Description
This study reports the superplastic deformation behaviour and associated mechanisms in a near-α titanium alloy TA15 (Ti–6Al–2Zr–1Mo–1V). These were investigated at elevated temperatures, ranging from 880°C to 940 °C, and under three strain rates including 0.01 s-1, 0.001 s-1 and 0.0005 s-1. The results exhibits excellent superplastic formability of TA15 alloy over the ranges of temperatures and strain rates investigated. A maximum tensile elongation of 1450 % was achieved at 880 °C and under a medium strain rate of 0.001 s-1. Analysing the stress-strain data shows that at all temperatures, flow stress softening with a minimum percentage of elongation occurs at a relatively fast strain rate of 0.01 s-1 . Strain hardening was observed at all the four investigated temperatures under the medium to slow strain rates (i.e., 0.001 s-1 and 0.0005 s-1). The microstructural evolution was examined using electron backscatter diffraction (EBSD), with the aim of exploring the underlying microstructure based deformation mechanisms. Based on the observed deformation behaviours and microstructure characteristics, a novel physically-based constitutive model is proposed. This model combines a series of parameters, including grain size evolution, dislocation density, void fraction and dynamic recrystallisation (DRX). The material constants for the proposed constitutive equations were determined using a gradient-based optimisation technique. The proposed constitutive model has been validated through a successful implementation in finite element simulation of an industrial component where problems had previously been encountered during superplastic gas-blow forming of TA15 sheet.| Period | 12 May 2023 → 16 May 2023 |
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| Event title | World Titanium Conference 2023 |
| Event type | Conference |
| Location | Edinburgh, United KingdomShow on map |