Search

The graphene nanosheets were dispersed in the superalloy powder by using the wet mixing method, and then the nickel based FGH96 P/M superalloy was prepared with hot isostatic pressing(HIP)+hot extrusion(HEX)+hot isothermal forging(HIF)+heat treating(HT) processes. The results show that the graphene well disperses in the superalloy powder and keeps its original form during the following hot processing. After 0.1%(mass fraction) graphene is added, the average room temperature tensile strength and yield strength increase by 58MPa and 43MPa respectively, and the ductility increases from 21.0% to 37.3%; the tensile strength and yield strength at 650℃ increase by 58MPa and 28MPa, and the ductility increases from 18.5% to 26.5%. The mechanism of strengthening and toughening reinforcement was also analyzed based on graphene reinforced FGH96 superalloy.

Herein, a graphene nanosheet (GNS)/nickel‐based superalloy matrix composite with certain orientated GNS is fabricated via the powder metallurgy method. The solution mixing method is applied to obtain a superalloy powder with embedded GNS. Well‐arranged GNS in the composite can be obtained by subsequent hot isostatic pressing, isothermal extrusion, and isothermal forging, which lead to anisotropic mechanical properties with ductility in radial and tangential direction better than in axial directions. Consequently, a moderate strength improvement (111–116 MPa at 0.1 wt% GNS) is achieved in the composite without losing its ductility in radial and tangential direction, while the elongation reduces from 21.0% to 15.7% in the axial direction. When the loads are perpendicular and parallel to the GNS alignment direction, respectively, two different interface failure modes of "GNS interlayer delamination" and "GNS pulled out" are caused, which result in the anisotropic mechanical behavior. This finding may provide a new perception in informing the strengthening behaviors of GNS‐reinforced FGH96 composite. [ABSTRACT FROM AUTHOR]