- Tytuł:
- Electrical Resistivity and Positron Lifetime Studies of Precipitation Effects in Al-Cu Alloy
- Autorzy:
-
Αda, P.
Cieslar, M.
Vostrý, P.
Bečvář, F.
Νovotný, I.
Procházka, I. - Powiązania:
- https://bibliotekanauki.pl/articles/1933483.pdf
- Data publikacji:
- 1995-07
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
61.72.-y
78.70.-g
81.40.-z - Opis:
- Decomposition of the supersaturated solid solution of 2 at.% Cu in Al was investigated by means of electrical resistivity and high-resolution positron lifetime measurements. The phase composition of this alloy was determined by transmission electron microscopy. Electrical resistivity measurements were performed by a classical four-point method. Positron lifetime spectra were measured by means of a spectrometer consisting of two BaF$\text{}_{2}$ detectors and a standard fast-slow coincidence system. The specimens were first exposed to the solution heat treatment at 783 K for 19 hours with a subsequent quenching. Then the specimens were isochronally annealed in the temperature range 293 ÷ 573 K. Annealing responses of electrical resistivity and positron annihilation were studied. Resistivity measurements as well as transmission electron microscopy observations confirmed the well-known decomposition sequence of the Al-Cu alloy. The decomposition of the alloy was manifested by the decrease in the intensity of positron lifetime component τ$\text{}_{2}$ = (207 ±2 ) ps correlated with simultaneous appearance and increase in the intensity of τ$\text{}_{3}$ = (180 ± 5) ps component. Component τ$\text{}_{2}$ originates from positron annihilation in vacancies trapped at the Guinier-Preston zones while τ$\text{}_{3}$ comes from annihilation of the positrons localized in the misfit dislocations at coherent precipitates of the Al$\text{}_{2}$Cu phase. The shortest observed component τ$\text{}_{1}$ apparently belongs to annihilation of untrapped positrons.
- Źródło:
-
Acta Physica Polonica A; 1995, 88, 1; 111-117
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł