Microstructure and mechanical properties of recycled Ni₃Al base alloy IC6

The effect of recycle proportion on the composition, microstructure and mechanical properties of recycled Ni₃Al base alloy IC6 was examined by scanning electron microscopy with X-ray energy-dispersive spectrometer (SEM/EDS) and transmission electron microscopy (TEM). The results indicate that the addition of recycled scraps has no obvious effect on the chemical composition, except the content of C and N increases with the addition proportion of recycled scraps. The microstructure of IC6 recycled alloys has no obvious difference compared with the fresh alloy, except some M₆C carbides precipitate in the interdendritic area. In contrast with fresh alloy, tensile properties at R. T. of the IC6 recycled alloys have almost no change, the high temperature stress rupture properties decrease slightly, and the thermal fatigue properties deteriorate obviously. The recycle proportion of IC6 alloy should not exceed 50% in production of gas turbine vanes.