Fig. 1 Schematic diagram showing the relationship among applied stress (τapp), interaction stress (△τ) and actual stress of α and β phases [51]

Fig. 2 In situ TEM observation of the dislocation emission from a αp/β interface [54]

Fig. 3 Slip traces in TA19 titanium alloy during deformation: a slip traces appear preferentially in equiaxed α phase [32], b slip traces just present in interlayer β phase [48]

Fig. 4 SF distribution of basal and prismatic slip systems of Ti-5Al-2.5Sn alloy during early deformation [78]

Fig. 5 Effect of α grain size and morphology on the deformation mechanism in TC21 titanium alloy [45]: a the localized deformation within equiaxed α and α lath, b comparison of the frequency of slip traces within equiaxed α and α lath

Fig. 6 Slip trace analysis of the deformed micropillars with β-vertical (left) and β-inclined (right) structure [86]

Fig. 7 Geometry of slip transfer across a grain boundary [87]

Fig. 8 Schematic illustration of the direct slip transfer process [95]

Fig. 9 AFM image of slip band and slip step in Ti-6Al-4V alloy during α/β slip transfer when the α and β phases satisfy the BOR [107]

Fig. 10 Slip transfer behavior of α and β phases with BOR in TC21 titanium alloy [108]: a basal slip transmission across the α/β interface, b prismatic slip transmission with an inclined angle of 10° is observed from α to β phase

Fig. 11 Continuous slip traces in TA15 titanium alloy [109]

Fig. 12 SEM observation of crack initiation in Ti-6Al alloy [46]: a initial, b 0.2 mm, c 0.3 mm, d 0.4 mm and e KAM map after loading to the displacement of 0.4 mm

Fig. 13 The Stroh model for planar slip [116,117]

Fig. 14 Crack initiation behavior in Ti-6Al-4V alloy [124]