A nickel-base superalloy with refined microstructures and excellent mechanical properties prepared by selective laser melting

• SLM is employed to manufacture the GH4099 alloy for the first time. • Inhibit the precipitation of γ-γ' phase in the as-deposited state. • Excellent tensile properties at room and high temperature are obtained. The brittle γ–γ’ eutectic phase in the inter-dendritic region is the major cause of cracking of GH4099 alloys prepared by laser additive manufacturing technology. In this study, selective laser melting (SLM) was employed to prepare GH4099 alloy with refined microstructures. The alloy showed excellent mechanical properties, while the alloy cracking was retarded effectively. Fine γ′ precipitates were formed after aging treatment, which contributed greatly to the high strength of GH4099 alloy. The tensile strength of the alloy at room temperature and high temperature were 1217.8 and 955.0 MPa, respectively.