[Wang, B. Y.
; Wang, D. N.
; Zhang, L. Z.
; Qin, X. B.] Chinese Acad Sci, Inst High Energy Phys, Key Lab Nucl Anal Tech, Beijing 100049, Peoples R China
; [Li, Z. X.
; Xue, D. S.] Lanzhou Univ, Minist Educ China, Key Lab Magnetism & Magnet Mat, Lanzhou 730000, Peoples R China
Defects of doped and neutron-irradiated TiAl alloys were investigated using positron annihilation lifetime and coincidence doppler broadening spectroscopies In doped alloys, niobium additions replaced some atoms in the lattice, which maintains the ordered structure as undoped, while silicon additions Induced Ti vacancies After neutron irradiation, a number of vacancy-type defects were Introduced, including some large vacancies, which can be congregated and hardly be eliminated by annealing at temperature above 1000 K The vacancy-type defects in (Ti(51)Al(49))(98)Si(2) began to migrate at 452 K, which is lower than in Ti(51)Al(49) alloy This probably resulted from vacancies induced by the addition of silicon, which facilitated atom migration and decreased initial recovery temperature. (C) 2010 Elsevier Ltd. All rights reserved.