Vacancy-solute interactions during ageing of a cold-worked Mg-RE-based alloy

被引：4
作者：
Moia, F. [1 ,2 ]
Ferragut, R. [1 ,2 ]
Calloni, A. [1 ,2 ]
Dupasquier, A. [1 ,2 ]
Macchi, C. E. [3 ,4 ]
Somoza, A. [4 ,5 ]
Nie, J. F. [6 ]
机构：
[1] Politecn Milan, Dipartimento Fis, LNESS, I-22100 Como, Italy
[2] Politecn Milan, CNISM, I-22100 Como, Italy
[3] Consejo Nacl Invest Cient & Tecn, Tandil, Argentina
[4] UNCtr, IFIMAT, Tandil, Argentina
[5] CICPBA, Tandil, Argentina
[6] Monash Univ, Dept Mat Engn, Clayton, Vic 3800, Australia
来源：
PHILOSOPHICAL MAGAZINE | 2010年 / 90卷 / 16期
关键词：
magnesium alloys; positron annihilation; precipitation; POSITRON; PRECIPITATION;
D O I：
10.1080/14786430903581320
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The vacancy-solute interactions during artificial ageing at 250 degrees C of cold worked samples of a commercial magnesium alloy WE54 (Mg-RE based) were studied by coincidence Doppler broadening of positron annihilation radiation and positron annihilation lifetime spectroscopy. The results show that, in the as-cold-worked state, the vacancies are associated with dislocations that are generated by the cold work and that, after artificial ageing at 250 degrees C, the vacancies are associated with solute elements and help the formation of precipitate precursors. This mechanism accelerates the formation of hardening precipitates without any apparent changes in the precipitation sequence and in the products of the decomposition of the supersaturated solid solution. The present study demonstrates that the stronger hardening response achieved in the cold-worked samples originates from the presence of a higher concentration of vacancies that is introduced by the cold work and is retained in the first few minutes of ageing.
引用
收藏
页码：2135 / 2147
页数：13
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