxidizing atmosphere a new coating based lanthanum phosphate is investigated and described in detail. Firstly parameters of the coating process are analyzed like the influence of the sizing, the duration of the firing and the temperature of the firing. In the second part more temperatures are investigated as some parameters are fixed thanks to the first study. In the third part the influence of a second coating is tested. In the fourth part the coated fibers are put in conditions of a plate production. All these investigations were made thanks to scanning electron microscopy (SEM), mass measurements and calculation of the coating thickness. Due to conclusions, a new protocol for lanthanum phosphate coating was made and will be used in order to produce CMCs