Surface Slip Deformation Characteristics of Nickel-Base Single Crystal Thin Plates With Film Cooling Holes

In this study, tensile tests at room temperature and observations of slip bands on the free surface of a nickel-based single-crystal thin plate with densely distributed film cooling holes were performed. The deformation of the slip system at the edge of the cooling hole and between the holes was analyzed. Numerical simulation predictions were conducted based on the plasticity theory of crystals, and the comparison with the experimental results showed good consistency. Based on the simulation and experimental results, the nucleation and propagation direction of the edge cracks were analyzed by means of crystallography. The results showed that the fracture surface was mainly attributed to slipping, and the slip traces were approximately in two directions, namely [011] and [01-1], both of which were 45° to the stress axis. The maximum values of the resolved shear stress around the cooling hole were attained at 82.5°, 112.5°, 247.5°, and 277.5°, which corresponded to τ2, τ8, τ10, and τ6.