Tensile and fracture behavior of DZ951 Ni-base superalloy

The tensile and fracture behavior of DZ951 directionally solidified Ni-base superalloy was studied in the temperature range of 20-1 100 degrees C. The fracture mode was examined by scanning electron microscopy. The results show the experimental temperature has no significant effect on the tensile strengths, which are greater than 1 000 MPa from room temperature to 800 degrees C. The yield strength reaches its maximum (970 MPa) at 800 degrees C. When the experimental temperature is higher than 800 degrees C, the tensile and yield strengths decrease evidently and the ductility increases remarkably. The fractograph of fracture surface for the tensile specimen at room temperature shows a dimple-ductile fracture mode. The fractograph from 600 to 800 degrees C shows a slide fracture mode. The fractograph from 900 to 1 100 degrees C exhibits a creep rupture mode with uneven deformation.