Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures
Intermediate temperature embrittlement (ITE) is very common in Ni and Ni–Co based superalloys, which seriously restricts the application of these alloys. In this work, we developed a new Ni–Co based superalloy by increasing the content of Cr to eliminate ITE. The superalloy has a yield strength of ∼...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-03-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785424003181 |
| _version_ | 1797247871039307776 |
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| author | Zhongrun Xiao Junyang He Ji Gu Bin Gan Min Song |
| author_facet | Zhongrun Xiao Junyang He Ji Gu Bin Gan Min Song |
| author_sort | Zhongrun Xiao |
| collection | DOAJ |
| description | Intermediate temperature embrittlement (ITE) is very common in Ni and Ni–Co based superalloys, which seriously restricts the application of these alloys. In this work, we developed a new Ni–Co based superalloy by increasing the content of Cr to eliminate ITE. The superalloy has a yield strength of ∼950 MPa in the intermediate temperature range (600–780 °C), while also maintain a tensile elongation of ∼15 %. Microstructural investigations showed that in the temperature range of 600–780 °C, the microstructure of the alloy consists of nano-sized L12 phase (γ′) distributing inside the γ matrix, and the deformation is dominated by anti-phase boundary (APB) shearing γ′ precipitates, which makes the yield strength of the alloy decrease only slightly at 600–780 °C (compared to that tested at room temperature). More importantly, the element Cr is enriched along the grain boundaries (GBs) to form a protective layer without the formation of brittle topologically close-packed (TCP) phases due to the inverse two-stage aging design. In addition, the formation of a discontinuous precipitation (DP) zone at the GBs can act as a stress buffer and introduce GB serrations to withstand intergranular cracking. |
| first_indexed | 2024-03-08T03:36:08Z |
| format | Article |
| id | doaj.art-5bc96696c6fd4bd3a7bbee3a3fc940eb |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-04-24T20:05:34Z |
| publishDate | 2024-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-5bc96696c6fd4bd3a7bbee3a3fc940eb2024-03-24T06:58:02ZengElsevierJournal of Materials Research and Technology2238-78542024-03-012926202627Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperaturesZhongrun Xiao0Junyang He1Ji Gu2Bin Gan3Min Song4State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, ChinaState Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, ChinaState Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, ChinaBeijing Key Laboratory of Advanced High Temperature Materials, Central Iron and Steel Research Institute, Beijing, 100081, China; Corresponding author.State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, China; Corresponding author.Intermediate temperature embrittlement (ITE) is very common in Ni and Ni–Co based superalloys, which seriously restricts the application of these alloys. In this work, we developed a new Ni–Co based superalloy by increasing the content of Cr to eliminate ITE. The superalloy has a yield strength of ∼950 MPa in the intermediate temperature range (600–780 °C), while also maintain a tensile elongation of ∼15 %. Microstructural investigations showed that in the temperature range of 600–780 °C, the microstructure of the alloy consists of nano-sized L12 phase (γ′) distributing inside the γ matrix, and the deformation is dominated by anti-phase boundary (APB) shearing γ′ precipitates, which makes the yield strength of the alloy decrease only slightly at 600–780 °C (compared to that tested at room temperature). More importantly, the element Cr is enriched along the grain boundaries (GBs) to form a protective layer without the formation of brittle topologically close-packed (TCP) phases due to the inverse two-stage aging design. In addition, the formation of a discontinuous precipitation (DP) zone at the GBs can act as a stress buffer and introduce GB serrations to withstand intergranular cracking.http://www.sciencedirect.com/science/article/pii/S2238785424003181Ni-Co based superalloysHigh temperature tensionEmbrittlementFractureDeformation mechanisms |
| spellingShingle | Zhongrun Xiao Junyang He Ji Gu Bin Gan Min Song Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures Journal of Materials Research and Technology Ni-Co based superalloys High temperature tension Embrittlement Fracture Deformation mechanisms |
| title | Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures |
| title_full | Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures |
| title_fullStr | Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures |
| title_full_unstemmed | Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures |
| title_short | Microstructure and mechanical properties of a new Ni–Co based superalloy at intermediate temperatures |
| title_sort | microstructure and mechanical properties of a new ni co based superalloy at intermediate temperatures |
| topic | Ni-Co based superalloys High temperature tension Embrittlement Fracture Deformation mechanisms |
| url | http://www.sciencedirect.com/science/article/pii/S2238785424003181 |
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