Figure 3.

Effect of herringbone grafted interfaces on fracture mechanics. (a) Self-healed samples with flat and herringbone (17.5° and 35°) interfaces grafted using separately cast halves. (b) Uniaxial tension (500 mm/min ≈ 0.1/s) stress–strain curves and toughness data comparing flat and herringbone grafted interface performance on cast samples with imperfect self-healing conditions. The 17.5° interfaces increased toughness by a factor of 18, compared to flat interfaces. (c) 35° grafted tensile specimen fracture primarily due to adhesive failure. (d) 17.5° grafted tensile specimens failed cohesively straight across the healed interface. (e) DIC engineering strain measurements of a 17.5° sample revealing strain localization near the healed interface. In this sample, the strain localization at the tip of the left tooth is consistent with cohesive fracture in the material away from the healed interface.