Vacancy-induced hardening in Fe-Al alloys

0421498 - ÚFM 2014 RIV GB eng J - Journal Article
Lukáč, F. - Čížek, J. - Procházka, I. - Jirásková, Yvonna - Janičkovič, D. - Anwand, W. - Brauer, G.
Vacancy-induced hardening in Fe-Al alloys.
Journal of Physics: Conference Series. Roč. 443, č. 1 (2013), 012025. ISSN 1742-6588. E-ISSN 1742-6596.
[International Conference on Positron Annihilation /16./. Bristol, 19.08.2012-24.08.2012]
R&D Projects: GA ČR(CZ) GAP108/11/1350
Institutional support: RVO:68081723
Keywords : Vacancy * Hardening * Fe-Al alloy
Subject RIV: BM - Solid Matter Physics ; Magnetism

Hardness of Fe-Al alloys shows a non-trivial dependence on chemical composition and thermal treatment of samples and cannot be fully explained by consideration of intermetallic phases formed according to the equilibrium phase diagram of Fe-Al system. Hardening in Fe- Al alloys caused by quenched-in non-equilibrium vacancies was studied in this work. Non- equilibrium vacancies introduced into the alloys by quenching from 1000 C were detected by means of positron annihilation spectroscopy. The concentration of quenched-in vacancies was found to strongly increase with increasing Al content from 10?5 at.?1 in the alloy with cAl = 18 at. % up to 10?1 at.?1 in the alloy with cAl = 45 at. %. Comparison of the vacancy concentration and the Vickers microhardness revealed that hardening is proportional to square root of concentration of quenched-in vacancies.
Permanent Link: http://hdl.handle.net/11104/0228169