Thickness effects of nickel-base single crystal superalloys

The deformation and fracture characteristics of nickel-base single crystal superalloys at high temperatures, which are in plates with different thickness and in different crystallographic orientations, have been studied. The macro-results show that the thickness effects are dependent on the test temperature. The strength increases with decreasing thickness at 1000°C , while the strength increases with increasing thickness below 950°C . At 1000°C, the dependence of strength on crystallographic orientation is not distinct. The micro-results show that [001] plate specimens at 1000°C are in void-related ductile fracture model, and the rest specimens are in micro-face fracture model. And it is confirmed that the microface are crystallographic slip plane, and voids on the faces have important effects on the fracture.