Enhanced Thermal, Mechanical, and Physical Properties of CMC's Through Novel Additives

The objective of N22A-T019 STTR PHASE is to enhance and optimize oxidation resistance and thermal, mechanical, and physical properties of ceramic matrix composites (CMCs) through computational-directed and validated design and the addition of additive(s) to the Ceramic matrix.  Advanced  Ceramic Fibers (ACF) and Montana State University (MSU) shall apply validated models, initially formulated in Phase I to be further developed in Phase II to the synthesis of advanced matrices and coatings, using as a baseline monolithic materials (no additives) for comparison to materials with additives in component sub-systems and complete EBC/CMC systems. We shall work in coordination with an appropriate original equipment manufacturer (OEMs) to also establish and execute a test plan that will provide sufficient data for preliminary assessment of design allowables for critical and relevant design requirements. These requirements will be developed in conjunction with an OEM and ONR. Test samples will be manufactured using forming methods such as pressure casting and plasma spray coating to achieve different testing geometries (as necessitated by uniformity and testing hardware requirements).  In these tests lead by ACF and supported by team member MSU ) we shall  determination effects of additives on oxidative performance in selected ceramic matrix materials including a broad range of thermal and mechanical property data, including: density, hardness and impact resistance, thermal conductivity, thermal expansion, tensile strength, modulus, creep, and creep rupture, and vibrational and dynamic fatigue.  Using samples made by ACF  test conditions shall include controlled stress, temperature, and time under environmental conditions, including simulated turbine engine by-products of combustion gases with and without sodium sulfate and water present. For simulated hypersonic conditions we shall test under controlled thermal stress, temperature and environmental conditions including impact tolerance against high speed water and dust. By the end of the Phase II, we shall ensure that the collected data will be available to initiate constituent modeling of modified CMCs with lifetime predictions of oxidation resistance and thermal-mechanical-creep performance up to 100 hours. This data shall also be available to the OEM(s) both following and participating in the program. ACF shall ensure using advanced inductive sample heating methods that thermal-mechanical-creep tests will reach up to 1000 hours at 2000°C or more in air.