Anisotropy of small punch creep performance of selective laser melted GH4169 at 650 °C

The large temperature gradient and the epitaxial growth of grains during selective laser melting process usually lead to the mechanical anisotropy of metal parts. To evaluate creep anisotropy of selective laser melting-fabricated GH4169 alloy, in this paper creep performance of GH4169 was investigated by means of small punch creep test method. The effect of the small punch loading-induced prestrain on creep properties of the specimens was examined. The results indicate that under the same heat-treatment and the loading conditions, the small punch creep specimens loaded along the building direction have the longer creep life and the larger creep plasticity than the ones loaded along the scanning direction. The finding reveals that loading deformation-induced dynamic recrystallization has a significant effect on improving creep properties by weakening anisotropy properly. The small punch creep properties of the specimens loaded along the building direction superior to that of the specimens loaded along the scanning direction are mainly attributed to the higher deformability of heterogeneous microstructure, the lower recrystallization activation energy and the deformation activation energy.