Tensile behavior of nickel-base single-crystal superalloy DD6

Tensile behavior of the nickel-base single-crystal superalloy DD6 was studied from room temperature to 1020. °C. The plate specimens were along [001] orientation parallel to the loading axis in tension. The microstructures on the surface and fracture morphology were investigated after tensile test to rupture by scanning electron microscopy (SEM). The results of the present investigation indicate that the yield strength at 650. °C is superior to that at room temperature, 850. °C and 1020. °C. Low ductility and serrated flow in stress-strain curves were also observed at 650. °C. The microstructures on the surface of the plate specimens and fracture morphology observation indicated that localized slip which resulted in glide plane decohesion caused the low ductility of DD6 alloy.