Use of Titanium alloys for shock oriented marine applications
Résumé
Use of Titanium alloys as base materials for sea water circuits of DCNS submarines is growing. Substitution of Nickel alloys or super-stainless steels by Titanium alloys is however limited by the lower behavior of the latter under military shock loading. Due to the low ductility of Titanium alloys, notch sensitivity-related risks and brittle fracture conditions needed further investigations. The present work deals with the mechanical behavior under dynamic loading (tension, fracture toughness) of cast Titanium: CP grade 2 and Ti-6Al-4V grade 5. Models and a full-scale demonstrator were then tested on shock equipment up to 450G accelerations, with notches previously machined on parts in order to verify potential failures. Results are very convincing and show the opportunity of Titanium solution even if shocks are present.