High temperature moisture sealants for hot exhaust structures on advanced system

This Phase II project will extend the investigation of Phase I effort to further enhance and mature a sealant technology to limit or prevent environmental degradation of aircraft exhaust coatings that provide thermal and corrosion protection to the underlying substrate. The environmental degradation problem is a severe and urgent problem faced by DoD across many advanced aircraft platforms resulting in enormous maintenance costs and impacting war fighter readiness.The problem is further exasperated with thermal cycling anticipated in service and hence the solution must be thermally stable and robust to withstand engine operations in aggressive environments.In addition, the sealant must not adversely impact mechanical properties of the hardware or should not result in measurable added weight.The Phase II technical objectives include further optimization of the sealant material and process, demonstration of sealant application on specimens at the engine OEM facility, comprehensive testing and validation of sealant performance to be conducted by the engine OEM, and initial feasibility study for scaling up the sealant application process on hardware-relevant large-scale geometries.A manufacturing friendly process will be pursued in the Phase II project for ease of adoption and possible insertion into the fleet.