Influence of the crystalline orientations on microcrack initiation in low-cycle fatigue

Macrozones and dwell fatigue crack initiation in Ti‐6Al‐4V

“…The facet plane, often reported to be at-or near-basal, of course does not itself have a high Schmid factor for basal slip. This is in agreement with observations by P.Mu et al that crack initiation in steels is not necessarily on planes with the highest Schmid factor [15].…”

Fatigue crack initiation and crystallographic growth in 316L stainless steel

“…However, once it becomes longer than several grain sizes it grows perpendicular to the loading axis and favours mode I of crack opening. The fact that mode I is the most damaging mode [20] is consistent with these simulation results.…”

Influence of local crystallographic configuration on microcrack initiation in fatigued 316LN stainless steel: Experiments and crystal plasticity finite elements simulations

“…Surface relief topography and its role in the formation of transgranular 3 micro-crack have been widely studied in face-centered-cubic (fcc) single crystals (mainly pure copper and aluminium) and, to a lesser extent, in polycrystalline alloys. Intergranular cracks are also observed at surface of polycrystalline metals [5][6][7][8][9] and may be explained in some cases by impingement of PSBs at grain boundary [6,[10][11] although the studies of the basic mechanisms leading to fatigue crack initiation at grain or twin boundary are less numerous.…”

“…Conversely, SEM observations of a large number of transgranular cracks initiated along PSMs, combined with electron backscatter diffraction (EBSD) measurements, are intended to provide more statistical information about initiation sites without accurate knowledge of PSMs shape [9,17]. It has been found that cracks initiate mainly within grains which exhibit a rather high Schmid factor.…”

“…From the well-documented low cycle fatigue behaviour of several 316, 316L or 316LN type steels (e.g. [7,9,12,39]), micro-cracks initiated along PSMs are known to be predominant, although grain boundary and twin boundary cracks can also be observed. The influence of temperature and environment is not addressed here.…”