Structural Fasteners for Extreme Temperature Utilization 670887
Fasteners, specifically threaded types, can be fabricated from columbium, molybdenum, and tantalum alloys employing conventional equipment and special handling procedures. Limited success in development of blind fasteners has been realized with columbium and tantalum alloys; however, embrittlement of the substrate by the required protective coating makes deformation difficult and lack of coating ductility prevents assured oxidation protection where post installation coating is not possible. Dispersion strengthened metals (DSM) which offer excellent thermal stability may also be fabricated into useful fastener configurations. Summary of strength and oxidation test results of fasteners are presented and future materials for fastener developments are discussed.