Gp. Zhang et al., CRYSTALLOGRAPHIC STUDY OF FATIGUE CRACKING IN NI3AL(CRB) SINGLE-CRYSTAL, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 28(3), 1997, pp. 665-672
The effect of crystallographic orientation on the fatigue-crack initia
tion and propagation in Ni3Al(CrB) single crystal was studied using a
compact-tension specimen. Stage I crystallographic cracking and cleava
ge fracture were observed, Crystallographic cracking can occur on two
or more {111} slip planes simultaneously. It was shown that the thresh
old stress intensity for crack initiation from the notch root exhibits
a dependence on crystallographic orientation, In addition, an effect
of orientation on microcracking behavior was also shown. The number of
{111} planes intersecting with each other determines the different mi
croscopic features on the cleavage fracture surface.