Irradiation-induced precipitation in V–4Cr–4Ti alloys studied using three-dimensional atom probe

Abstract To investigate neutron irradiation effects on the precipitation behavior of Ti(O,N,C) in V–4Cr–4Ti alloy, chemical and structural analyses were conducted using a laser-assisted local electrode three-dimensional atom probe. Ti(O,N,C) precipitates were observed after irradiation at 333 and 673 K. These NaCl-type precipitates mostly consisted of V, Ti, Cr, O, and C. The chemical composition of the precipitate was estimated as about V 39 Cr 2 Ti 5 CO 3 at both irradiation temperatures. This result suggests that most of the Ti sublattice presumed to be replaced by V and O, N, and C sublattice are instead occupied by vacancies. Therefore, compositionally modified V 39 Cr 2 Ti 5 CO 3 precipitates might form with larger volume fractions than TiO precipitates.