Investigating the anisotropic behavior and high-temperature mechanical properties of GH4251 nickel-based superalloy prepared by selective laser melting and post heat treatment

GH4251 nickel-based superalloy prepared by selective laser melting (SLM) exhibits pronounced anisotropy. In this study, the anisotropic behavior and high temperature mechanical properties of SLMed GH4251 superalloy with different solution heat treatment temperatures (1070 °C, 1120 °C, 1130 °C and 1170 °C) at 700 °C were systematically investigated. The results reveal that there is a temperature inflection point among 1120 °C-1130 °C, below which GH4251 superalloy shows an obvious {001} texture orientation in the deposition direction, making the alloy exhibit a significantly higher elongation under a comparable tensile strength. Above the inflection point, a large number of secondary γ' phases are precipitated out and the dynamic recrystallization of the superalloy occurs, which significantly reduces the mechanical anisotropy. Additionally, the study delves into the detailed discussion of the strengthening mechanisms of the SLMed GH4251 superalloy. •Solid solution combined with double aging treatment can alleviate the anisotropy of mechanical properties of SLMed GH4251.•The crystal structure and anisotropy of the alloy changed considerably when the temperature was between 1120°C and 1130°C.•The high temperature alloy SA-1170 has isotropic tensile properties.•The deformation mechanisms of SLMed GH4251 after heat treatment was studied in detail.