Propagation of corrosion induced fatigue crack in aluminum alloy
Aluminium is considered a green metal due to its environmental responsive characteristics. The 7475-T7351 aluminum alloy is extensively used in automotive and aerospace applications due to its light weight and high strength. In the present work, the effects of the corrosive environment on the hig...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
AIMS Press
2022-08-01
|
| Series: | AIMS Materials Science |
| Subjects: | |
| Online Access: | https://www.aimspress.com/article/doi/10.3934/matersci.2022030?viewType=HTML |
| _version_ | 1828355760436805632 |
|---|---|
| author | Pawan Kumar BB Verma |
| author_facet | Pawan Kumar BB Verma |
| author_sort | Pawan Kumar |
| collection | DOAJ |
| description | Aluminium is considered a green metal due to its environmental responsive characteristics.
The 7475-T7351 aluminum alloy is extensively used in automotive and aerospace applications due to
its light weight and high strength. In the present work, the effects of the corrosive environment on the
high cycle fatigue (HCF) behaviors of the 7475-T7351 aluminum alloy was investigated. The aqueous
solution of sodium chloride was used for solution treatment. The HCF test was performed on
pre-cracked specimens using a servo-hydraulic universal testing machine, Instron 8800. The fractured
specimens were characterized using a scanning electron microscope. It was observed that the crack
propagation occurred through anodic dissolution at high stress and a significant crack tip blunting and
crack extension occurred. However, no appreciable change in crack growth was noticed over the lower
frequency range of 0.1 to 0.9 Hz. The slower growth rate envisages oxide debris formation between
the cracked faces. When the alloy was treated under corrosive environments, the HCF tests depicted
that the fatigue life reduces up to two orders of magnitude. The corrosion pits induced the crack
initiation in stage-I at lower alternating stress; however, the fatigue crack growth rate (FCGR) was
increased in the corrosive environment. The transition from stage-I to stage-II occurred at a lower
stress intensity range (∆K) level; it was due to the combined effects of corrosion, hydrogen
embrittlement, active path dissolution, and stress concentration. The corrosion fatigue test at low
frequency also depicted a slower FCGR as compared to its moderate frequency counterpart and showed
an irregular crack growth behavior. |
| first_indexed | 2024-04-14T02:47:49Z |
| format | Article |
| id | doaj.art-425af1832d384db3a36e3ac3cf0563db |
| institution | Directory Open Access Journal |
| issn | 2372-0484 |
| language | English |
| last_indexed | 2024-04-14T02:47:49Z |
| publishDate | 2022-08-01 |
| publisher | AIMS Press |
| record_format | Article |
| series | AIMS Materials Science |
| spelling | doaj.art-425af1832d384db3a36e3ac3cf0563db2022-12-22T02:16:26ZengAIMS PressAIMS Materials Science2372-04842022-08-019351252110.3934/matersci.2022030Propagation of corrosion induced fatigue crack in aluminum alloyPawan Kumar0BB Verma11. University of Johannesburg, Faculty of Engineering and the Built Environment, Department of Engineering Metallurgy, John Orr Building, DFC, 25 Louisa St, Doornfontein, Johannesburg, 2028, South Africa2. Department of Metallurgical and Materials Engineering, National Institute of Technology Rourkela 76908, IndiaAluminium is considered a green metal due to its environmental responsive characteristics. The 7475-T7351 aluminum alloy is extensively used in automotive and aerospace applications due to its light weight and high strength. In the present work, the effects of the corrosive environment on the high cycle fatigue (HCF) behaviors of the 7475-T7351 aluminum alloy was investigated. The aqueous solution of sodium chloride was used for solution treatment. The HCF test was performed on pre-cracked specimens using a servo-hydraulic universal testing machine, Instron 8800. The fractured specimens were characterized using a scanning electron microscope. It was observed that the crack propagation occurred through anodic dissolution at high stress and a significant crack tip blunting and crack extension occurred. However, no appreciable change in crack growth was noticed over the lower frequency range of 0.1 to 0.9 Hz. The slower growth rate envisages oxide debris formation between the cracked faces. When the alloy was treated under corrosive environments, the HCF tests depicted that the fatigue life reduces up to two orders of magnitude. The corrosion pits induced the crack initiation in stage-I at lower alternating stress; however, the fatigue crack growth rate (FCGR) was increased in the corrosive environment. The transition from stage-I to stage-II occurred at a lower stress intensity range (∆K) level; it was due to the combined effects of corrosion, hydrogen embrittlement, active path dissolution, and stress concentration. The corrosion fatigue test at low frequency also depicted a slower FCGR as compared to its moderate frequency counterpart and showed an irregular crack growth behavior. https://www.aimspress.com/article/doi/10.3934/matersci.2022030?viewType=HTMLaluminium alloysolution treatmenthigh cycle fatiguemicrostructure |
| spellingShingle | Pawan Kumar BB Verma Propagation of corrosion induced fatigue crack in aluminum alloy AIMS Materials Science aluminium alloy solution treatment high cycle fatigue microstructure |
| title | Propagation of corrosion induced fatigue crack in aluminum alloy |
| title_full | Propagation of corrosion induced fatigue crack in aluminum alloy |
| title_fullStr | Propagation of corrosion induced fatigue crack in aluminum alloy |
| title_full_unstemmed | Propagation of corrosion induced fatigue crack in aluminum alloy |
| title_short | Propagation of corrosion induced fatigue crack in aluminum alloy |
| title_sort | propagation of corrosion induced fatigue crack in aluminum alloy |
| topic | aluminium alloy solution treatment high cycle fatigue microstructure |
| url | https://www.aimspress.com/article/doi/10.3934/matersci.2022030?viewType=HTML |
| work_keys_str_mv | AT pawankumar propagationofcorrosioninducedfatiguecrackinaluminumalloy AT bbverma propagationofcorrosioninducedfatiguecrackinaluminumalloy |