Enhanced CMC Performance Via Sealant Application

High cost and poor environmental performance of CMCs are limiting their deployment in many defense applications. In particular, the JSF platform requires improved durability for a targeted CMC system which is already qualified and in production. Primary motivation for this Phase I effort is to reduce cost. CMCs, although known for their benefits of lightweight and better performance at elevated temperatures, their costs are relatively high compared to metallic counterparts. Cost reduction can be achieved through improved durability or reducing processing steps. Durability is a concern due to high temperature service and harsh environments. Degradation of these CMCs in humid/salt environments is of significant concern to the Navy and this need to be addressed urgently as JSF program advances toward production. In this Phase I project, a sealant application is being proposed to provide protection against pest oxidation at intermediate temperatures during service. The work will be conducted in close collaboration with a defense prime contractor along with other partners for mechanical testing, oxidation modeling, and material suppliers. Critical technical objectives to be addressed in this Phase I project include optimization of the CMC surfaces for better environmental performance and improved reliability along with potentially lowering cost.