Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment
The microstructure and mechanical properties of additively manufactured (AM) components often exhibit inherent heterogeneity due to their complex thermal histories. Building on conventional heat treatment strategies to mitigate microstructural heterogeneity, this study employed a continuous laser fo...
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Taylor & Francis Group
2025-12-01
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| Series: | Virtual and Physical Prototyping |
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| Online Access: | https://www.tandfonline.com/doi/10.1080/17452759.2025.2509614 |
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| author | Chen Yang Haibo Tang Zhuo Li Ziheng Zeng Shujing Shi Yansong Zhang Chunjie Shen |
| author_facet | Chen Yang Haibo Tang Zhuo Li Ziheng Zeng Shujing Shi Yansong Zhang Chunjie Shen |
| author_sort | Chen Yang |
| collection | DOAJ |
| description | The microstructure and mechanical properties of additively manufactured (AM) components often exhibit inherent heterogeneity due to their complex thermal histories. Building on conventional heat treatment strategies to mitigate microstructural heterogeneity, this study employed a continuous laser forming method coupled with enhanced heat accumulation and the resulting in-situ heat treatment (IHT) to homogenise AM DD98 m samples. Results demonstrate that heat accumulation stabilises cooling rates at ∼65 K/s and maintains primary dendrite arm spacing (PDAS) at ∼55 μm. By promoting solid-state elemental diffusion, IHT significantly reduces elemental segregation, leading to extensive dissolution of γ-γ′ eutectic phases. Due to the IHT, the γ’ phase exhibits consistent volume fractions and comparable precipitate size distribution across specimens, yielding relatively homogeneous microhardness throughout the samples. Notably, the layered γ′ phase, previously underexplored in literature, is attributed to IHT-induced local Ostwald ripening, driven by aluminium (Al) diffusion gradients. This work successfully utilises IHT to control solid-state phase transformations, thereby reducing AM component heterogeneity. The findings advance strategies for tailoring microstructural uniformity in additive manufacturing, offering a novel pathway to mitigate microstructural heterogeneity in superalloys. |
| format | Article |
| id | doaj-art-3d8ed1fd1fc04458ae1dbe8e30cae648 |
| institution | OA Journals |
| issn | 1745-2759 1745-2767 |
| language | English |
| publishDate | 2025-12-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Virtual and Physical Prototyping |
| spelling | doaj-art-3d8ed1fd1fc04458ae1dbe8e30cae6482025-08-20T02:37:41ZengTaylor & Francis GroupVirtual and Physical Prototyping1745-27591745-27672025-12-0120110.1080/17452759.2025.2509614Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatmentChen Yang0Haibo Tang1Zhuo Li2Ziheng Zeng3Shujing Shi4Yansong Zhang5Chunjie Shen6National Engineering Laboratory of Additive Manufacturing for Large Metallic Components, School of Materials Science and Engineering, Beihang University, Beijing, People’s Republic of ChinaNational Engineering Laboratory of Additive Manufacturing for Large Metallic Components, School of Materials Science and Engineering, Beihang University, Beijing, People’s Republic of ChinaNational Engineering Laboratory of Additive Manufacturing for Large Metallic Components, School of Materials Science and Engineering, Beihang University, Beijing, People’s Republic of ChinaNational Engineering Laboratory of Additive Manufacturing for Large Metallic Components, School of Materials Science and Engineering, Beihang University, Beijing, People’s Republic of ChinaNingbo Institute of Technology, Beihang University, Ningbo, People’s Republic of ChinaNational Engineering Laboratory of Additive Manufacturing for Large Metallic Components, School of Materials Science and Engineering, Beihang University, Beijing, People’s Republic of ChinaNational Engineering Laboratory of Additive Manufacturing for Large Metallic Components, School of Materials Science and Engineering, Beihang University, Beijing, People’s Republic of ChinaThe microstructure and mechanical properties of additively manufactured (AM) components often exhibit inherent heterogeneity due to their complex thermal histories. Building on conventional heat treatment strategies to mitigate microstructural heterogeneity, this study employed a continuous laser forming method coupled with enhanced heat accumulation and the resulting in-situ heat treatment (IHT) to homogenise AM DD98 m samples. Results demonstrate that heat accumulation stabilises cooling rates at ∼65 K/s and maintains primary dendrite arm spacing (PDAS) at ∼55 μm. By promoting solid-state elemental diffusion, IHT significantly reduces elemental segregation, leading to extensive dissolution of γ-γ′ eutectic phases. Due to the IHT, the γ’ phase exhibits consistent volume fractions and comparable precipitate size distribution across specimens, yielding relatively homogeneous microhardness throughout the samples. Notably, the layered γ′ phase, previously underexplored in literature, is attributed to IHT-induced local Ostwald ripening, driven by aluminium (Al) diffusion gradients. This work successfully utilises IHT to control solid-state phase transformations, thereby reducing AM component heterogeneity. The findings advance strategies for tailoring microstructural uniformity in additive manufacturing, offering a novel pathway to mitigate microstructural heterogeneity in superalloys.https://www.tandfonline.com/doi/10.1080/17452759.2025.2509614Nickel-based superalloyslaser-directed energy depositionheat accumulation in-situ heat treatmentheterogeneitiessolid phase transformation |
| spellingShingle | Chen Yang Haibo Tang Zhuo Li Ziheng Zeng Shujing Shi Yansong Zhang Chunjie Shen Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment Virtual and Physical Prototyping Nickel-based superalloys laser-directed energy deposition heat accumulation in-situ heat treatment heterogeneities solid phase transformation |
| title | Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment |
| title_full | Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment |
| title_fullStr | Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment |
| title_full_unstemmed | Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment |
| title_short | Mitigating microstructural heterogeneity in laser-directed energy deposition Ni-based superalloys by heat accumulation in-situ heat treatment |
| title_sort | mitigating microstructural heterogeneity in laser directed energy deposition ni based superalloys by heat accumulation in situ heat treatment |
| topic | Nickel-based superalloys laser-directed energy deposition heat accumulation in-situ heat treatment heterogeneities solid phase transformation |
| url | https://www.tandfonline.com/doi/10.1080/17452759.2025.2509614 |
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