The Ageing Behavior of Titanium Alloy Ti-10V-2Fe-3Al

A good combination of high strength and hardenability makes the alloy Ti 10V-2Fe-3Al a prime candidate for applications in the aerospace arena. However, these properties are very dependent on a post-forming heat treatment. The overall objective of this work is to determine the effect of prior deformation on the aging behaviour. In this particular study, the influence of the heat treatment, either solution and/or aging, on the microstructures, and consequently on the mechanical properties, without introduced strain is reported. Various solution heat treatments have been conducted, either in the beta phase or in the (alpha+beta) phase field, followed by rapid quenching or slow cooling, and aging treatments at different temperatures (250, 350, 400, 500C degrees) above and below the omega-transus temperature. Vickers hardness indentations were used to follow the precipitation hardening behaviour, and mechanical properties were determined using a shear punch test. The aging response is dependent not only on the presence of the athermal omega phase but also on the proximity of the aging temperature to the w-transus. Most treatments showed an unusual initial softening behaviour prior to age hardening, however this appears to be related again to the composition and fraction of the beta phase retained after solution treatment.