Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography
Hot tears can arise during the late part of alloy solidification because of the shrinkage of isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations to suggest alloy hot tear sensitivity to casting conditions, they do not ca...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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Elsevier
2023
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| _version_ | 1797111502449147904 |
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| author | Han, I Feng, S Wilde, F Grant, PS Liotti, E |
| author_facet | Han, I Feng, S Wilde, F Grant, PS Liotti, E |
| author_sort | Han, I |
| collection | OXFORD |
| description | Hot tears can arise during the late part of alloy solidification because of the shrinkage of isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations to suggest alloy hot tear sensitivity to casting conditions, they do not capture the influence of microstructure on tearing, such as second-phase particles or intermetallic compounds (IMCs) commonly present in engineering alloys. We use in situ X-ray radiography to quantify the formation and growth behaviour of hot tears in Al-5Cu and Al-5Cu-1Fe alloys during solidification. An automated hot tear detection, tracking and merging algorithm is developed and applied to reveal the role of Fe-rich IMC particles, typical of recycled alloys, on hot tear behaviour. These defects are termed hot tears here on the basis of their complex, extended inter-connected morphology, distinct from more rounded shrinkage porosity. We also visualise and quantify the velocity of interdendritic flow driven by solidification shrinkage, and estimate the pressure changes due to shrinkage. Hot tearing starts at lower solid fraction when IMCs are present due to reduced interdendritic flow, and hot tear formation is more spatially homogeneous, less clustered and more numerous. We show that the largest, most damaging hot tears form from many merging events, that is enhanced by the presence of IMCs. |
| first_indexed | 2024-03-07T08:11:19Z |
| format | Journal article |
| id | oxford-uuid:90c50202-75f4-4095-afbf-0411bf76a97d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T08:11:19Z |
| publishDate | 2023 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:90c50202-75f4-4095-afbf-0411bf76a97d2023-11-23T11:20:34ZRevealing hot tear formation dynamics in Al–Cu alloys with X-ray radiographyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:90c50202-75f4-4095-afbf-0411bf76a97dEnglishSymplectic ElementsElsevier2023Han, IFeng, SWilde, FGrant, PSLiotti, EHot tears can arise during the late part of alloy solidification because of the shrinkage of isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations to suggest alloy hot tear sensitivity to casting conditions, they do not capture the influence of microstructure on tearing, such as second-phase particles or intermetallic compounds (IMCs) commonly present in engineering alloys. We use in situ X-ray radiography to quantify the formation and growth behaviour of hot tears in Al-5Cu and Al-5Cu-1Fe alloys during solidification. An automated hot tear detection, tracking and merging algorithm is developed and applied to reveal the role of Fe-rich IMC particles, typical of recycled alloys, on hot tear behaviour. These defects are termed hot tears here on the basis of their complex, extended inter-connected morphology, distinct from more rounded shrinkage porosity. We also visualise and quantify the velocity of interdendritic flow driven by solidification shrinkage, and estimate the pressure changes due to shrinkage. Hot tearing starts at lower solid fraction when IMCs are present due to reduced interdendritic flow, and hot tear formation is more spatially homogeneous, less clustered and more numerous. We show that the largest, most damaging hot tears form from many merging events, that is enhanced by the presence of IMCs. |
| spellingShingle | Han, I Feng, S Wilde, F Grant, PS Liotti, E Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography |
| title | Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography |
| title_full | Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography |
| title_fullStr | Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography |
| title_full_unstemmed | Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography |
| title_short | Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography |
| title_sort | revealing hot tear formation dynamics in al cu alloys with x ray radiography |
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