• A novel Ni-based superalloy with 0.1 wt.% graphene nanosheets (GNs) exhibits a 31 HV increase in hardness and 86 MPa increase in yield strength compared to the base alloy, due to synergistic strengthening from in-situ formed nano-carbides and residual GNs.
• The in-situ reaction of GNs with alloy melt during laser powder bed fusion generates uniformly dispersed nano-carbides that refine the cellular structure and hinder dislocation movement, enhancing mechanical properties.
• The study demonstrates the potential of using graphene as a strengthening agent in additive manufacturing, offering a promising alternative to conventional refractory element addition for high-performance superalloys.
• The combination of SEM, EBSD, TEM, DSC, and SANS provides comprehensive microstructural and thermophysical characterization, confirming the presence and distribution of nano-carbides and residual GNs.