Research Progress on Anisotropic Mechanical Properties of Laser Additive Manufactured GH4169 Nickel-based Superalloy and Its Heat Treatment Regulation

GH4169 nickel-based superalloy, renowned for its low crack susceptibility and excellent high-temperature mechanical properties, stands as an ideal material for laser additive manufactured（LAM） aerospace high-temperature components. However, LAM GH4169 currently faces critical challenges, including significant anisotropy, unclear high-temperature influence mechanisms and insufficient fatigue performance research, which severely hinders its industrial adoption. Heat treatment, a cost-effective and efficient post-processing technique, can effectively regulate the microstructure and mechanical properties of metallic materials. However, the underlying regulation mechanisms of heat treatment on LAM GH4169 remain highly complex, demanding further in-depth investigation. The anisotropic mechanical properties of LAM GH4169 superalloy were comprehensively reviewed, its unique microstructure, anisotropic tensile and fatigue properties were analyzed, the effects of heat treatment on the microstructure and mechanical performance were summarized, and the key unresolved issues and challenges were identified. Finally, the future research directions were proposed to advance the application of laser additive manufactured nickel-based superalloys in high-temperature aerospace structures.