Abstract
Sprayed preforms were fabricated with Ti-4.5Al-3V-2Mo-2Fe alloy (SP-700) powder of 23∼53 μm diameter instead of conventional powder of 23∼150 μm diameter to make the microstructure of the sprayed deposit fine. SCS-6/SP-700 composite made of the improved sprayed preforms (improved spray composite) showed superplasticity in the tensile direction perpendicular to the fiber with a maximum m-value of 0.58 at 1048 K. The tensile flow stress of the improved spray composite was a little lower than that of SCS-6/SP-700 composite made of woven preforms. Tensile strength at room temperature of the improved spray composite after deformation was comparable to that of the improved spray composite before deformation. Stringer- and blade-shaped TMC part models are demonstrated to be successfully superplastic-formed. No debonding defects at fiber/matrix interface were observed in the blade-shaped model using the improved spray composite.
