PSI - Issue 60

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Mantosh Mandal et al. / Procedia Structural Integrity 60 (2024) 510–516 Mantosh Mandal/ StructuralIntegrity Procedia 00 (2019) 000 – 000

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(a)

(b)

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(d)

Figure 2 : Simulated defects on the curved surface of cylinders compressed at 1175 o C using strain rates of (a) 20s -1 , (b) 5s -1 ; (c) macrograph of midsection corresponding to (a); (d) micrograph corresponding to (c) showing cracks at grain boundaries.

While some cracks were found to initiate from the curved surface (Fig. 2 (d)), others were found to initiate at grain boundary-triple junctions. An example of such initiation is shown in Fig. 3 (a), where crack initiation at a triple junction is encircled. The adjacent grains exhibit prominent slip bands, the directions of which are indicated by the arrows in Fig. 3 (a). The slip bands denote dislocation glide along different slip systems [9]. The slip bands generally terminate at the grain boundaries, indicating resistance to slip from the grain boundaries. The level of resistance depends on various factors, including dislocation – dislocation interactions in the case of pileup and the overall effectiveness of the grain boundary in resisting slip [10]. Dislocation – dislocation interactions can lead to