Effect of Heat Treatment on Microstructure and Properties of FGH4096M Superalloy Processed by Selective Laser Melting
Effect of Heat Treatment on Microstructure and Properties of FGH4096M Superalloy Processed by Selective Laser Melting
Zhibo Hao(University of Science and Technology Beijing (USTB)); Tian Tian(University of Science and Technology Beijing (USTB)); Shiqing Peng(University of Science and Technology Beijing (USTB)); Changchun Ge(University of Science and Technology Beijing (USTB)); Xinggang Li(Southern University of Science and Technology (SUSTech)); Chonglin Jia(Beijing Institute of Aeronautical Materials (BIAM)); Chuan Guo(Southern University of Science and Technology (SUSTech)); Qiang Zhu(Southern University of Science and Technology (SUSTech))
26권 8호, 1270~1285쪽
초록
A self-designed nickel-based superalloy, designated as FGH4096M, was prepared by selective laser melting (SLM). Differentheat treatments were performed to improve the mechanical properties of the SLM alloy through optimizing the microstructuresand the features of γ′ precipitates. Compared with the as-deposited alloy, the columnar grains with dendritic structuresand equiaxed structures were retained in the alloy after direct aging, but a large amount of tertiary γ′ phase precipitated,especially around the sub-grain boundaries, resulting in the highest tensile strength but the lowest elongation. During solidsolution and aging treatment (SSA), the recovery and recrystallization occurring in the alloy facilitated the grains to beequiaxed with the increase of solution temperature. For lower solution temperature (below 1100 ℃), the secondary γ′ precipitatesdecreased with the increase of solution temperature, while the tertiary γ′ precipitates from the subsequent agingprocess gradually increased; for higher solution temperature over 1100 ℃, exceeding the complete dissolution temperatureof the γ′ phase, only tertiary γ′ precipitates from the subsequent aging process were uniformly distributed in the alloy. Afterdouble solid solution (1170 ℃ + 1050 ℃) + aging heat treatment (DSSA), there were three sizes of γ′ precipitates in thealloy. In general, the SLM + SSA (1130 ℃) alloy obtained the best comprehensive properties, which could be related tothe homogenized microstructures and the uniform and dense distribution of single sized tertiary γ′ precipitates in the alloy.
Abstract
A self-designed nickel-based superalloy, designated as FGH4096M, was prepared by selective laser melting (SLM). Differentheat treatments were performed to improve the mechanical properties of the SLM alloy through optimizing the microstructuresand the features of γ′ precipitates. Compared with the as-deposited alloy, the columnar grains with dendritic structuresand equiaxed structures were retained in the alloy after direct aging, but a large amount of tertiary γ′ phase precipitated,especially around the sub-grain boundaries, resulting in the highest tensile strength but the lowest elongation. During solidsolution and aging treatment (SSA), the recovery and recrystallization occurring in the alloy facilitated the grains to beequiaxed with the increase of solution temperature. For lower solution temperature (below 1100 ℃), the secondary γ′ precipitatesdecreased with the increase of solution temperature, while the tertiary γ′ precipitates from the subsequent agingprocess gradually increased; for higher solution temperature over 1100 ℃, exceeding the complete dissolution temperatureof the γ′ phase, only tertiary γ′ precipitates from the subsequent aging process were uniformly distributed in the alloy. Afterdouble solid solution (1170 ℃ + 1050 ℃) + aging heat treatment (DSSA), there were three sizes of γ′ precipitates in thealloy. In general, the SLM + SSA (1130 ℃) alloy obtained the best comprehensive properties, which could be related tothe homogenized microstructures and the uniform and dense distribution of single sized tertiary γ′ precipitates in the alloy.
- 발행기관:
- 대한금속·재료학회
- 분류:
- 재료공학