Dr. Emma Calver worked on the FAST-forging of Ti-5553. Her PhD was sponsored by SAFRAN Landing Systems (formerly Messier-Bugatti-Dowty), who make landing gear systems for commercial aircraft. Although making landing gear from titanium alloys is highly beneficial, as they have higher strength-to-weight ratio and reduced corrosion maintenance when compared to stainless steels, the high cost of titanium alloy production means it is uneconomical to replace stainless steel parts with titanium ones.
A cheaper titanium processing route is therefore being investigated, in order to determine if titanium alloy parts can viably replace stainless steel parts. This processing route involves: producing titanium alloy powder directly from titanium ore via the Metalysis (FFC) electrolysis process; consolidating the powder to pre-forged billet via the FAST (field-assisted sintering technology) process; forging the billet in one or two steps; heat treating to produce optimal microstructure; and machining to final shape, as with conventional processing.
The main aim of her project was to tailor the final microstructure of Ti-5553 during the FAST process, forging process, and subsequent heat treatment. This demonstrated the suitability of the FAST-forge process for a conventional beta titanium alloy, and allowed a direct comparison with material produced by the conventional processing route.