Mechanical Properties and Strain Hardening Behavior of Few‐Layered Graphene Nanosheets‐Reinforced Powder Metallurgy Nickel‐Based Superalloy Metal Matrix Composites

Abstract

Herein, few‐layered graphene nanosheets (GNS) with approximately 3, 6, or 9 layers are used to reinforce high‐performance nickel‐based superalloy metal matrix composite. A powder metallurgy method comprising solution‐mixing, hot isostatic pressing, and thermal processing is used to prepare GNS‐FGH96 composites with different numbers of GNS layers as well as referential FGH96 matrix materials. Compared with those of unreinforced FGH96, the mechanical properties of the GNS‐FGH96 composites are enhanced, specifically, the ≈6 layers GNS‐FGH96 composite exhibits an ultimate tensile strength of 1660 MPa and a yield strength of 1229 MPa, which are 9.79% and 6.87% higher, respectively, than those without the addition of GNS. Furthermore, the ≈6 layers GNS‐FGH96 composite exhibits the highest elongation‐at‐fracture of 29.9%. The as‐prepared GNS‐FGH96 composites show a good balance of strength and ductility owing to the increased dislocation density between the FGH96 matrix and GNS reinforcement interface area, as well as the high structural integrity of the GNS. Thus, this study provides a novel approach for designing and creating high‐performance graphene‐reinforced FGH96 metal matrix composites that exhibit exceptional strength and toughness.