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℃. 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℃. The yield strength reaches its maximum (970 MPa) at 800℃. When the experimental temperature is higher than 800℃, 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℃shows a slide fracture mode. The fractograph from 900 to 1 100℃exhibits a creep rupture mode with uneven deformation.