TY - JOUR
T1 - Effect of grain morphology on the mechanical properties of GH4099 superalloy fabricated by laser powder bed fusion
AU - Qian, Yuanhong
AU - Gu, Liangxian
AU - Chen, Rong
AU - Yang, Haiou
AU - Li, Zhiyong
AU - Cui, Zhaowen
N1 - Publisher Copyright:
© 2026
PY - 2026/2
Y1 - 2026/2
N2 - This work systematically investigates the evolution of grain morphology and its effect on the mechanical properties of GH4099 nickel-based superalloy fabricated by laser powder bed fusion (L-PBF) under different heat treatment conditions. By comparing the as-built columnar grains (H1), fully recrystallized equiaxed grains (H2), and their respective precipitation-strengthened states (HA1, HA2), it is revealed that high-temperature homogenization (1160 °C) effectively triggers static recrystallization, significantly improving grain sphericity and structural uniformity, thereby enhancing ductility. Aging treatments promote the precipitation of γ′ phases in large volume fractions, markedly increasing yield strength (HA1: 955 MPa, HA2: 761 MPa), albeit with some reduction in ductility. Cyclic loading–unloading tests demonstrate that highly uniform equiaxed grains with complex grain boundary networks (HA2) substantially improve back-stress uniformity, toughness, and energy dissipation capacity. Through comprehensive microstructural characterization and mechanical analysis, the microstructural control paths for optimizing the strength–ductility balance and service reliability of SLM GH4099 are elucidated, providing theoretical support for process optimization and engineering application of additively manufactured superalloys.
AB - This work systematically investigates the evolution of grain morphology and its effect on the mechanical properties of GH4099 nickel-based superalloy fabricated by laser powder bed fusion (L-PBF) under different heat treatment conditions. By comparing the as-built columnar grains (H1), fully recrystallized equiaxed grains (H2), and their respective precipitation-strengthened states (HA1, HA2), it is revealed that high-temperature homogenization (1160 °C) effectively triggers static recrystallization, significantly improving grain sphericity and structural uniformity, thereby enhancing ductility. Aging treatments promote the precipitation of γ′ phases in large volume fractions, markedly increasing yield strength (HA1: 955 MPa, HA2: 761 MPa), albeit with some reduction in ductility. Cyclic loading–unloading tests demonstrate that highly uniform equiaxed grains with complex grain boundary networks (HA2) substantially improve back-stress uniformity, toughness, and energy dissipation capacity. Through comprehensive microstructural characterization and mechanical analysis, the microstructural control paths for optimizing the strength–ductility balance and service reliability of SLM GH4099 are elucidated, providing theoretical support for process optimization and engineering application of additively manufactured superalloys.
KW - Cyclic loading–unloading
KW - GH4099 superalloy
KW - Grain morphology
KW - Heat treatment
KW - Laser powder bed fusion
KW - Mechanical properties
UR - https://www.scopus.com/pages/publications/105027161633
U2 - 10.1016/j.msea.2026.149739
DO - 10.1016/j.msea.2026.149739
M3 - 文章
AN - SCOPUS:105027161633
SN - 0921-5093
VL - 953
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
M1 - 149739
ER -