Low-Cost Carbon-Phenolic Composites for Reentry Body Heatshields

Not Available The overall objectives of this proposal are: a) to demonstrate the feasibility of using rapid, low-cost test methods for screening materials to be used as fasteners in critical assemblies; and b) to rapidly screen existing and new high-strength (120-150ksi) corrosion resistant materials to replace K-Monel, which is unacceptable for critical application at these strength levels due to electrochemical incompatibility with Ti-6Al-4V and Inco 625 and susceptibility to Environmental Assisted Cracking (EAC). The proposed test methods will screen these high-strength materials for significant plasticity and resistance to environmentally assisted cracking (EAC) as outlined in the fracture mechanics approach described in the Fracture Toughness Review Process Document. The materials chosen for this proposal were: Inconel 718, A286, MP35N, and MP159. In addition, three newer materials were selected based upon their potential for good strength and toughness and significantly improved EAC resistance. These three alloys are Carpenter Custom 625 plus, Carpenter PH-465, and Inco 725. In addition Phase I Option testing will be conducted on Monel K-500 fabricated to the same yield strength range for comparison to data previously determined as validation of rapid testing methods and with the results of the testing on the alloy systems for selection for Phase II.