Effect of hot compressive deformation on the martensite transformation of Ti–10V–2Fe–3Al titanium alloy

Formation of Deformation-Induced Products in a Metastable-β Titanium Alloy during High Temperature Compression

“…A typical true stress-true strain curve shows continuous flow softening after rapid increase up to a maximum stress of ~150 ± 0.4 MPa at 0.07 strain, which is usual response for β titanium alloys deformed at a temperature slightly below β transus (nearly 100 °C) [6,11,29,30]. Although flow softening has been reported for Ti-10-2-3 alloy deformed above the β transus temperature [11,13], the tendency of β titanium alloys deformed below the transus temperature towards flow softening is stronger [11,30]. Microstructure observation was performed at the centre of the sample cross-section ((Normal Direction (ND)) × (Compression Direction (CD) plane)) using a JEOL-JSM 7001F Field Emission Gun-Scanning Electron Microscope (FEG-SEM) (JEOL, Tokyo, Japan)operating at 15 kV voltage and 10 mm working distance.…”

“…During the former, the dislocations formed during deformation are easily annihilated and readily rearranged as arrays, leading to the formation of subgrains with low angle boundaries, whereas new strain-free grains are formed during DRX [24]. It has been reported that since at low strain rate, such as 10 −3 s −1 , the time required for DRV and DRX is adequate, the softening mechanism is predominant [11].…”

“…The contribution of the dislocation stored energy to the chemical potential gave rise to the transformation of β matrix to the athermal α". Lei et al [11] similarly concluded that the higher the mechanical instability of β phase that resulted from the deformation above β transus temperature, the more athermal α" martensite forms. However, limited studies have been conducted on hot deformation of metastable titanium alloys below the β transus temperature.…”

“…%) (hereafter designed as Ti-10-2-3) utilised in landing gear of Boeing 777, are generally easily affected by small variation in both temperature and strain rate [7]. Therefore, studies have been focused on the hot deformation mechanisms and microstructural evolution under different deformation conditions in order to optimise processing parameters and mechanical properties of metastable-β titanium alloys [8][9][10][11][12].…”

Formation of Deformation-Induced Products in a Metastable β-titanium Alloy during High Temperature Compression

“…The contribution of 47 the dislocation stored energy to the chemical potential gave rise to the transformation of β matrix to 48 the athermal α". Lei et al [11] similarly concluded that the higher the mechanical instability of β phase 49 that resulted from the deformation above β transus temperature, the more athermal α" martensite 50 forms. However, limited studies have been conducted on hot deformation of metastable titanium 51 alloys below the β transus temperature.…”