Fig. 4: Fatigue crack path profile in the surface-nanolaminated gradient Ti.
From: Nacre-like surface nanolaminates enhance fatigue resistance of pure titanium
a Schematic illustration of the USRP treated sample with a single-edge notch under fatigue loading. b Fatigue crack path in the nanolaminated layer, showing frequent staircase-like crack deflection similar to the cracking behavior observed in nacre as inset (reproduced with permission from ref. 65, CC BY 4.0). Secondary electron (SE) image (c) and the corresponding EBSD-IPF plus IQ map (d), and STEM-BF image of a magnified region of the deflected crack (e), showing the intergranular cracking along the nanolaminates boundary. f EBSD-IPF map of the fatigue crack within the densely twinned layer, with IPF coloring corresponding to that in d. SE image (g) and the corresponding ECC image (h) taken from the region marked in f, showing crack blunting at the twin boundaries. i Schematic illustration of the crack-resisting mechanisms at different stages of fatigue cracking.
