Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading
The low cycle fatigue（LCF） properties of DD6 single crystal superalloy were investigated at 700 ℃ and R of 0.05. SEM was used to study the fracture surface and fracture microstructure. The results show that the LCF life of the alloy decreases with the increase of strain amplitude. LCF properties of...
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| Format: | Article |
| Language: | zho |
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Journal of Aeronautical Materials
2023-10-01
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| Series: | Journal of Aeronautical Materials |
| Subjects: | |
| Online Access: | http://jam.biam.ac.cn/article/doi/10.11868/j.issn.1005-5053.2023.000010 |
| _version_ | 1797663561465462784 |
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| author | LI Wei ZHAO Chunling ZHANG Xin WANG Qiang LI Pu FANG Xiang PENG Wenya |
| author_facet | LI Wei ZHAO Chunling ZHANG Xin WANG Qiang LI Pu FANG Xiang PENG Wenya |
| author_sort | LI Wei |
| collection | DOAJ |
| description | The low cycle fatigue（LCF） properties of DD6 single crystal superalloy were investigated at 700 ℃ and R of 0.05. SEM was used to study the fracture surface and fracture microstructure. The results show that the LCF life of the alloy decreases with the increase of strain amplitude. LCF properties of the alloy are excellent under asymmetrical cyclic loading. The alloy has no transition fatigue life during LCF tests at all total strain amplitudes. LCF fatigue damage can be dominantly contributed to elastic damage and the plastic deformation is very minimal. The plastic damage increases with the increase of total strain amplitude. The crack initiation site, the fatigue crack propagation area and the final fracture zone can be observed in the fracture surface and all specimens is similar to quasi-cleavage fracture. The fatigue cracks are initiated from the micro-pores on the surface, sub-surface or far from the surface. Far from the surface crack fractures have fish-eye feature. The fatigue crack propagates perpendicularly to main stress at first and then along {111} plane. Typical fatigue striation, cleavage steps and river pattern characteristic are formed on fatigue crack propagation zone. The cleavage plane, slip band and tearing ridge are seen in the final fracture zone. Fracture microstructure analysis shows that the γ′ phase morphology far from the fracture surface still maintains cubic shape， and the slip bands are visible seen near the fracture surface， and secondary cracks are formed along slip bands. |
| first_indexed | 2024-03-11T19:16:28Z |
| format | Article |
| id | doaj.art-bbd48d9167174835929421076fda0df8 |
| institution | Directory Open Access Journal |
| issn | 1005-5053 |
| language | zho |
| last_indexed | 2024-03-11T19:16:28Z |
| publishDate | 2023-10-01 |
| publisher | Journal of Aeronautical Materials |
| record_format | Article |
| series | Journal of Aeronautical Materials |
| spelling | doaj.art-bbd48d9167174835929421076fda0df82023-10-09T08:50:06ZzhoJournal of Aeronautical MaterialsJournal of Aeronautical Materials1005-50532023-10-01435586610.11868/j.issn.1005-5053.2023.0000102023-0010Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loadingLI Wei0ZHAO Chunling1ZHANG Xin2WANG Qiang3LI Pu4FANG Xiang5PENG Wenya6AECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaAECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaAECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaAECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaAECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaAECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaAECC Hunan Aviation Powerplant Research Institute, Zhuzhou 412000, Hunan, ChinaThe low cycle fatigue（LCF） properties of DD6 single crystal superalloy were investigated at 700 ℃ and R of 0.05. SEM was used to study the fracture surface and fracture microstructure. The results show that the LCF life of the alloy decreases with the increase of strain amplitude. LCF properties of the alloy are excellent under asymmetrical cyclic loading. The alloy has no transition fatigue life during LCF tests at all total strain amplitudes. LCF fatigue damage can be dominantly contributed to elastic damage and the plastic deformation is very minimal. The plastic damage increases with the increase of total strain amplitude. The crack initiation site, the fatigue crack propagation area and the final fracture zone can be observed in the fracture surface and all specimens is similar to quasi-cleavage fracture. The fatigue cracks are initiated from the micro-pores on the surface, sub-surface or far from the surface. Far from the surface crack fractures have fish-eye feature. The fatigue crack propagates perpendicularly to main stress at first and then along {111} plane. Typical fatigue striation, cleavage steps and river pattern characteristic are formed on fatigue crack propagation zone. The cleavage plane, slip band and tearing ridge are seen in the final fracture zone. Fracture microstructure analysis shows that the γ′ phase morphology far from the fracture surface still maintains cubic shape， and the slip bands are visible seen near the fracture surface， and secondary cracks are formed along slip bands.http://jam.biam.ac.cn/article/doi/10.11868/j.issn.1005-5053.2023.000010dd6single crystal superalloyasymmetrical cyclic loadinglow cycle fatiguefracture mechanism |
| spellingShingle | LI Wei ZHAO Chunling ZHANG Xin WANG Qiang LI Pu FANG Xiang PENG Wenya Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading Journal of Aeronautical Materials dd6 single crystal superalloy asymmetrical cyclic loading low cycle fatigue fracture mechanism |
| title | Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading |
| title_full | Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading |
| title_fullStr | Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading |
| title_full_unstemmed | Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading |
| title_short | Low cycle fatigue properties and fatigue mechanism of DD6 single crystal superalloy under asymmetrical cyclic loading |
| title_sort | low cycle fatigue properties and fatigue mechanism of dd6 single crystal superalloy under asymmetrical cyclic loading |
| topic | dd6 single crystal superalloy asymmetrical cyclic loading low cycle fatigue fracture mechanism |
| url | http://jam.biam.ac.cn/article/doi/10.11868/j.issn.1005-5053.2023.000010 |
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