The effect of heat treatment temperature on the mechanical properties of TIMETAL® 575

TIMETAL (R) 575 is an alpha + ss alloy reported to possess superior dwell fatigue capabilities over the conventionally used Ti-6Al-4V. The increased performance of this alloy has in part been linked to the presence of fine-scale tertiary alpha precipitates, which are present in the microstructure following suitable post-forging heat treatments. However, there is currently little understanding as to the extent that these precipitates influence the mechanical properties. When this is coupled with limited information regarding the temperatures over which tertiary alpha is expected to form, and other microstructural changes which may be occurring concurrent to the evolution of tertiary alpha in the microstructure, an incomplete picture arises to the true nature of tertiary alpha on mechanical behaviour. Therefore, this study aims to characterise the mechanical properties of TIMETAL (R) 575 across a number of different heat treatment temperatures to assess the sensitivity of the mechanical properties on the microstructure.