This Phase 1 proposal will demonstrate the performance and processing advantages of a Ultra High Temperature (UHT)graded carbide-boride matrix CMC densified by TA&Tâs rapid gas pulsed, reverse thermal gradient (GP-RTG) CVI process. A systematic approach for developing and optimizing the CVI Protocols for infiltration of a 3D woven carbon fiber preform includes incremental examination of the matrix densification and composition profile as a function of infiltration time. Feedback from these analyses will be used to adjust infiltration conditions. High temperature thermal and mechanical properties will be measured and correlated with the experimental UHT CMC microstructural and compositional characteristics. A preliminary processing cost analysis will be conducted for comparison to isothermal CVI and other CMC densification methods and will included in a Final Report with all the experimental results, analyses and conclusions. Approved for Public Release | 20-MDA-10643 (3 Dec 20