Tensile and fracture toughness of high strength β Titanium alloy, Ti–10V–2Fe–3Al, as a function of rolling and solution treatment temperatures

The effect of processing and heat treatment has been studied on tensile properties and fracture toughness of a high strength metastable beta titanium alloy, Ti–10V–2Fe–3Al. The alloy was double melted by vacuum arc melting and subsequently subjected to thermomechanical processing that included combinations of rolling and solution heat treatment both in α−β and β phase fields. Rolling temperatures were varied from 710 °C (sub-transus) to 860 °C (super-transus) and solution treatment temperatures were varied from 710 °C (sub-transus) to 830 °C (super-transus). A systematic microstructural investigation (optical as well as scanning electron microscopy) was undertaken in order to correlate the property trends with underlying microstructure which is strongly dependent on the thermomechanical processing sequence. A subtransus rolling followed by subtransus solution treatment resulted in equiaxed α morphology whereas a supertransus rolling followed by subtransus solution treatment resulted in more acicular/lenticular morphology of α phase. While α−β rolling followed by α−β heat treatment gave better tensile properties, β rolling followed by α−β heat treatment resulted in superior fracture toughness.