Vacancy-induced hardening in Fe-Al alloys

16th International Conference on Positron Annihilation

Lukác, F.^1 ; Cízek, J.^1 ; Procházka, I.^1 ; Jirásková, Y.^2 ; Janickovic, D.^3 ; Anwand, W.^4 ; Brauer, G.^4

Charles University in Prague, Faculty of Mathematics and Physics, V Holeovickách 2, 18000 Praha 8, Czech Republic^1

Institute of Physics of Materials, Academy of Science of the Czech Republic, Zizkova 513/22, Brno, 61662, Czech Republic^2

Institute of Physics, Slovak Academy of Science, Dúbravská cesta 9, 84511 Bratislava, Slovakia^3

Institut fur Strahlenphysik, Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, D-01314 Dresden, Germany^4

关键词: Chemical compositions;    Equilibrium phase diagrams;    Intermetallic phasis;    Non equilibrium;    Non-trivial dependence;    Quenched-in vacancies;    Vacancy concentration;    Vickers microhardness;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012025/pdf
DOI  :  10.1088/1742-6596/443/1/012025

来源: IOP

【 摘 要 】

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 10-5at.-1in the alloy with cAl= 18 at. % up to 10-1at.-1in 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.