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Vacancy-type defects study on ultra-fine grained aluminium processed by severe plastic deformation

Journal Article


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Abstract


  • Vacancy-type defects play an important role in the metal materials deformed by severe plastic deformation

    (SPD). The present work use positron annihilation lifetime spectroscopy (PALS) to test the vacancy-type defects

    in aluminium alloys processed by equal channel angular pressing (ECAP) and accumulative roll bonding (ARB).

    ECAP at room temperature and cryogenic temperature was conducted to AA1050 and ARB with 200 C preheating

    was conducted to AA1050 and AA6061 to produce laminated AA1050 sheets, AA6061 sheets and

    AA1050/AA6061 composites. High fraction of vacancy-type defects were detected in all the deformed samples.

    Vacancies associated with dislocations and bulk mono-vacancies have been identified in RT-ECAP deformed

    samples. Three types of vacancy-type defects, vacancies associated with dislocations, bulk mono-vacancies

    and bulk di-vacancies, have been identified in the CT-ECAP processed samples. The ARB process is more

    efficient in grain refinement and strengthening. However, the accumulation of vacancy-type defects in ARB

    deformation seems less efficient. Vacancies associated with dislocations are the major vacancy-type defects for

    ARB processed AA1050 sheets but there exist some bulk mono-vacancies. However, most of the vacancy-type

    defects in the ARB processed AA6061 are vacancies associated with dislocations. A very small fraction of bulk

    mono-vacancies can be extracted but it is so small that it can be neglected. The lifetimes of ARB processed

    AA1050/AA6061 composites are generally in between the values of AA1050 sheets and AA6061 sheets. Voids

    were not detected in neither of the samples.

Publication Date


  • 2014

Citation


  • Su, L. H., Lu, C., Deng, G. Y., Tieu, K., Zhang, L. C., Guagliardo, P., Samarin, S. & Williams, J. F. (2014). Vacancy-type defects study on ultra-fine grained aluminium processed by severe plastic deformation. Science of Advanced Materials, 6 (7), 1338-1345.

Scopus Eid


  • 2-s2.0-84902968338

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=4622&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/3603

Number Of Pages


  • 7

Start Page


  • 1338

End Page


  • 1345

Volume


  • 6

Issue


  • 7

Abstract


  • Vacancy-type defects play an important role in the metal materials deformed by severe plastic deformation

    (SPD). The present work use positron annihilation lifetime spectroscopy (PALS) to test the vacancy-type defects

    in aluminium alloys processed by equal channel angular pressing (ECAP) and accumulative roll bonding (ARB).

    ECAP at room temperature and cryogenic temperature was conducted to AA1050 and ARB with 200 C preheating

    was conducted to AA1050 and AA6061 to produce laminated AA1050 sheets, AA6061 sheets and

    AA1050/AA6061 composites. High fraction of vacancy-type defects were detected in all the deformed samples.

    Vacancies associated with dislocations and bulk mono-vacancies have been identified in RT-ECAP deformed

    samples. Three types of vacancy-type defects, vacancies associated with dislocations, bulk mono-vacancies

    and bulk di-vacancies, have been identified in the CT-ECAP processed samples. The ARB process is more

    efficient in grain refinement and strengthening. However, the accumulation of vacancy-type defects in ARB

    deformation seems less efficient. Vacancies associated with dislocations are the major vacancy-type defects for

    ARB processed AA1050 sheets but there exist some bulk mono-vacancies. However, most of the vacancy-type

    defects in the ARB processed AA6061 are vacancies associated with dislocations. A very small fraction of bulk

    mono-vacancies can be extracted but it is so small that it can be neglected. The lifetimes of ARB processed

    AA1050/AA6061 composites are generally in between the values of AA1050 sheets and AA6061 sheets. Voids

    were not detected in neither of the samples.

Publication Date


  • 2014

Citation


  • Su, L. H., Lu, C., Deng, G. Y., Tieu, K., Zhang, L. C., Guagliardo, P., Samarin, S. & Williams, J. F. (2014). Vacancy-type defects study on ultra-fine grained aluminium processed by severe plastic deformation. Science of Advanced Materials, 6 (7), 1338-1345.

Scopus Eid


  • 2-s2.0-84902968338

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=4622&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/3603

Number Of Pages


  • 7

Start Page


  • 1338

End Page


  • 1345

Volume


  • 6

Issue


  • 7