PSI - Issue 60

M. Suresh Kumar et al. / Procedia Structural Integrity 60 (2024) 433–443 Suresh Kumar et al., / Structural Integrity Procedia 00 (2023) 000 – 000

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Fig. 8. SEM fractographs of the fatigue tested samples of (a) AR; (b) 200 HT; (c) 300 HT

Delamination fractures were reported in Al – Li alloys exhibiting poor short-transverse (ST) strength properties due to elongated and un-recrystallized pan cake-type grains (Venkateswara Rao et al. (1989)). These fractures are also caused by planar slip, grain boundary precipitates, grain boundary segregation, and highly misoriented grain boundaries >30 o neighbouring grains with higher Taylor factor differences (Tayon et al. (2009)).

Fig 9. (a) Striations in the fatigue crack propagation region; (b) Delaminations at the crack initiation region